Why Is My Pine Tree So Sparse?

Q. Why does my one pine tree seem so sparse and inadequate?  I purchased four Mondale pines and treat them all equally. But the one shown in the left picture looks so scrawny.  The other one shown looks healthy and appears to be robust.  Any thoughts on that? 

Aleppo pine blight

A. The usual reason for a pine tree being sparse and not full is that it is not receiving the same treatment as the others. I have to assume the picture you are painting for me with words is the same one that I am seeing and understanding.

            When you say the tree is ”sparse or inadequate” this, to me, means that there are far fewer needles along the branches of this tree compared to the branches of other trees. Pine trees generally maintain needles on their branches until the wood gets to be three to five years old and then the needles are dropped from this older wood. This older wood is needle-less except for other small branches growing from it that are less than five years old.

            The reason for thinning is that there is not enough young growth covering the entire tree so that needles are lost at a higher rate than they are being replaced. If you were to look at the growth of the youngest branches you can actually see each year’s growth for several seasons and count back several years of growth on one branch. This gives you an idea of how much growth a tree is putting on each year so that it can be compared to the other trees.

            So bottom line for “thinning” is that the tree is not growing fast enough (or putting on enough new growth). I know that this seems a bit simplified but we have to start at the simplest point if we are going to try and figure it out. Reasons for thinning include water, fertilizer, damage to the tree, or disease or insects. So let’s follow the keep it simple rule first and handle the most frequent and common reasons. Once we have eliminated these then we can move on to the more “exotic” answers.

Pine tree dieback due to shading

            By far the most common reason is differences in the amount of applied water or water available to the plant. So when you say you treat them the same it does not necessarily mean these treatments are all reaching the trees equally. But if there is inadequate water two things will happen; the tree will put on less growth and the needles will be partially brown from the tips.

            The first thing to do is to check and make sure that whatever is delivering water to the tree is not plugged. Secondly make sure that water applied to the base of the tree is not running off the surface to some other location. Just because water is applied to a tree does not mean it is getting to the roots.

            Remember that as these trees get bigger their demand for water increases. The increase is not a simple few gallons per year but rather the increase is much more dramatic because trees are three dimensional in their water use unlike a lawn. A lawn doubles in size then its water use doubles. When a tree doubles in size its need for water is probably more than double.



Pine tree thinning due to lack of water

            One tree showing signs of water stress might be an indicator that in the next few years the others may also show the same signs. What you are seeing is a snapshot in time and may not indicate what will happen in future years if all things remain the same. As a precaution, I would start to increase your water to the trees and supplement the thin tree with some water from a hose to see if there is a difference.

            The next most common reason is that the roots of the tree in the container never fully established into the surrounding soil after planting. This can be because the tree was too old for the container and the roots started circling inside the container.

            It can also be because the tree was not firmly staked at the time of planting so the root system doesn’t move. You should be able to push on the trunk and NOT see any movement of soil at the base of the trunk.



Mondale pine dieback due to unknown,
nonpathological problem

            If you see movement of soil then the tree most likely never successfully transplanted from the container into the hole. If the tree moves easily in the soil then it is difficult for them to ever get established and most likely never will if it has been five years and they haven’t.

            Trees need to be firmly staked when planted to immobilize their roots and give them a chance to get established in the amended soil surrounding the container roots. If this is the case you are better off getting rid of it and replanting.

            A third possibility can be that it was planted too deep. If planted too deep the tree can die fairly quickly in one season or linger for several years due to damage to the trunk from disease organisms.

            Pull the soil away from the trunk and see how deep the first roots are. They should be no more than perhaps half an inch from the soil surface. Sometimes soil can fall back into the hole after planting, the plant can sink in the hole (this is why I tell people not to dig the hole deep but rather wide) or mulch can be pushed up against the trunk when it is young causing a disease called “collar rot” to develop.



Pine tree damage due to weed killer ie
herbicide (dicamba)

            The next most common reason is damage to the roots or trunk. This will be far less likely than a watering problem but much easier to identify. This can be physical damage like construction, damage from chemicals like salts or weed killers, insect or diseases like collar rot.

            If it is insects or diseases it is most likely to affect a few branches rather than the entire tree unless the damage from insects or diseases occurred to the roots or trunk. If damage is to the roots or trunk then thinning may also occur and look very similar to a lack of water.

            So inspect the trunk for loose or damaged bark. This can include damage from equipment like mowers or line trimmers if it is in a lawn area or surrounded by other plants. Check and make sure the tree is firmly anchored in the soil after this number of years.

            If none of this seems to pan out lets follow the keep it simple rule for now and increase your water during the spring and summer months.

            After looking at your pictures again another reason occurred to me. That is shade. If the tree is being shaded by other plants and not receiving enough light (at least six hours a day) then these branches in the shade can drop their needles. If this is the case then some pruning to allow more light will help.

