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Fruit TreesAphids, shoots on apple tree roots
Apple tree bark damaged by freeze
Apple tree watersprouts
Apples fall off early
Bradford pear tree, yellow leaves
Cherry (or peach) from pits
Cherries all dropped off tree
Cherry shortage
Failed cherry crop
Fall tree planting
Fig Tree: starting a new one
Fig tree winter protection
Fruit trees: how long to fruit?
Fruit tree branches break under load
Lemon tree from seed
Lemon trees, growing indoors
Peach tree: starting a new one
Pear tree, damaged leaves
Prune cherry tree
Pruning – apple trees?
Spraying fruit trees
Sugar maple tree
Tomato tree?
Water for fruit tree, how much?
Aphids, shoots on apple tree roots 8-98
Q. I have had numerous sprouts come up from my apple tree. I decided to dig some of them to transplant so that I could have more apple trees. This is a very good apple and I wanted more. When I dug the sprouts, I discovered that they were attached to large roots from the tree and that these large roots had knots, or tumors, on them. I also noticed some white, fuzzy, things on these knots. Did I hurt my tree by digging these roots up? The tree has been losing branches for the last few years, and I wonder if it was too weak to have the roots damaged like that. By the way, what causes the knots on the roots?
A. While I would not recommend digging the large roots from under an apple, or any other tree, in this case you probably did less damage than the "woolly apple aphids" that you described. These are aphids that attack apples and cause serious problems. They can attack the bark, twigs, and the roots. In the roots they cause galling, or the formation of the knots that you described. These galls interfere with the flow of water and minerals from the roots to the top of the tree, probably explaining why you have seen branch dieback.
The woolly apple aphid is a small insect which covers itself with white, waxy filaments which give it the "woolly" appearance. Their color varies with the seasons and whether the aphids are winged or without wings. These colors range from dusky green and dusky brown, to pinkish, reddish, to rusty yellow or brown. However, the waxy coating usually conceals these colors, and their small size makes the color less important unless you observe them through a microscope.
On the apple trees, they are commonly found on the twigs, roots, and especially in crevices in the bark where they may be numerous. Even if not observed above ground, they may be present on the roots and causing problems like you have described. One of the symptoms of their presence underground, though also a symptom of other things, is the development of numerous sprouts from the roots where the galls have formed.
According to Dr. Mike English, NMSU Extension Entomologist, once the roots are infested, the tree is doomed to a slow death. It is not possible with reasonable means to eradicate the aphids from the roots. In time the tree will die. Initially individual branches will die and leaves will drop from other branches. In spite of infestation, the tree can continue to grow and produce apples for years.
Crown gall is a disease of apples and other members of the rose family. This disease causes the formation of galls on the roots, base of the trunk, and sometimes on the branches of the trees. It may be confused with the woolly apple aphid galls, but the white, waxy covered, insects are not present. Since you described the presence of the insects, they are the most likely cause of your problem.
Regarding your plan to dig the sprouts to start new trees, these sprouts are from the rootstock and will not produce the tasty apples you described unless the tree was started from seed and never grafted. If these are from the rootstock, the new plants would need to be grafted with the variety that you like. However, you now know that this rootstock is susceptible to the woolly apple aphid, and these sprouts are probably infested, so I would not recommend using them. The solution to the problem is to plant apple trees grafted onto woolly apple aphid resistant rootstocks. When you plant new trees and when it is time to replace the tree you wrote about, if you choose to plant apples, be sure to use the resistant rootstocks.
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Apple tree bark damaged by freeze 8-98
Q. I live in Taos on the mesa. I planted a golden delicious apple tree last fall. This summer I have noticed serious damage to the bark like something is destroying it, but I have not seen an insect infestation. It is continuing to put out new growth, but I am concerned about the damage to the outer layer of bark.
A. I need to ask a few questions: (1) Do you see teeth marks in the bark to indicate that a larger animal, rabbit or such, is chewing? (2) Have you tried any insecticides? (3) On which side of the trunk (geographic direction - N, S, E, W) does the injury appear? I ask these questions because they may help identify the problem. Without your answers, however, I will guess that the damage is on the south to southwest side of the trunk or the side that was to the south in the nursery before you planted them. Trees in New Mexico, especially newly planted trees and trees waiting in the nursery, are subject to a form of winter injury we call "southwest injury" because it occurs on the south to southwest side of the trunk. This injury develops because the bark exposed to the sunlight in the winter warms during the day, then freezes again each night. This alternate freezing and thawing kills the layer of tissue just under the bark. Then, as summer progresses, the bark begins to die and peel or flake off, so the symptoms may not appear until several months after the damage is done.
If no clear signs of animal or insect damage are present, I would suspect this southwest injury. The injured bark will be slow to repair, but in time new bark may grow over the injured area. To limit these problems, you might try painting the trunk of the tree with a cheap, water-based, white latex paint late next fall. This will reflect the heat during the day and reduce the temperature fluctuations.
I suggest that you also contact a local Extension Service person to take a look at the trees. Seeing them, they can do a better job of diagnosis. They also have resources, including me, to help them with the diagnosis.
