Xtremehorticulture

Xtremehorticulture of the Desert

Mechanical Control of Borers in Fruit Trees

Leave a Comment / borer damage, borer repair, knife, organic, without pesticides /

I will usually take a very sharp, large knife and remove this loose bark and find out how much damage has been done by the borer. No one talks about this subject probably because no one has really tried it much in the past. Borer problems in fruit trees in Las Vegas are usually from two different possible insects; flat-headed apple tree borer or the Pacific flatheaded borer. The damage from both of these insects are very similar. They usually damage areas of the tree damaged by intense sunlight. This means the upper surfaces of limbs and the sides of limbs facing south or west. Early damage from borers starts with this brown crystalline sap coming from damaged branches. When it rains this sap gets very gooey like petroleum jelly. This is peach but the limbs have been whitewashed. More borer damage on the same tree. Damage does not usually cause limb dieback unless the limb is small or the problem has been developing in the tree for a couple of years. With repeat attacks the limb becomes weaker, the vascular system that carries water and nutrients is severely impeded and then we see branch dieback and flagging (leaves dead on the tree without falling off). When damage from borers has been going on for quite some time the lifting of the bark can be extensive and damage can extend nearly all the way around the limb. I will usually take a very sharp, large knife (not a pen knife, this would be dangerous) remove this loose bark and find out how much damage has been done by the borer. If the damage has not extended over half way around the limb I will remove the bark all the way down to fresh wood. The dead wood and bark is completely removed from the limb and the limb is allowed to heal. Nothing is applied to the limb but time. In our many years of doing this in the orchard I would estimate that over 50% (very conservative estimate and it is probably closer to 80%) recover with this method. I can only guess but removing the loose bark takes away any hiding places the adult will have when it exits the tree, if it does.  If successful, the tree heals over the wound in two to three years. Peach tree borer repair with a knife and healing of the upper surface of the limbs.

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Sneezing Might Be Due to African Sumac

Leave a Comment / African sumac, allergies, ash, Las Vegas, mulberry, pine /

Ash trees are starting to bloom now as well. I have noticed that African Sumac has been flowering and is still flowering now. If you have been sneezing over the past couple of weeks, this could be the problem. Ash trees are starting to bloom now as well. Flowers of African Sumac I know you could say fruit trees, flowering plum, ornamental pear are flowering too but usually plants with brightly colored flowers do not contribute much to allergy problems. Flowers of ash. Coming up very soon are mulberries, pine and canary island date palms for allergy sufferers.

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Brown Spots Probably Disease Problem on Tree Photinia

Leave a Comment / anthracnose, brown spots, photinia leaf spot disease /

Q. Can you tell what the problem is with my patio tree and what I can do about it? The leaves are all covered in brown spots. I am not sure which plant it is. A. From the looks of the plant it seems to me to be a photinia pruned as a patio tree. From the pictures you sent with the black spots on the leaves I think it is either photinia leaf spot disease or more likely, anthracnose. Neither one do we see much here.             Both diseases can attack photinia and Majestic Beauty hawthorne so if your tree is either one of these, this might be the problem. Majestic Beauty is particularly prone to anthracnose while the smaller shrub-type hawthornes usually are not.             Unhealthy plants are MORE likely to get a disease than healthy ones.  Anthracnose usually makes dark brown or tan spots that look like irregular targets with concentric irregular rings in them.             Poor air circulation and wet leaves will make this disease worse. These diseases are thought to spread when leaves are wet or if you spray them with a hose to keep them moist. So irrigate only at the base of the tree and do not spray the leaves.             The tree and the interior of its canopy need air circulation to stay dry. Prune out entire limbs from the trunk or branches so that air can move through the canopy and not stagnate.             Leaf spot disease is caused by a different fungus and can re-attack the tree year after year if you don’t pick up diseased leaves that have dropped and dispose of them.             The disease is less likely to be active when it is hot out. So if you have to spray the foliage then avoid doing it during the cooler months. Do it during the summer in the morning hours.             I noticed something on the bottom of your leaves when I magnified the picture you sent. Aphids? Soap and water sprays on the undersides of the leaves will control them. Do it every three days for about four applications.             Your tree is not in the best of health. Apply iron chelate in the form of EDDHA and a good flowering tree fertilizer now, in very early spring, and once again later in the season.