Should I wrap the Trunks of My Date Palms?

Q. I live in Pahrump and last winter we had a cold spell that turned the fronds on most of my Canary Palms brown and one of them is still recovering. How can I protect them from the cold the rest of the winter? A few neighbors have wrapped theirs where the fronds meet the trunk with burlap. Will this help?

A. There really is no magic way to do it. Many palm trees generate their new growth in the coming and future years from the terminal buds located at the tip of the trunk. The bud is usually good to about 10F for short periods of time. If cold kills the terminal bud the tree will eventually die because it cannot continue its growth without that terminal bud. Damage can also occur to the trunk from freezing temperatures so wrapping the trunk or wrapping some lights around the trunk might help if there is wind and low temperatures.

            Remember that cold damage is measured in how low the temperature gets combined with the amount of time it stays at these temperatures. Wind makes it worse. Then you have to figure the time of year as well.

            Extreme cold is usually more damaging in late fall and early spring than mid-winter. Winter damage to palms may not show up right after the cold temperatures. In some cases the extent of the damage may linger for years. Not very encouraging but I hope this helps.

My Turnips Taste Very Bitter

Q. I planted turnips from six-packs in September.  I harvested two beautiful turnips but their flavor was terrible, approaching inedible. They were very bitter. What may have happened?

A. The timing for planting sounds okay but heat will do that to turnips and many other root crops. Turnips have a higher germination threshold temperature, about 60F, and so have to go in a bit earlier in the fall than beets, parsnips or rutabagas and later in the spring. Also, a lack of water would too but if they are a good size and shape then I doubt it is a water problem.

            Another thing to note is that turnips, like rutabagas, can contain a bitterness that some people find intolerable. This is an inherited trait in people so that some people will taste the bitterness while others may not. You may be one of these people. Also, you might try boiling them first, throw the water out half way through boiling and replace it. This may help remove bitterness.

            I would switch to a different variety or grow kohlrabi instead which I find much more enjoyable and easier to grow. Make sure your soil has been prepared with plenty of compost and phosphorus prior to planting. Make sure they get adequate water and I would even mulch them with some straw after they emerge if the temperatures are still warm.

I got an update. Turnips harvested later were not bitter so sounds like they were planted a bit too early and got hit with some high temperatures.

When Should I Pick Oranges in Las Vegas?

Q. I have a tree loaded with oranges but I am not sure when to pick them. I read in the paper today about the Meyer lemon tree and you said to pick them now. Should I pick my Washington navel orange now?

A. Since this is not a commercial growing area for oranges we have to take our best guess at the time for picking. It is not the same for Myers lemon and different oranges will be ready at different times. The problem here is if you wait to pick through the winter, we may get a hard freeze and you could lose the fruit.

            Washington navel orange fruit mature at the Christmas season in California. In hot hot tropical climates the fruit may never turn orange. In cooler climates the fruit turn orange when they mature. If it is close to Christmas and the fruit is orange, harvest it. Use a shears and leave a small nib or piece of stem attached to the fruit if you plan on keeping them for any length of time. If the stem is pulled from the fruit, it leaves a fresh wound where disease organisms can enter and cause early rotting. Pulling them is okay if you are going to use them right away, otherwise cut the stem.

            By the way, if you are going to juice this particular orange then remove the peel first or it may be bitter.

When Should I Cut My Grape Vines Back?

Q. When should I cut my grape vines back?  They're on a trellis, and are 1 year old.  During the summer they spread out very well, and produced several large groups of table grapes.

A. I would wait until late February or early March to prune them. We still have some potentially difficult times to go through this winter for grapes. Cutting them early may result in a loss of bud wood and fruit production.

            When pruning you will cut back this past years growth (it will be a different color) so that only one or two buds remain. I prefer two. Also I usually prune it back so that ten or twelve buds remain if I do it early. Then just before bud swelling in the spring (like about early March) I cut then spurs back to two buds. This way if there is dieback during the winter I won't lose the fruit producing spur.

Privet Turned Brown With Cold Weather. Is it Dead?

Q. My privet hedges turned a copper brown color.  I have three in a row on one side that are really brown while the hedge on the far right still has a substantial amount of green but is starting to get spots.  Not sure what to do to save them. Pictures are attached.

A. These pictures look like possibly cold damage. It could be more than this but I want you to do this to find out. Walk over to the privets and start bending some branches just below where they were pruned. If they are still soft and supple and bend easily without breaking then it is most likely cold damage that caused leaf death.

            If they are supple and bend, don't do anything. They will leaf out again this spring as temperatures begin to warm or you may see them leaf out sooner than that.

            If they all are snapping when you bend them, then there is severe dieback. It is still possible the dieback is due to cold weather this past November. Cold temperatures are very damaging during the early winter if the plants were caught unexpectedly by sudden drops in temperature.