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Apple tree has watersprouts 5-01
Q. My apple tree has some new stems that grew straight up from the branches last year. They don’t look productive and have ruined the shape of the tree. Why did this happen and what should I do?
A. These are watersprouts which usually result from the tree’s attempt to recover from heavy pruning. They can occur without pruning, but they are less common without heavy pruning. Watersprouts are usually non-productive for a few years but in time will become productive. You can prune, removing them at the point at which they developed from the other branches, or you can cut them just above a bud (a foot or more above the point of origination in a location where they will not damage the form of the tree).
You can prune to keep the branch if it is in a good location where it doesn’t rub on other branches or is not too shaded by other branches. In a couple of years it should develop blossoms and begin producing fruit. It is too late for this type of pruning in most of New Mexico since leaf and flower growth has already begun. If essential, they can be pruned now; otherwise, wait until next fall when the tree is dormant. If new watersprouts develop this year, remove them in the summer while they are still small, tender and green.
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Apples fall from the tree early 11-00
Q. I have a Red Delicious apple tree in my yard. I am guessing that the tree is 30 years old or more, but no older than 40. We first moved into our house 10 years ago, and that year's crop of apples was full of worms but were very tasty and extremely large. Since that year, the apples bloom and I get a great fruit set; however, by mid summer the apples start to fall off the tree at a rate such that I have no crop to pick by the end of summer. Some of the apples even rot on the tree, so by the time they fall and hit the ground, they look like apple sauce.
Another consideration is the fact that after I moved to the house I took out the grass that was under the tree and put pea gravel around the tree and a majority of the surrounding area. The area is very shaded from other trees in the area which keeps the gravel cooler than if in the direct sunlight; however, it is now hotter than when the grass was there. What could be the problem and how could I correct it?
A. There are several things that could be contributing to the problem. One of them is the worms you mentioned. The fact that many of the apples rot while still on the tree suggests that the codling moth larvae (worms) are infesting them. Apples infested with codling moths will have rotten areas within the developing fruit and will often drop from the tree. The gravel under the tree may be a contributing factor by providing a place for the larvae to pupate and develop into moths which will lay eggs in the next year’s crop. I conferred with Bob Cain, NMSU Extension Forest Entomologist, and Carol Sutherland, NMSU Extension Entomologist. Dr. Sutherland reported that codling moth infestations can cause 100 percent crop loss as you are describing. Both agreed that the gravel might create an increased problem by providing a safe place for the moth larvae to pupate. They also stated that the most common place for the larvae to pupate is on the branches and trunk.
It is important to remove fallen fruit (even small apples) as soon as they fall so that the codling moth larvae are removed from the vicinity of the tree. Failure to do so allows the codling moths to increase to harmful population levels near your tree. If you wish to compost the fallen apples, be certain that they are placed into a hot part of the compost pile where the larvae will be killed by the heat. Otherwise, they will pupate in the cool part of the compost pile and emerge as adult codling moths to lay eggs in your apple tree next year.
Treatment with an insecticide for codling moth management may be necessary. If you decide to use an insecticide, choose a product labeled for controlling codling moth in apple trees and carefully follow the directions.
It is important that you provide irrigation to the tree where the lawn was removed. The tree developed roots in the lawn area because there was water there to maintain the lawn. Although the pea gravel will serve as a mulch to reduce evaporation of water from the soil, irrigation will be necessary. Water well to moisten the soil to a depth of at least two-to-three feet every two weeks in the summer and once a month in the winter. Insufficient water can cause fruit drop.
Poor pollination due to a deficiency of pollinators (honey bees) could also be a part of your problem. Honey bee colonies have been greatly reduced by mite infestations. This would result in the loss of large numbers of small fruit early in the growing season.
Another factor may be the shade from nearby trees. Apple trees need several hours of direct sunlight each day. If the surrounding trees that are shading the gravel are also shading the tree, the competition for light could be causing the loss of fruit. In addition to competing with the apple tree for light, these trees are also competing for water and nutrients. Competition for light, water, and nutrients may be a more difficult problem to solve, especially if the other trees are on your neighbors’ properties. More frequent irrigation should help if this is the problem.
Finally, there is a percentage of fruit that will drop in the summer every year. This is aggravated by competition from other trees and by the infestation by codling moths.
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Cherry (or peach) tree from pits 8-01
Q. Can I grow a tree from planting cherry and peach pits? How can it be done?
A. The cherry, like all temperate fruit trees, requires a "chilling" period or winter to prepare the seed for growth. The hard shell of the pit does not need to be removed, but the seed should be placed in moist vermiculite or peat moss and stored in the refrigerator for six to eight weeks before planting. Do not let the seed dry before beginning this treatment. Once the seed has been treated by chilling, it may be planted - outside if the weather is already cool, or in a pot in a window or greenhouse. If planted outside, it will experience further chilling and begin growing in the spring. If planted in a pot, it will begin growing in a few weeks. Plant several seeds because it is possible that only a few will grow. In about seven to ten years you may begin eating cherries from your tree. If you graft a part of your seedling onto a mature tree, you can cut several years from the wait. The fruit from your seedling may be tasty, or it may be bitter. Like apples and peaches, this is a plant that will not produce a seedling exactly like the parent.