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Majestic Beauty Hawthorne a Good Choice But Use Wood Mulch

Leave a Comment / Bay laurel, indian hawthorne /

Q. On the north side of our house we have a 10-foot wide space we are trying to landscape. Several have suggested planting bay laurel trees but we are concerned about the tree’s size for the space. When we went to the nursery their suggestion was the Majestic Beauty hawthorn tree. Will the Hawthorn tree do well in our climate and soils? A. Yes, the Majestic Beauty Indian hawthorne is fine and could work for you. Probably a better choice than the California bay laurel. Bay laurel struggles in our climate unless they are protected from late afternoon sun. Northern exposures can sometimes get hammered by the late afternoon sun.             Both plants do better with wood mulch rather than rock mulch. Use lots of compost mixed into the planting soil at planting time.             Keep wood mulch a foot from the trunk the first three or four years after planting. Use at least four inches of mulch and it should cover a distance of at least 6 feet in diameter under the tree. More information on Majestic Beauty 

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Wild Mustard is Free and Available For Your Salads All Over Town

Leave a Comment / is it safe to eat, what does it look like, when to pick, wild mustard /

Mustards are all over town right now and they appear like weeds. But what you may not know is that they are at their peak of flavor right now, particularly the younger, smaller leaves toward the center. This is the “wild” version of collard greens. They They can be harvested along walls, in empty lots, your own yard just about everywhere. They are what we call “winter annuals”. They seed of winter annuals like wild mustard germinates in the fall and puts down a “rosette” of leaves before winter cold sets in. That is the rosette you see below. As soon as we see some warm spring weather they shoot up a central spike with their small, yellow flowers. The flowers form a seed capsule which drops the seed on to the soil and which will germinate during the early fall months into the rosette and the cycle starts all over again. These “weeds” can be used to spice up your salad mix just like other greens you might use. Start harvesting in late December but get the leaves picked before it gets hot. Smaller leaves are more tender. Make sure you wash them. They will keep in the refrigerator for several days, just like lettuce and spinach would. As the air temperatures get hotter the leaves will become thicker and more leathery and the “spiciness” will increase. They will die out as the summer heat approaches and after they send out their seed stalk with small yellow flowers.

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Can I Use Compost With Worms in It?

5 Comments / armyworm, compost, cutworm, damage, decomposers, Miller moth, pupae /

Q. I have been collecting vegetables scraps for the last 6 months for composting but did not have a cover on my bin.  I have found the compost loaded with this bug or worm.  Can I use this compost? There are too many to pick out.  I’m afraid if put in soil they will kill plants but my compost is really good!! A. This is pretty common in compost. This question is one of the most common questions asked about composting on my blog.             Many of these types of insects feed on decaying foods and composts that are not quite finished composting. Once the compost is finished they are seldom a problem.             I don’t know how much compost you are talking about but if it is possible to layer out the compost the birds will come in and gobble them up.             You can cook them in the sun and they will decompose in your compost. To do it correctly the compost must be “fluffy” or loose enough to allow the heat to spread through it evenly.             Spread the compost in a layer several inches thick. It should be slightly moist but not wet. Cover it with a clear plastic drop cloth and hold it in place with some nails or staples. The edges of the plastic must be sealed so no heat escapes.             Hold it in place with some rocks, blocks or bricks so it does not blow away. Leave it in direct sunlight for about two weeks. The temperature will get hot enough to kill most of the insects. Maybe pupa of cutworm or armyworm? Pupa is the transitional stage between larva or worm and the adult. In these cases moths. The adults are moths that you will see flying around your porch light at night. As a kid we used to call them “Miller moths”. Kind of dusty, maybe an inch across. They used to fly right into the light and sometimes get “fried”. When you see these moths, the eggs they laid will hatch in a few days and it is time to put down some Bt sprays or dusts on your vegetable garden.