            There was really nothing that you could have done to prevent this. It is the luck of the draw sometimes. However, if there was severe dieback you should have healthy stems closer to the ground. I would wait until late February or March and see where the new growth comes from. I would then cut the dead growth slightly below this new growth.

            Check and make sure they were getting water this winter. Turn your station on and look for water coming out of your irrigation emitters. If there was blockage and you didn't notice, it's possible they could die back from a lack of water. My best hunch, however, is cold damage.

My Pomegranates Were Spoiled When I Harvested Them

Q. I have a single, four year old pomegranate tree in Las Vegas.  The tree produced excellent fruit the first three years.  This year the fruit was spoiled as they came off the tree.  The tree appeared normal.  Looking at the fruit, it wasn't evident if it was infested with a bug or a disease.  Would you have any suggestions on what caused it? 

Adults

A. The most likely reason would be an insect called the leaf footed plant bug. They will infest pomegranates, almonds and pistachios most frequently. Their feeding can cause small holes in the outside of the fruit or nut.

            This wound can open the fruit for infection by disease and possibly cause a nut not to develop inside the shell causing what we called blanks, or no nut, to develop. You will see these insects overwintering on your fruit trees or nearby landscape trees as well.

Adults and nymphs

            These are nefarious denizens of the worst kind and seem to have no value except to breed more of the same. I would recommend spraying your fruit and nut trees with dormant oil twice during the winter and follow this a few days later with an insecticidal soap.

            I have seen most of these adults overwintering on the stems and trunks of trees, usually in the sunlight because of the heat they can get. I hope this helps.

White Leaves on Sage Probably Cold Damage But Dont Dry It At Such a High Temperature!

Q. I have a large pot of sage growing on the protected side of my house (north) where all my citrus and other herbs have done well.  I notice that when the weather cools, the sage leaves turn a whitish color.  I collected some for sage dressing, but I didn’t bother using the white leaves, just the green ones.  Is this a natural occurrence during cold weather?  Would those leaves have been okay to use? 

            I dry the good leaves in the oven at 225 degrees for about 1 hour, leave them out in the house to get thoroughly dry for a day or so, then crush them in a coffee grinder.  Works great for my use in the kitchen, especially for sage dressing.  

A. This white discoloration is probably some damage to the leaves due to cold. You are right, don’t use them.

            However, drying at 225F is far too high. This should be done at temperatures between 95 and about 125F. There is a lot of damage done to the herbs at high temperatures, particularly above 140F.

            Our weather and climate is perfect for drying herbs without the use of extra heat. It will take longer than one hour but the quality will be much, much better. Cut the stems of those with flower buds just starting to form. Hang these bunches in the open air and not in intense sunlight for 1 week to dry.

            If this is too slow for you, use a cookie sheet and put in the oven at the lowest temperature that provides heat. Bottom line, do not use excessive heat and keep them out of intense sunlight while drying. Hope this helps.

Don't Overdue It With Ashes from Your Fireplace in the Garden

Q. I've enjoyed your articles in the LVRJ over the years. I Love my backyard garden here on Sunrise Mountain but it's been a challenge compared to growing a garden on the Island of Maui.  I would like to augment my garden soil with the wood ashes from my fireplace. Would that be good for the garden soil? 

A. If these ashes are from plants then there should be no problem incorporating some of it. Much of this has to do with the volume that you want to add. Small volumes of this distributed over a larger area will be no problem as it will be high in some nutrients. One ton of wood ash has about 15 lbs of phosphorus and 50 lbs of potassium but it is strongly alkaline which we don't need. If this ash is coming from plastics or other manufactured products then I would not use it.

Sour Tangerine May Not Be a Tangerine

Sour orange rootstock that took over a Navel Orange tree

Q. I have a dwarf tangerine in a container that gives lots of fruit but it is sour. Why?

A. Sugar content is developed over time as fruit matures. When the fruit is immature it usually has higher acidity and low sugar content. As the fruit matures the acidity drops, and sugar content climbs. Be sure to wait for full color development in the fruit and it should be at its highest sugar content.

            Tangerine is sometimes grafted onto sour orange rootstock. If the tangerine part of the plant dies, the sour orange rootstock will replace it producing beautiful fruit but very sour and it will never become sweet. If this is the case, and this happens a lot in Las Vegas due to our winter freezes, dig it out and replace it.

What To Do to Fruit Trees in December and January

Todo Lists for December and January

Pruning: lower the heights of fruit trees. Lower the heights of fruit trees if you want to do most of your tree management without a ladder. Lowering the height of your fruit tree to a pruned height of 6 1/2 feet will allow you to prune, spray and harvest while standing on the ground. Most full sized fruit trees can be kept to this height through judicious pruning methods. Apples should be grown on a semi-dwarfing rootstock.

Pruning: begin pruning for production. Each type of fruit tree is pruned differently. You must know where your fruit is being produced on the tree that you are pruning. Delay pruning grapes until late February.