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Failed cherry crop 5-98
Q. My sweet cherry tree bloomed well this year like the one described in last week’s question. However, I saw no sign of freeze damage in the tree or in surrounding plants. Could something else have caused the problem?
A. Yes, the weather in New Mexico is usually a good choice if there is blame to assign; however, there are other factors to consider as well. Another major factor in fruit development in New Mexico orchards is pollination or the lack of proper pollination. Weather can cause poor pollination if it is cold or rainy during the time of bloom. If it is cold or rainy, the insects which carry pollen from one plant to another may not be active. Rain is usually not a problem in New Mexico when it comes to pollination, but temperature can cause the bees to stay in their hives.
Sweet cherry trees require a pollinator tree to be relatively near. If such a pollinator tree is not nearby, then cherries will be few or none. That is because most sweet cherries cannot be effectively pollinated by pollen from the same variety of cherry tree. For example, if you had only Bing sweet cherries and there were no other cherry varieties nearby, you would have no or few cherries produced. Sour cherries don’t bloom at the same time, so they are not effective pollinators for sweet cherries.
In New Mexico and many other parts of the country there is another factor affecting the pollination of fruit trees and vegetables. That is the lack of pollinator insects due to the death of many bee colonies caused by mites which parasitize the bees. There two major mite problems, the varoa mite and the tracheal mite. Both can cause problems by weakening and killing whole bee colonies, whether the bees are feral, that is wild bees, or "tame" bees in hives.
There are other bees and insects which can provide pollination services. These include the large and fearsome looking bumble bee and many types of smaller, non-colony forming bees. However, bad weather combined with reduced honey bee populations can be a major factor causing poor pollination of cherries, other fruits, and vegetables.
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Fall tree planting 10-99
Q. When in the Fall would be a good time to plant or replant Plum and Cherry trees? I notice that they are beginning to sell them in the stores. Also, how big do they have to be to survive the winter?
A. Now is a good time to be planting trees. So, from now until the ground freezes is a good time to plant the trees. The trees are now going dormant, so don’t expect or try to encourage growth. The trees you buy should be sold in containers, and it may be necessary to "score" or cut any circling roots at the edge of the root ball. Don’t worry about injuring the tree as you do that. Failure to cut circling roots will be more damaging in the long run. Autumn is the time when much tree root growth occurs, so it is actually an excellent time for planting, and new roots will rapidly be formed to replace any which are cut.
If by "replant" you are referring to transplanting trees which have come up in the wrong places, now is also a good time to transplant them. As you dig them up, you will lose a large percentage of the root system, and now is a good time to transplant them as it is a good time for new root growth. As the air temperatures cool, the soil continues to be warm for a while so much of the activity of the tree moves underground and new roots are produced. The larger the tree transplanted, the greater the percentage of roots which are lost. Smaller trees which lose a smaller percentages of their roots are easier to transplant.
As far as size of trees from the nursery, the same rule of thumb applies - smaller trees reestablish in the landscape more easily. However, it is easier to establish large container grown trees than large trees transplanted from another place in the landscape. Another factor to consider is that a tree has a better chance of survival in the ground (if you provide water if the winter is dry) than it does if it remains in a container through the winter. The soil in a container dries more rapidly, and the roots in a container are subject to greater fluctuations in temperature than the roots of trees in the ground.
Be sure to water the tree once every three or four weeks through the winter unless we have sufficient moisture to keep the soil moist to at least the entire depth of the root ball.
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Fig Tree: Starting a new one
Q. Please tell me how to start a fig tree and a new peach tree. They are too big to dig up and transplant. I planted them in the wrong place and have never moved them, so now they are huge. Can I take a cutting and start new trees, or would it just be easier to buy trees?
A. This is a common problem. It is hard to imagine the amount of space needed when planting a little tree. When the trees grow, they are crowded by each other or by structures, and then it is too late to move them.It would be much easier to start with new trees. In the case of the peach, a new tree is really the best recommendation but the fig can be started from a cutting.
To start a new fig tree, take four- to six-inch cuttings (one- to two-year-old wood) from the tree in late winter, well before leaves begin to grow. Treat the base of the cutting with rooting hormones (available at nurseries). It is recommended that the cuttings be held at about 75 degrees in moist wood shavings for 10-14 days to allow the base to form a callus layer. After callusing, place the treated ends into potting soil or in well-prepared garden soil. Roots should begin to develop in a month or so. While figs are relatively easy to start from cuttings, not all cuttings will form roots, so take several cuttings. Leaves may appear without roots forming, but without root development these leaves will soon wilt. However, as roots form, they will maintain any leaves that develop, and the new cutting will be ready to move from pots or the propagation site in the garden by fall (or the next spring). Remember to allow plenty of room for the fig to grow in its new location.
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Fig tree winter protection
Q. A friend asked me to look on the computer for any information regarding what to do for a fig tree in the winter. We live in zone 6. I'm not sure if this tree is in the ground or potted. Any information would be appreciated.