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Dark Brown or Black Shells on Oleander May Be Scale Insects

2 Comments / ants, brown apricot scale, control, insecticide, lecanium scale, oleander sticky, scale, sugar /

Q. I have a serious infestation of hard shelled black insects on my oleanders. I have a tree-like hedge of oleanders on both sides of my home. One of the oleanders is heavily infested but the problem is spreading rapidly to all the others. When I discovered the problem this weekend the oleander was black with thick black shelled insects about the size of an apple seed with sticky honeydew dripping down the trunk and stems. My neighbor thought they were black aphids so I power sprayed the oleanders with water and used a soapy water rinse. Unfortunately, the bugs seem to be adhered and need to be picked off. They are not on the leaves but are on the stems and trunks and climb higher than I can reach. I am attaching photos and would appreciate any advice you can give me. Will the 100o+ weather kill them? I removed the most heavily infested branches but that barely made a dent in the insect population so I wonder if I have to remove the whole oleander tree. A. This is one of the many scale insects. Scale insects are not terribly common in southern Nevada. They are difficult to control because the insect is living under a protective “shell” it created.             Because the insect does not move around once it creates its “shell” they don’t attract attention. Frequently they come to our attention because of the sticky sap they excrete is shiny and attracts ants.             Oftentimes the question becomes how can I control ants, not realizing the ants are there because of other insects like scale and aphids. The ants can move the scale insects around so it is best to control them as well.             If you don’t have very many of them you can treat each scale with alcohol and a cotton swab. But usually there are too many.             The usual recommendations for controlling scale insects is to either spray a horticultural oil on top of them in early spring to suffocate them or use a conventional insecticidal spray. a conventional insecticide when the insect is no longer protected by its hard outer covering, the scale itself. Never spray an oil when a plant is in bloom. Usually two winter or early spring applications are called for. One of the many horticultural oils for suffocating insects. Particularly good on soft-bodied insects like aphids, mites and the like but they will also kill beneficial insects so use it where and when it is needed and not indiscriminately. These insects are not hard to kill when they are not under those shells. The females release young scale insects without the scale (called crawlers) around May. It is at this time the insects are most vulnerable. It is also the time when it starts getting hot and the spraying oils in the heat is not recommended. I have done it very early in the morning with no problems to the trees but you must do it early in the morning. When in doubt, spray a small area of the plant first and wait 48 hours to see if the plant reacts negatively to it. If it doesn’t, go ahead and spray in the summer as well but do it in the cool morning hours right after sunrise.

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Clover-Looking Weed with Yellow Flowers is Very Difficult to Control

Leave a Comment / herbicides, iris, Las Vegas, lawn, Mohave Desert, Mojave Desert, nevada, oxalis, shrubs, weed control /

Q. I have oxalis clover look-alike as a weed. How can I control it? I am ready to use chemicals at this point having tried to rid it by digging and pulling with no success. Having it in my grass is bad enough but now that it is in my iris beds I want to kill the dang stuff! Oxalis looks like clover but has yellow flowers that resemble a daisy with only five petals. A. Oxalis is very difficult to kill. It may require repeat applications but one of the keys is to try to kill it when it is “happy” and is ready to grow and multiply. This is usually spring and fall. Go to your favorite nursery or garden center (you may have to look at several such as Lowes, Home Depot, Star and Plant World). Go to their weed killer section. Look at the active ingredients. Look for the following in the active ingredients list. The important chemicals to find on the label are either Dimethylamine salt of dicamba: 3,6-dichloro-o-anisic acid (it may be just called dicamba or Banvel) somewhere on the label. The alternative would be an ingredient called triclopyr, (chemically called 3,5,6-Trichloro-2-pyridinyloxyacetic acid) These chemicals are usually combined with other weed killers for better synergism (efficacy or improved performance). In cases of herbicide synergism 1+1 = 3 times more effective. So you may see 2.4-D listed as the first chemical (Dimethylamine salt of 2,4-dichlorophenoxyacetic acid) or you may see 2,4-DP (mecoprop or Dimethylamine salt of (+)-(R)-2-(2 methyl-4-chlorophenoxy) propionic acid) listed as well on the label but the names in RED are the most important for oxalis control. I am sorry for the detailed technical response but this is really technical stuff to get you the right chemical. There are so many different manufacturers and labels with the same stuff in it, it is impossible to list them all so giving you the ingredients to look for is much easier. Next is the method of application. These chemicals will not damage a lawn if you apply at the right concentration but they WILL damage other plants. So you must spray them directly to the weeds and not overspray onto other plants!  Make sure you wear waterproof gloves when mixing and applying and wash thoroughly after an application. They are not THAT toxic but it is always a good precaution. Never spray on a windy day. Spray when weather is warm but not hot because the plants are better able to “absorb” the spray.  Mix about 1 tsp of ivory liquid detergent per gallon of spray to the finished mix and thoroughly stir it. Do not add it before you add water or it will just give you a lot of weed killer bubbles. This detergent helps the week killer enter the leaves.