Mulch. Use organic mulch in the Orchard or around fruit trees. This is not the same as bark mulch which is inferior to wood mulch. Wood mulch can be kept to a depth of 4 to 8 inches around fruit trees. On younger trees, keep wood mulch 12 inches away from the trunks until they are 6 to 8 years old. Green waste from pruned and chipped ornamental trees makes an excellent mulch. Avoid using trees such as Mesquite with their large thorns and palm trees which decompose very slowly. Organic mulches such as wood mulch return nutrients to the soil, increase microbial activity, retain moisture around the plant roots, reduce weed problems and help keep the soil cool.

Four year old trees with wood mulch. Keep the mulch
six inches from the trunk on young trees.

 Irrigate fruit trees deeply every 10 days. After leaf drop, irrigations can be applied every 10 days to two weeks if you have a surface mulch applied to the soil. Sandy soils may require irrigations weekly to every 10 days. Heavier soils may require an irrigation every two weeks.

Borer control. This time of year concentrate on removing borer damage from fruit trees. Look for borer damage on the upper surfaces of limbs, particularly of peach, nectarine and an apricot. Using a sharp, sterilized knife remove the damaged wood from these areas. Be sure to cut all the way down to fresh wood when removing damaged wood. Let the tree heal by itself. Do not apply pruning paint but you could apply whitewash.

That is one of the flatheaded borers.

Dormant oil application. Dormant oil is an insecticide made from petroleum products used in organic production. The oil itself is not toxic but spraying it on the limbs and trunk of fruit trees helps to suffocate overwintering, usually soft bodied, insects that are pests of tree fruits. Usually to applications are made during the winter months.

Weed control. Weeds that are living close to your fruit trees provide homes for overwintering insects. Once your trees begin growing in the spring, these insects move from weeds to your trees. Keep in areas near your fruit trees without weeds.

Using a backpack sprayer to apply whitewash. Clean
thoroughly when done!

Renew whitewash on fruit trees if needed. Whitewash provides a light colored covering to the outside of the bark of the tree and its limbs. It is particularly important in reducing sun damage to fruit trees due to our high light intensities. Whitewash can be made by diluting white latex paint with an equal amount of water or more. Dilute the white latex paint so that it will color exposed areas of the tree white and reduce sunburn. Reducing the sunburn will reduce the damage from borers.

Pull wood mulch away from the trunks of young trees about a foot. Wood mulch that gathers around the trunks of small trees can damage them.

Remove any stakes from trees planted early in the year. Fruit trees that are planted correctly and are not overgrown in their containers will need staking for only one season. If your trees have not become established after one season, there is a problem.

Limb spreaders easily seen in the winter time

Remove limb spreaders that were used earlier in the year. Limbs spreaders are used to increase a limbs angle of attachment to the trunk of the tree. Ideally, this should be a 45° angle. Limbs spreaders can be applied to the tree now but there is less danger of breakage in larger limbs when the sap is flowing in March. Ideally they should be applied when the limbs are one to two years old.

 Fertilize fruit trees. Fruit trees respond nicely to fertilizers with moderate amounts of nitrogen, high phosphorus and moderate to high potassium. Do not apply them earlier than January. Mineral fertilizers can be granular or in the form of stakes. Organic fertilizers are preferred but can be slower acting. Apply fertilizers where water is delivered to the fruit tree. Keep all fertilizers 12 inches away from the trunk to prevent damage to the tree. An iron chelate, preferably with the chelate in the form of EDDHA, should be applied to the same area, watered in and covered with mulch.

Irrigation system should be checked for plugging, broken lines and runoff.

My Shrubs Growing In Rock Mulch Turned Brown in November

Q. I now water once a week but my shrubs are looking like they might in the hottest part of the summer. Leaves look dry, burnt and falling off. My average shrub is about 3'x3' and receives 3-4 gallons per week week based on my emitters and time on. Did I cut back to much ? What should I do to try to revive them ?

A. Your watering sounds very appropriate and probably what I would have scheduled as well. You have to make sure, however, that the water which is scheduled to be delivered to your plants is actually getting there. Make sure you check for plugged emitters when the system is on. You should have a filter on your drip system even if you are on city water.

             It could be several possibilities. I have to walk through them with you because I don't know much about their previous history. For me, it looks like possibly watering, possibly collar rot at the base of the trunk where the rock mulch sits against the stem, it could be very low temperature damage as possibilities. If there were some very low temperatures just prior to that than this could be just that. If there were no low temperatures than most likely it is not. Then we have to look at watering issues including the rock against the trunk.

First determine whether the plant is dead or not. Bend some branches and see if they snap. If they are still supple and just have damaged leaves then it is a temporary setback and they will regrow and set new leaves in the spring. If they snap when you bend them, it may be dead. You will have to pull it anyway so start bending the branches and see how much of the plant is dead. If the amount is sizable, remove it. When you remove it look at the trunk where the rock mulch was resting against it.