A. I assume you are asking about edible figs, not ornamental figs and will provide an answer appropriate for the edible figs. While figs will grow in New Mexico as far north as Albuquerque, that is pushing their limits. Albuquerque is in hardiness zone 7 as determined from the U.S. Department of Agriculture's hardiness zone map. I am not aware of figs growing further north in New Mexico. However, in a protected courtyard, it is possible that they will grow in colder climates.
In zone 6 a protected location shielding the tree from the coldest weather and where the soil doesn't freeze would increase the chances of the tree's survival. It may freeze to the ground many winters, but if it is a variety that bears on the current season's growth, it will still produce figs. There are other varieties that produce on older growth. These will not produce figs if they freeze to the ground. It is possible to wrap the tree with insulating material after the weather has turned cold and the fig tree has lost its leaves. This must be done with special care. If it warms inside the protection, the tree may begin growing and suffer severe damage in the next cold spell. This protective material must be removed while it is still cold to avoid the situation described above.
The tree will begin to lose dormancy when the weather warms and be very subject to damage once the material is removed if the timing is not good. You must also be prepared to replace the covering quickly if late, extremely cold weather is expected. A potted tree may be easier to grow. Once it is dormant, it can tolerate some freezing and doesn't need light. What must be avoided is extreme swings in temperature and excessive warming. The tree may be stored in a cold garage in which the temperatures range from below freezing to a little above freezing. It will need to be watered as the soil dries but will need little additional care until the weather warms.
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Fruit tree branches break under load
Q. In the past the fruit on my fruit trees has broken the branches of the trees when the trees produced a lot of fruit. What can I do to prevent this?
A. There are several actions you can take, but right now I would recommend that you thin the fruit on your trees. There are several benefits, one of which is that the damage from branch breakage is reduced. Fruit spacing on apples, apricots, and peaches should be approximately four to six inches between fruits. Cherries, plums, and smaller fruits can be allowed to remain closer. The time to do the thinning is while the fruit is still very small.
To thin the fruit, remove some of it - especially at the ends of the branches. Fruit which develops at the end of the branches are more likely to stress the branch than those closer to the trunk where the wood is thicker and the "lever arm" (leverage effect) is less.
When you thin, you also increase your edible yield. This is because, although you have fewer fruits, you also have fewer apple cores and peach pits. With fewer fruit on the tree, each one becomes larger, but the core or pit doesn’t change as much in size, so your edible portion increases while the inedible portion decreases. The larger fruit at the end of the branch can do as much damage as fewer smaller fruit, so be sure that you thin well at the ends of the branches.
Some gardeners thin by hand, others "sweep" the branches with a broom, and others use high pressure water from power washers. Whichever method you choose, minimize the damage you do to the leaves and remaining fruit. Except for the highest elevations and northernmost parts of New Mexico, it is too late to use chemical thinning. Chemical thinning, the use of a substance sprayed onto the very young fruit, is better used in large orchards than in home orchards anyway.
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Fruit trees: how long before fruit? 7-00
Q. I started my plants from a seed, but they have not produced fruit. Some one told me you have to graft them. If this is true how do you do that and what time of year and how big does the plant have to be?
A. The advice you received is not totally correct. Plants grown from seed will usually bear fruit However, there are some factors to consider depending on the type of plants you are growing,. While annual plants will produce fruit the first year from seeds, some fruit trees may not bear fruit for 5 to 15 years after the seed has been planted. Since you spoke of grafting I assume it is fruit trees that you are asking about. Juvenility factors may also delay blossom production in flowering perennials such as amaryllis, lilies, and other such plants.
After a seed germinates some of our fruit trees will first be in a "juvenile" state which is not capable of flowering and bearing fruit, this period of juvenility may last many years. Grafting is a way to circumvent the juvenility phase of the plant. A two year old fruit tree may be grafted and begin bearing fruit two to three years late. To do this it is necessary to graft onto the seedling tree, a scion from a mature fruit bearing tree. Another factor to consider is that most of our fruit trees are heterozygous, that is the genetics in the new plant grown from seed are genes derived from both the "mother" and "father" trees. Such genetics are very complicated and the offspring may bear good or bad fruit. That means that the fruit may be sweet or bitter, large or small. It is interesting to see what develops, but it will most likely not be like the fruit from which the seed were taken. In rare cases, it may be better, but more often it will be worse. Grafting overcomes this problem because the fruit produced by the branch grafted onto the seedling will be exactly like the fruit on the tree from which the branch was taken. There are many good books on grafting available in libraries if you would like to try grafting. Grafting is a skill that must be developed. Success is not often achieved with the first attempt. Practice is essential.
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How much water for fruit tree? 7-99
Q. I planted a semi-dwarf Elberta peach about 6 or 7 years ago. Every year we get about the same number of peaches (25-30). They are good quality. However, the tree has not grown more than a couple of inches since we planted it. It leafs out normally, the branches grow an inch or two and stop growing. I water once a month in the winter, once a week in the spring and fall, and twice a week in the summer. I use a liquid, spray-on fertilizer just before and during its expected growth, yet it doesn’t grow. Please help me and my tree.
A. Because your tree is a semi-dwarf peach, it will grow more slowly that standard-size peaches. The production of fruit also limits its growth. If you would like to see more growth, you might try removing at least half the fruit in May next year. Fertilizer with a high nitrogen analysis will also stimulate vegetative growth (at the expense of fruit production), but don’t apply such fertilizer after mid-July. Applying nitrogen too late may stimulate growth which has not hardened for winter before your first frost.
Your watering schedule seems adequate, or perhaps too often, but your watering frequency should be determined by your soil type. How much water do you apply with each irrigation? It is important to apply water equivalent to about 80% of evaporation-transpiration (ET - water evaporated from a wet surface and transpired through plants). The potential ET rate is determined by measuring water evaporated from a standard evaporation pan. This data is available on the Weather Page of the NMSU/College of Agriculture World Wide Web Page. (This page, http://weather.nmsu.edu, is maintained by Dr. Sammis at NMSU
The quantity of water to apply should be 80% of that reported as evaporated (in inches) times the area of the absorptive root system times the number of days since the last irrigation. The area of the root system is (for your tree) probably a circle with a 5 to 10 foot radius around the tree. The water should be applied over this entire area (except for about a 1 to 2 foot radius next to the trunk). Since only the surface dries quickly, deeper water remains longer, so watering once a week or less should be all that is required. The soil type determines the frequency of irrigation because sandy soils hold less water than clay and should be watered more often. You can determine when to irrigate by probing the soil with a screw driver (long blade) about 3 to 5 feet from the trunk. After withdrawing the screw driver from the soil, feel the blade. If it is dry (not cool), it is time to irrigate. If the blade is cool or you can feel moisture, you can wait to irrigate. Test a few days later. It may take a few weeks for the tree’s root system to adapt to a new irrigation schedule, so change gradually.
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Lemon tree from seed
Q. How can I grow a lemon tree and get lemons from seeds?
A. You can collect the seeds from a lemon that you eat to grow new lemon trees. It is important that you plant them immediately after you take them from the lemon fruit. They will not tolerate drying like our common garden seeds. This is true of many other tropical fruit seeds. If the seeds have dried a little while, they may still germinate, but the chances decrease rapidly with the increase in time that the seeds have been dry. Once you collect the seeds, wash them well to remove sugar that may still cling to the seed coat. The sugar will encourage fungal attack. Fungi may then kill the young plant as the seed germinates. Plant the seeds while still moist in a pot filled with potting soil that has been pasteurized by heat to kill disease organisms.
If the bag has been opened for a while, or if you make your own potting soil from homemade compost, you may want to pasteurize it yourself. You can do this by heating the moistened soil to a temperature of 160 degrees Fahrenheit and holding that temperature for 30 minutes after the center of the soil reaches 160 degrees.
Plant the seeds approximately one-half inch deep in the potting soil, moisten the soil slightly, then cover the top of the pot in which you planted it with plastic wrap to reduce evaporation so that the seed and soil will not rapidly dry out. As the soil begins to dry, add a little water, but be sure the soil does not become soggy. The pot in which you planted the seed should have drainage holes so that surplus water may drain away when you irrigate your seed and later the seedling.
Keep the pot with seeds in a warm location, such as the top of your refrigerator, until the seeds germinate. For this first period light is not necessary, but once the seedlings begin to appear, they will need light. If they are in a dark location, move them to a location which receives several hours of bright light each day. Direct sunlight is not necessary, but bright light is necessary.
An interesting thing about citrus seeds is that you may get several seedlings from each seed. One of these will be from the embryo formed due to pollination in the orchard, but the others will be "apomictic" seedlings which are vegetatively produced. That means that the apomictic seedlings will be exact genetic reproductions of the tree on which the fruit was formed, they are clonal seedlings. The one seedling produced by pollination will not be clonal as it will carry genetic material from the pollen parent (father) as well as the seed parent (mother). In any case, you should have a lemon tree, and it will very likely produce tasty lemons in about 15 years! I thought you would want to know that it will take a long time unless you graft from the seedling to a mature lemon tree. A mature tree may often be purchased at a nursery in the house plant section. There are dwarf house plant lemons from which you may also choose. Grafting may reduce the time for fruit production to only 5 years or so.
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Peach Tree: Starting a new one
Q. Please tell me how to start a fig tree and a new peach tree. They are too big to dig up and transplant. I planted them in the wrong place and have never moved them, so now they are huge. Can I take a cutting and start new trees, or would it just be easier to buy trees?
A. The peach tree can be propagated by starting a new seedling in a pot or in the garden and grafting branches from the old plant onto it. This is much more complicated than starting with a cutting. It is much easier to begin with a new tree from the nursery.
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Pear tree leaves damaged
Q. Enclosed are leaves taken from my pear tree. (They are dry, and blackened around the edges.) When they first appear, the seem to be healthy. Then the edges begin to turn brown. The tree gets adequate water. This problem was first noticed last year and now is occurring again. The tree appears to be healthy otherwise and fruit production is not affected.