Use a knife or your thumbnail and scrape the bark away from the trunk starting about an inch above where the rock mulch sat and down along the stem to the roots. Look to see if there appears to be a dark area or rotten area in the trunk or bark around the rock mulch line. If there is, then it is collar rot. Make sure on any new shrubs that rock mulch does not lay against the trunk or, in some cases, the plant was not planted too deeply. It should have been planted the same depth as it was growing in the nursery container. Nurseries don't have many plants this time of year because they are trying to reduce their inventories. You can look for a replacement plant but chances are you may not find one that you like until next spring when it gets warm. I hope this helps.

Hobby Greenhouses a Special Challenge in the Hot Desert

Q. My helpful husband gave me a 6 x 6 foot greenhouse for Christmas and I'm wondering what in the world I can do with it here in Las Vegas. I am thinking that I can get a head start on growing seedlings and things like that, but during the summer months, it will probably be a storage area since it's so hot here.  I have it located on concrete on the southwest side of my house, and unfortunately there is no other place for it. Also, maybe I can extend the season into winter months? Any information would be great.

A. That was very thoughtful of your husband. As you have probably already figured out, greenhouses can be tough to manage in our climate. But it can be done. You have one thing going for you. You have a greenhouse. What you don't have going for you is that size and its location.

            Small greenhouses are difficult to manage in this climate because they heat up so rapidly. By modifying your greenhouse you may only have to shut it down for two or three months during the summer.

Generally speaking in hot climates with lots of sunshine, tall greenhouses are better than short greenhouses. Anything you can do to make the greenhouse taller is a good thing. The heat accumulates toward the top of the greenhouse. As the heat builds it puts heat on the crops growing lower. The taller the greenhouse, the easier it is to keep the heat off of the plants.

That Southwest exposure is also tough in the summer but would be nice in the winter.

            During the summer the sun is nearly overhead and in the winter it is at a low enough angle that it mostly comes in through the side walls. You might want to consider orienting your greenhouse so that the door is on the East or North side.

            Next, I would put some shade cloth on the roof or paint the roof with white latex paint to reduce your solar load. There is some bamboo fencing that is quite reasonable that you might consider placing over the roof to create some shade during the summer months.

            These are all options. I would probably look at the bamboo fencing first since you can kind of adjust it by putting more or less of it on the roof. These should be done on the outside of the roof, not the inside.

            If it's possible, you might consider putting a couple of vents in the roof that you can open or that will automatically open for you if there is too much heat in the greenhouse. This will allow some of the heat that accumulates at the top of the house to exit and will help reduce the heat load somewhat. It will not cure the problem but it will reduce the problem.

            You might also consider a small swamp cooler that draws air from the outside. Put it on the cooler north or east side if possible. It is also important that the greenhouse is not sitting in a rock landscape.

            If it is surrounded by rock, it will compound your problem. About the most you will be able to drop the temperature from that little swamp cooler is going to be about a 20° difference from the outside air temperature.

            Another way to drop the temperature is to replace one wall, or build into the wall, a pad system similar to commercial greenhouses. This uses recirculating water just like a swamp cooler but the pad is built right into one of the side walls.

            On the opposing wall is a fan that pulls air through the wet pad cooling the inside of the house. If the pad is 4 to 6 inches thick, it could cool the house significantly provided you reduce sunlight entering through the roof.

Getting Christmas Cactus to Bloom Requires Only Natural Light

Q. How do I get my Christmas cactus to bloom? I was given a 9" pot back in November, kept it indoors with plenty of light, only to find out that it's supposed to be in the dark for 14 hours a day. I started that 3 weeks ago, been watering once a week, gave it cacti food twice, but no blooms.

A. The Christmas cactus is a true cactus and nearly identical to the Thanksgiving cactus. These cacti have slightly different bloom times so they get the names Christmas and Thanksgiving cactus because of their bloom times.

            The amount of light (actually it's amount of darkness) will typically get them to bloom if all the light they receive is natural daylight. It's when they receive extra light inside the home that it can break this rhythm of flowering and cause them not to flower at this time of year.

            These cacti bloom when the nighttime darkness approaches what we get a minimum of 12 hours of darkness. So if they are growing inside they need to be covered so they receive no light from artificial sources. Once covered they will bloom if they remain covered, religiously, for six weeks . They also respond to cool temperatures. So placing them in a colder location in the dark also will help them to bloom.

            Christmas cactus is what we call an epiphytic cactus which means it does not grow in the soil in the wild but on the surface of other plants such as trees. We can however put them in containers and grow them in containers with soils amended with lots of truce one compost, similar to what they would find growing on the surface of a limb in the tropics. This is much like orchids and bromeliads. These cacti can be grown outside here on the northern or eastern exposure in a well amended soil or in containers but you must bring them in if there is any chance of freezing temperatures.