A. When observing black leaves on pear trees, it is important to rule out fire blight. The symptoms do not appear to be those of fire blight, so we will rule it out first. That is good. Fire blight is a bacterial disease which is difficult to manage. A common problem observed in trees in New Mexico each spring is blackening of leaves of pear, cottonwood, and many other trees. This can be due to slight frost damage or by wind damage. The frost damage may have occurred on a night in which temperatures at location of most thermometers registered temperatures above freezing; the frost may have been localized to small pockets.
Young leaves in the spring are often very tender and subject to damage from the winds which develop during our warm desert days. Temperatures can rise from very pleasant temperatures to rather warm mid-day temperatures. These warm days following cool nights, when combined with our frequent spring winds, can cause rapid desiccation of the leaves. The leaf margin is the most likely injured part of the leaf. This desiccation can occur even if the soil has adequate moisture because the wind can draw water from the leaves faster than the tree can move it from the soil into the leaves. Very young trees may not exhibit symptoms because they are smaller and closer to the ground and more protected from the wind, and also because they have less distance to move water through the plant to resupply the leaves.
Newly transplanted trees, with limited root systems, and those which have just begun rapid growth after a couple of years establishment following transplanting may be the most likely to show the symptoms. However, under the right conditions this spring wind desiccation injury can occur in larger trees as well. As long as the tree appears to be healthy and fruit production is normal, there should be little to worry about. New Mexico's climate can provide some harsh environmental conditions which cause cosmetic defects in many of our landscape and garden plants. One other problem to consider in New Mexico, but which did not appear to be a problem in the samples sent, is salt damage. Our soils are often salty, containing sodium and other salts, which can accumulate to excess levels in leaves. Older leaves will develop chlorosis, yellowing, while new tender leaves will turn black. Use of poor quality irrigation water, high in dissolved salts, will aggravate the problem unless sufficient water is applied during irrigation to leach excess salts below the root zone of the crops grown. For more information on proper irrigation and other cultural methods to minimize salt problems, contact your local County Extension Service office.
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Pruning – when to prune apple trees?
Q. When should I prune an apple tree? Do I need to put pruning paint on the cut now, or can I wait until spring?
A. Late autumn, after trees are dormant, is a good time to prune most deciduous trees and shrubs. You can prune these trees from fall until the buds begin to swell in the spring. However, remember not to do major pruning on roses or grapes at this time of the year. If the roses have long stems that may be damaged in the winter winds, they may be pruned slightly, but do your major pruning in the spring. They will do best if pruned a month or less before the last expected freeze in the spring. Others that should not be pruned now are spring flowering shrubs such as lilac and forsythia. Their flower buds are now present on the branches and pruning now will remove next spring's flowers.
Regarding the pruning sealer: The Extension Service does not recommend use of pruning sealers. If the tree is pruned properly, there is no need to use the pruning sealer. It is important to prune properly; this will do much more to maintain the health of the tree than the application of pruning sealer products.
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Spraying fruit trees
Q. When should I begin spraying my fruit trees, and what should I use?
A. This question is hard to answer because it gives too little information. What kind of fruit trees? What insect and disease problems have been a problem in the past? Don't apply products unless there is a problem to solve; you may create a real problem if you treat for a nonexistent problem. Is this an orchard or a few backyard trees? I can safely assume from the address that this is a backyard "orchard" with a few trees. I will have to guess at the answers for the other questions. The fruit trees which have the greatest problems in New Mexico tend to be apples with codling moth or powdery mildew problems, cherry trees with peach tree borer or cherry fruit flies, or peaches and other stone fruits with peach tree borer problems. While there are other problems encountered in New Mexico, these are much more common than others.
If you have different problems, be sure to contact your local Cooperative Extension Service office or Master Gardeners for assistance in diagnosing the problem. Many local nurseries may also be able to help. Regarding apples, codling moth larvae are the worms in the apples. Use of a horticultural oil as a dormant spray now can help reduce the problem in the summer but will probably not eliminate the worms from the apples. A dormant spray will also help reduce other insect problems you will encounter in the summer. For homeowners, there are several products which must be used through the summer to prevent the worms in the apples. Some of these are organic insecticide materials, others are those called synthetic insecticides such as Diazinon(c) which has proven effective at codling moth control.
Whichever product you choose, it may be necessary to reapply the product several times through the summer, some as often as every ten days to two weeks. Be sure to buy a product intended for use on the plants you have and intended for management of the problem you have identified. If powdery mildew is a problem, there are products labeled for use on apples which may be used if the problem is severe enough to require treatment. Cherries don't get codling moths, but they are subject to fruit flies. Here in New Mexico the problem is the Western Cherry Fruit Fly. Not the kind of thing you want to find in a cherry after eating a handful without checking first. Actually, you can probably eat them without harm to yourself as long as you don't see them. Personally, however, once I have seen one, the cherries don't taste good any more.
A dormant spray will not be helpful in solving this problem. Pesticides such as Malathion(c), Diazinon(c), or Sevin applied to the ground under the trees and to the leaves as the cherries approach full size can help. There are also some cultural techniques such as placing a sheet of clear plastic on the soil under the tree from the time the fruit begins to enlarge until after harvest. The reason for treating the soil with pesticides or plastic covering is that the fly pupae (cocoons) mature in the soil under the tree. They emerge from the soil as adult flies when the fruit is maturing. The female flies lay their eggs in the nearly ripe fruit where the maggots develop and destroy your appetite.
Treating the soil under the tree will probably not be sufficient since you live in town with neighbors nearby whose trees are untreated. The adults can fly a considerable distance to get to your tree. Here in New Mexico the flies can receive quite an assist from the wind if it blows the correct direction. Again, choose your control products after carefully reading the label, then follow the label directions when using it. The peach tree borer attacks all of our fruiting and ornamental stone fruit trees, those trees whose fruit have a pit such as cherries, almonds, apricots, and peaches. Their larvae borer into the tree at the ground level or just below the soil surface. If the tree is young or heavily infested, the borers can quickly kill the tree. Often they attack and weaken the tree, and subsequent attacks over the years result in the decline and death of the tree. The frustrating part is the tree will often die with a bumper crop of fruit shriveling on the tree.
The chemical products for controlling peach tree borer are becoming less numerous. Dursban(c) is still labeled as a preventive spray to be applied at the base of the tree in late spring. It only prevents successful infestation by new peach tree borer larvae; it does not kill those already under the bark. Parasitic nematodes have proven to be a reasonably effective biological control measure with the benefit of "search and destroy" capabilities. These tiny round worms, if applied around the base of the tree, are able to travel a short distance in search of the borer larvae which they enter and kill. In all cases, it is essential that you properly identify the pest problem and choose a management method appropriate for that problem on the specific crop you are treating. Then read and follow the directions on any product whether an organic pesticide or synthetic.
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Sugar maple tree
Q. In May of this year I had 3 sugar maple trees (20-25 ft) transplanted into my yard. The leaves came out just fine at first; however, now they appear to be yellowing (they have a greenish yellow hue) and some are even browning and falling. I am watering them frequently as we have had little rain since May, but still they are not greening back up. Is there any nutrient/fertilizer I could use. Also I have noticed some brown spots on most of the leaves...is this some kind of disease? Any help you can suggest would be appreciated.
A. When large trees are transplanted, much of their root system (up to 90 percent) is left behind. Until a new root system can be generated, the plants will suffer from desiccation stress and transplant shock. The process of establishing a new, adequate, root system can sometimes take several years and is dependent upon the size of the transplanted tree as well as soil moisture. I suspect you are seeing the effects of transplant shock as the limited root system cannot provide sufficient water and nutrients to the leaves.
Fertilization during the establishment period is not necessary in most soils. There should be sufficient nutrients in all but the sandiest soils for the first year or two of growth. Excessive fertilization, which stimulates growth of stems and leaves, prolongs the time in which the root system is inadequate to support the top. A little fertilization after the second year will help, but be careful not to apply too much nitrogen. Pruning to "bs is also not advised. Just prune those parts which weaken and die. Too much pruning will reduce the number of leaves which are important in providing food necessary for root development. Since there are diseases and insects which could also contribute to the symptoms you have described, it would be wise to consult with local horticulturists who are familiar with your local conditions and horticultural problems. Check with local nurseries, the Cooperative Extension Service, or Master Gardeners.
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Tomato tree?
Q. Someone told me about a tomato tree. Is there such a tree as this?
A. The tomato tree or tree tomato is a plant in the tomato family but is not a tomato. Its scientific name is Cyphomandra betacea. The genus Cyphomandra includes about 29 other species, but only the species C. betacea is commonly grown for its fruit. The tomato tree requires warm temperatures since it is from the tropics. It is native to Peru. Outside the tropics, it must be grown in a greenhouse. It takes one and one-half to two years to become large enough to produce fruit. It needs a deep, fertile soil. However, I have seen it growing in a large pot in a greenhouse. In a pot, it might not reach its maximum potential size of over 10 feet. The fruit is orange-red, egg shaped, and about two inches long. The fruit may be eaten uncooked but is most commonly stewed or made into jelly. My reference did not describe its flavor. I have noticed that the plant has an unpleasant odor when you bruise or break the leaves and stems. Many plants in the Solanaceae, or tomato family, contain poisons in the parts of the plant which are not eaten. So, if you decide to grow the plant, eat only the fruit. I found no information about poisons, but caution is wise.
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When to prune cherry tree 11-99
Q. What season do you prune cherry trees?
A. Cherry trees are best pruned during the dormant season; that is, from the time the leaves fall until the buds begin to swell and "show color" in the spring. This is true for most other deciduous trees. For some flowering trees and shrubs, pruning at this time will reduce the production of blossoms, but this is the least damaging time to prune. As long as all the twigs aren’t pruned from the tree, there will be flowers.
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Why cherries all dropped off tree
Q. My cherry tree blossomed well and began to develop a bumper crop of small cherries. Then when the weather warmed, and most of the cherries dried up and dropped from the tree. What happened?