Plant Winter Vegetables Now, Its Not Too Late

Plant lettuce, peas, cabbage (transplants), cauliflower (transplants), carrots, radishes and spinach. These vegetables can germinate and handle lower soil temperatures in the warmer parts of the garden (45F soil temperatures for germination). Prepare the soil by loosening it and applying a starter fertilizer high in phosphorus. Cover the seeds with a dark topdressing to help warm the soil. Activated carbon works great for transferring heat to the soil.

Orchard Calendar: December

Lowering the height of fruit trees

Pruning: lower the heights of fruit trees. Lower the heights of fruit trees if you want to do most of your tree management without a ladder. Lowering the height of your fruit tree to a pruned height of 6 1/2 feet will allow you to prune, spray and harvest while standing on the ground. Most full sized fruit trees can be kept to this height through judicious pruning methods. Apples should be grown on a semi-dwarfing rootstock.


 Pruning: begin pruning for production. Each type of fruit tree is pruned differently. You must know where your fruit is being produced on the tree that you are pruning.

4 to 8 inches of mulch on the orchard
floor

Mulch. Use organic mulch in the Orchard or around fruit trees. This is not the same as bark mulch which is inferior to wood mulch. Wood mulch can be kept to a depth of 4 to 8 inches around fruit trees. On younger trees, keep wood mulch 12 inches away from the trunks until they are 6 to 8 years old. Green waste from pruned and chipped ornamental trees makes an excellent mulch. Avoid using trees such as Mesquite with their large thorns and palm trees which decompose very slowly. Organic mulches such as wood mulch return nutrients to the soil, increase microbial activity, retain moisture around the plant roots, reduce weed problems and help keep the soil cool.

Fruit trees at Orchard irrigated by modified flooding:
bubbler and basin

Asparagus turning brown in the winter

Irrigate fruit trees deeply every 10 days. After leaf drop, irrigations can be applied every 10 days to two weeks if you have a surface mulch applied to the soil. Sandy soils may require irrigations weekly to every 10 days. Heavier soils may require an irrigation every two weeks.

Applying compost to the raised beds

Cut down asparagus. Asparagus growth is cut to the soil surface when it turns yellow or brown. If this does not happen by the end of the month, cut the asparagus down to the soil surface.

Compost planting beds to be rototilled. Those beds which have not been planted should be prepped for next season. Use a high grade of compost to improve the soil to a depth of 12 inches. Incorporate a high phosphorus fertilizer in the planting row or in the backfill when planting transplants.

Borer control. This time of year concentrate on removing borer damage from fruit trees. Look for borer damage on the upper surfaces of limbs, particularly of peach, nectarine and an apricot. Using a sharp, sterilized knife remove the damaged wood from these areas. Be sure to cut all the way down to fresh wood when removing damaged wood. Let the tree heal by itself. Do not apply pruning paint but you could apply whitewash.

Whitewash applied to fruit trees

Dormant oil application. Dormant oil is an insecticide made from petroleum products used in organic production. The oil itself is not toxic but spraying it on the limbs and trunk of fruit trees helps to suffocate overwintering, usually soft bodied, insects that are pests of tree fruits. Usually to applications are made during the winter months.

Weed control. Weeds that are living close to your fruit trees provide homes for overwintering insects. Once your trees begin growing in the spring, these insects move from weeds to your trees. Keep in areas near your fruit trees without weeds.

Borere control with a sharp knife

Renew whitewash on fruit trees if needed. Whitewash provides a light colored covering to the outside of the bark of the tree and its limbs. It is particularly important in reducing sun damage to fruit trees due to our high light intensities. Whitewash can be made by diluting white latex paint with an equal amount of water or more. Dilute the white latex paint so that it will color exposed areas of the tree white and reduce sunburn. Reducing the sunburn will reduce the damage from borers.


Pull wood mulch away from the trunks of young trees about a foot. Wood mulch that gathers around the trunks of small trees can damage them.

Limb spreaders on a young apple tree

Remove any stakes from trees planted early in the year. Fruit trees that are planted correctly and are not overgrown in their containers will need staking for only one season. If your trees have not become established after one season, there is a problem.


Remove limb spreaders that were used earlier in the year. Limbs spreaders are used to increase a limbs angle of attachment to the trunk of the tree. Ideally, this should be a 45° angle. Limbs spreaders can be applied to the tree now but there is less danger of breakage in larger limbs when the sap is flowing in March. Ideally they should be applied when the limbs are one to two years old.

The Problem I Warned About on Pruning Pine Trees Just Happened


I said it might happen and it did.
http://xtremehorticulture.blogspot.com/2011/09/problem-with-pruning-pine-trees-so-they.html

This pine tree has a limb that broke in a
windstorm not too long ago. It is just
at the bottom of the trunk.

Thinning pine trees by removing smaller limbs from larger limbs (thinning the canopy) is NOT a good idea. This has been a relatively recent trend in tree trimming (I do not want to call this arboriculture) is done to reduce the potential that trees will blow over in high winds. Instead, thin the canopy  by removing entire limbs from the trunk to reduce wind damage and blowover . Here is why.


Plants grow both in length (called primary growth) and width or diameter (called secondary growth). When secondary growth occurs along a limb or trunk, progressively, as it get longer, then the limb or trunk exhibits "taper" or a gradual increase in girth along its length. This is good unless you are growing trees to use as telephone poles or for lumber.


A plant develops taper along its trunk or large limbs if the trunk or limb can bend freely in the wind as it is growing. The free movement of the tree trunk or limbs increases the degree of taper. If the trunk or limb is held so that it cannot move (staking so no movement occurs), primary growth increases but its growth in girth (consequently its degree of taper) decreases.

Here is the limb that broke

Taper also inceases if smaller, lower limbs are left attached to a limb or trunk. These smaller limbs, with leaves attached,  send carbohydrates manufactured in the leaves or needles back to the limb or trunk. This helps "feed" secondary growth causing more taper at areas closest to those small limbs. A distribution of smaller limbs along a trunk or limb causes an increase in its degree of taper. On the other side, removing these smaller limbs along a trunk or limb REDUCES the degree of taper.

The limb that broke is in the center of the picture. Notice
how little taper the limbs have. Leaving all the growth
at the ends of the branches also causes the limbs to have
a "weeping" effect.

When a trunk or limb bends, and it is tapered, the stress of the bend (shear) is distributed along a great deal of its length. If there is little taper to a limb or trunk, then the stress is localized at a very small portion of its length. When a limb is not tapered, the stress of bending causes the limb or trunk to "snap" (shear)  at its weakest part or where the majority of the "load" or stress is localized.

Here are three principles to follow to increase taper in a tree:
1. When planting a tree, make sure stakes are located as low on the trunk as possible. Tree stakes should keep the rootball or rootsystem stabilized, not the entire trunk. The trunk and limbs should be free to move in the wind if possible.

2. Remove stakes as soon as possible after the root system has become established. This should normally be one season or less. If it is longer than this then you may have a problem.

3. Leave smaller limbs attached to the trunk for three to five years if they are healthy and vigorous. Try to maintain a ratio of canopy length to pruned trunk of at least 2:1.

Fertilize Lawn in the Winter?

Q. I remember you said to apply fertilizer to a lawn around Thanksgiving. But during that time it was cold and the fertilizer bag says to water frequently.

A. Fertilizing is different from seeding. I recommend fertilizing tall fescue with a high nitrogen fertilizer around Thanksgiving. This helps keep the lawn green through the winter months. Once the fertilizer is applied, it should be watered in with a single, normal irrigation. If you haven't done it yet, it may not be too late. Pick a warm, winter day and apply a high nitrogen fertilizer.

            Weekly waterings after that will be adequate to move the fertilizer into the soil and made available to plant roots. High nitrogen fertilizer applied just before cold weather helps keep lawn grasses green and better looking for a longer time into the winter.

            Watering once a week after you apply a fertilizer is adequate for fertilizer but not adequate for seed. This is not time to seed the lawn. That has to be done when temperatures are still relatively warm but not too hot; usually from September 15 through October 15 or thereabouts.

Help Me Save My Lawn!

Q. I have some problems with my lawn and I sent you some pictures. I am a recent transplant here from Chicago and I am not sure how to manage this lawn and get it flush, green and thicker. The lawn has bare spots and the tree in the center of the lawn has roots on the surface of the soil. How should I repair this lawn? How do you manage a lawn here? Is this lawn savable? Was the tree planted too shallow? What is this green net in the lawn I found? I remember you said to apply fertilizer to a lawn around Thanksgiving. But during that time it was cold and the fertilizer bag says to water frequently.        

A. Thanks for sending the pictures. That really helps a lot. Yes, your grass is savable but there are some important things that you need to check out before we can proceed. I hope you understand the importance of water and if water is not applied appropriately it doesn't matter what you are trying to grow, it will not do well. The first thing you must do is check the irrigation system. These are the things that your irrigation system should do for your lawn if it is going to be successful here.

            From the look of the lawn it appears to be tall fescue. Make sure the irrigation sprinklers, pop-ups, rise 4 inches above the lawn. Some pop-up sprinklers are 2 inch, 3 inch and 4 inch. With tall fescue it is important that these are 4 inch since the lawn will be mowed at 2 inches or higher. 2 inch pop-ups are not adequate and you must replace them with 4 inch pop-ups. The pop-ups operate on a spring. You have to pull will pop up with your hands to measure the height or turn the irrigation system on.