A. I can only guess at the source of the problem. One likely cause is a late, spotty frost. This did happen in Albuquerque this spring. Some people still have a bumper cherry crop and others describe what you have experienced. Many of our trees seem to exhibit some minor frost damage. This probably occurred after a period of warm weather when the plants had begun to grow. Through the winter the buds and bark of the trees had been quite hardy, but to grow they lost this hardiness. Our quick drop to moderately cold temperatures could then cause injury. Because of our topography, slopes and hills, pockets of slightly colder air formed in some areas. While some areas were just warm enough not to cause damage, these pockets of cold air were just cold enough to damage the flowers. The damage was so slight that while the weather remained cool, the damage was not evident. When the weather warmed and the demand for water increased, the damage became apparent and the cherries dropped.
There are other things which could also have contributed to the problem you described. Watch for evidence of peach tree borer (yes, even in cherries) at the base of the tree. You will observe a dark sawdust material and a gummy exudation. If this is observed, ask your local nursery or Cooperative Extension Service office for a product labeled for peach tree borer control in cherry trees.
Another problem to watch for is crown gall. Crown gall is a disorder caused by bacteria that enters through wounds and causes the formation of a gall, or tumor, on the base of the tree, branches, and underground roots. It is observed as a crusty, bark-covered swelling. If the roots are affected, you will often see suckers (stems) emerging from the ground above the roots where they formed. There is no cure for this disorder. Just care for the tree as long as it is attractive and productive. Once it is no longer worth keeping, replace it with another tree, but select one that is resistant to crown gall. That means you will not plant a cherry tree at the same site.
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Cherry shortage 3-03
Q. I have a miniature Bing cherry tree. I planted it 3-4 years ago. When it blooms, it has plenty of flowers but just after the cherries start to form, they dry off leaving no more than 10-13 cherries to pick. What could be the problem?
A. The sweet cherry tree requires pollination to set fruit. In the last several years, there has been a shortage of honeybees. There have been a couple of mite pests that have killed many feral (wild) honeybee hives. If there are not enough bees active in the area, the cherries will not be pollinated.
Weather can also prevent pollination. If the weather turns cool when the cherries are pollinating, bees will be less active, even if they have survived the mites.
Finally, there should be another variety of sweet cherry nearby from which bees may bring pollen. A sweet cherry variety does not successfully pollinate itself. It must receive pollen from the nearby different variety of sweet cherry.
Any of these may explain your problem. First, look to see if bees are active in the tree when it blooms. If so, notice the weather. And finally, look around to see if there are other pollinator varieties nearby. If not, you may need to plant a different variety of sweet cherry in your own yard.
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Growing lemon trees indoors 4-03
Q. I am very interested in growing a lemon tree. I understand that a lemon tree will freeze in New Mexico, so is it possible for me to grow a lemon tree indoors?
A. It is possible to grow lemons in New Mexico, but it is difficult. You are correct that the tree will freeze in most areas of New Mexico in the winter but will do well outdoors in the summer. Some nurseries sell dwarf varieties that may be grown as container plants. These container-suitable varieties are the ones to try. As the tree becomes larger and the container becomes heavier, it may be wise to get a wheeled "dolly" to place under the container so you can easily move it indoors in the winter and outdoors in the summer.
While it is possible to keep the tree in a garage during the winter in many parts of New Mexico, a sunny location is better. For proper color development of citrus (including lemons), cool conditions are necessary. For that reason, its winter location should be cool. Bright light is also important during the winter. During the summer, a partly shady location is recommended. Protection from hot, drying winds will also help.
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Yellow leaves on Bradford pear trees 5-03
Q. I have a problem with a Bradford pear tree in Las Cruces. The leaves are quite yellow and eventually turn brown at the tips of the branches. There are no "shepherd's crook" shaped branches or visible cankers to indicate fire blight. I've talked to two Master Gardeners and both were perplexed. I have noticed several other Bradford pear trees with the same sort of problem, notably the row along Terrace Drive behind Memorial Medical Center. My tree has had these symptoms for three years. It does put on new growth every year. Could this be a chemical deficiency or possibly a fungus?
A. The fact that you have already talked to two Master Gardeners and they were perplexed gives me reason to be cautious in answering without seeing the tree. One possibility could be iron deficiency. Iron deficiency can cause the chlorosis (yellowing) symptoms you have described. If the chlorosis is not too severe, the yellow leaves will have green veins. In more severe cases, the leaves will be quite yellow and will begin to turn brown and die. Try spraying a solution of iron sulfate on the leaves to see if you get a development of green in the leaves. If you see green spots where the iron sulfate solution collected on the leaf, this is a good indication that iron deficiency is the problem. If this is the case, use an iron chelate or iron sulfate application to the soil. Such treatments are most effective before mid-summer.
If iron treatment doesn't help, you might try applying a micronutrient fertilizer to the soil at the dripline of the tree. There are other mineral deficiencies that can cause yellowing and browning.
Another possibility is salt accumulation in the root zone. These salts may have occurred naturally in the soil or may have resulted from irrigation with salty water. Some salts can interfere with mineral uptake causing the symptoms you described. A soil test can help determine if salt is the problem.
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