Head to head coverage

            Next, when the irrigation system is on the water from one sprinkler should be thrown all the way to a neighboring sprinkler to get head to head coverage. 100% coverage or head-to-head is very important for sprinkler system to operate efficiently in the desert. Thirdly, when the sprinkler system is operating you should see droplets coming from the sprinkler and it should not be fogging or misting. If you see fogging or misting the from the sprinklers this is an indication that the pressure of the system is most likely too high.

Pressure regulator

            A pressure regulator would then be installed on your irrigation system to lower the pressure within the manufacturer’s suggested operating pressure which is usually somewhere around 40 or 45 PSI. Or you can replace the nozzles of the sprinkler pop-ups with pressure regulated nozzles. This may be a less expensive option for you since the nozzles are relatively inexpensive. The nozzle unscrews from the top of the pop-up. If the pressure of your system is 60 or 70 PSI you will definitely see some fogging if these are the older type nozzles. You should make sure that the nozzles are matched. This means that they all come from the same manufacturer with the same specifications or model.

            The pop-ups should be spaced such that the water from one sprinkler should be thrown far enough so that it hits the neighboring sprinkler. This is head-to-head coverage or 100% coverage. Making sure you have 100% coverage will give you better uniformity in the application of the water to your lawn.

Small triangular piece of lawn in upper right that makes the
lawn difficult to irrigate without water running into the
street, over watering the lawn or under watering the
small triangular piece

            I noticed on one of the pictures there is a small, triangular space as a part of the lawn. This will always be a problem for you since water cannot be applied efficiently and evenly to a small, oddly shaped space. The best shapes for lawns are square or rectangular since water use thrown by sprinklers in straight lines and distances varying from 10 to 18 feet depending upon the nozzle.

            As part of your maintenance program you should be checking to make sure the nozzles are not plugged and clear the grass around the nozzle. I would strongly suggest that you not let someone convince you to cut the lawn short around the nozzles instead of replacing them. Yes, this is an easy temporary and inexpensive fix to the problem that tall fescue must not be cut shorter than 1 1/2 inches or you will see weed invasion of your lawn in these areas. The principal weed that will invade your lawn in these damaged spots will be common bermudagrass.

Depressions in lawn around sprinkler due to a line trimmer
instead of replacing the two inch popup with a four inch
popup

            Now the tree. The tree was not planted too shallow. This is an older tree. Because I could only see the trunk I could not determine what kind of tree it is but from the picture this is a tree which tends to have roots that grow toward the top of the soil. Or, the tree has never been irrigated deeply and so has grown its roots on the top of the soil where most of the water has been applied. Or, it can be a combination of the type of tree and shallow irrigations. Some trees are notorious for having shallow roots. The next question is whether the roots could be removed. This would be difficult to answer without knowing what type tree but it might be possible.

Differences in texture between a coarse textured tall fescue
like K31 and turf type tall fescue. The Kentucky 31 tall
fescue was seeded into the finer textured fescue to
save money, from an old slide of mine.

            It is also possible if the tree creates a lot of dense shade underneath it that the lawn will begin to thin due to a lack of light. In this case, the usual recommendation is to begin to remove lower limbs and thin the canopy of the tree to admit more light for the lawn. An option you might consider if you want the lawn to remain is to remove the tree. Another option if you want the tree to remain, is to remove the lawn and revert the landscape to a desert themed landscape.

            Fertilizing is different from seeding. I recommend fertilizing tall fescue with a high nitrogen fertilizer around Thanksgiving. This helps keep the lawn green through the winter months. Watering once a week after you apply a fertilizer is adequate but not adequate for seed. This is not time to seed the lawn. That has to be done when temperatures are still relatively warm but not too hot; usually from September 15 through October 15 or thereabouts.

            This time of year would be difficult to establish grass due to cold weather. You will now have to wait until around the end of February if you want to seed with tall fescue. When choosing seed to reseed the area, choose good quality tall fescue seed. It will not make much difference which seed you use but do not use inexpensive seed. Avoid K31 or Kentucky 31 tall fescue seed in this particular case. This is a pasture grass and not suitable for residential landscapes.

Plastic netting on a roll of tall fescue sod.

            General maintenance of a tall fescue lawn would be fertilizing on Labor Day, Memorial Day, Fourth of July and Thanksgiving. If you are mowing with a mulching mower and returning the clippings back to the lawn and then you can skip your Fourth of July application. The fertilizer that you use should be high in nitrogen, low in phosphorus and moderate in potassium. These represent the three numbers on the fertilizer bag. If you were to make a ratio of these numbers by taking the lowest number and dividing it into the other two the ratio should be 3:1:2 or 4:1:2. Examples might be 21-7-14; 15-5-10; 20-5-10, etc. These numbers do not have to be precise but they should generally be in those ratios.

            The green netting came with the sod when it was planted. The netting held the sod together. Do not pull on the netting. If you pull on the netting you may very well pull up the grass. Instead, cut the plastic netting and remove it. If someone pulled on the netting previously this may be a reason for the bare spots. I hope this helps answer some questions.