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Thanks to Hunter for Advanced Irrigation Control at the Orchard

Leave a Comment / hunter irrigation clock, irrigation, Las Vegas, Mojave Desert, nevada, north las vegas, watering at the orchard /

A really big thanks goes out to Hunter Industry and in particular Nate Gould out of Phoenix, Arizona. Nate offered to provide the UNCE orchard in North Las Vegas with a state-of-the-art Hunter ACC Irrigation Clock. This definitely brings the UNCE Orchard into the 21st Century! Hunter Irrigation’s ACC Irrigation clock. Top of the line for all of the UNCE Orchard’s irrigation needs. Nate helped us install it so we that really cut our installation time down. (Advanced Commercial Controller) to help us better manage our irrigations for the fruit trees and vegetable plots. Our volunteers can communicate with the clock remotely so if we have an irrigation problem we don’t have to keep running back to the clock.

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Italian Cypress Will Work as a Windbreak on 1 Acre But….

Leave a Comment / designing a windbreak, establishing a windbreak in the desert, Las Vegas, Mohave Desert, Mojave Desert, nevada, planting a windbreak /

Q. I have used Italian cypress in moderate climates with very good success but now I will be moving to the desert in Pahrump on one acre and want to put in about 30-50 of these for windbreak. Is there anything special I need to consider planting these in a desert climate? Italian cypress if planted close enough can provide good wind protection…but at a cost. Living wind barriers use water. Balance the benefit you get from a living windbreak vs. its cost. Windbreaks are effective up to about five times their height. Place windbreaks close to where you need them. Too far away is a waste of time, water and money. A. Pahrump gets colder than Las Vegas and will dip down to 10°F. They have trouble growing plants which have less cold tolerance than Las Vegas. The relative humidity can drop to as low as about 10% at times but regularly is between 20 to 30%. Much like the rest of lower elevations southern Nevada, some light intensities can be about 20% higher than in other parts of the United States. Italian Cypress will work but I also am going to attach a document I wrote on windbreaks for southern Nevada. People in Pahrump love to plant these windbreaks along the edge of their properties but, in my opinion, if windbreaks are not planted in the right locations and the correct distances from the areas to be protected, you are just wasting your money and water. They make a nice wall and perhaps a visual barrier and that’s it. I hope you are young man because by the time they get large enough to be of any value as a windbreak at those distances it will be many years. Watering them on drip irrigation will work. Be sure your size your drip irrigation mainline, sub lines and laterals large enough to handle the irrigation you will expect in the next 20 years. Adding emitters to existing lines to deliver more water as plants get larger will not be a problem. But if you under size your irrigation water delivery lines by not planning for the future now and they are too small to accommodate the increased water use as these plants get larger, then you will be redoing it in a few years. Drip irrigation requires maintenance. This includes flushing lines on a regular basis and using appropriate filtration or you will have nothing but problems. You can inject fertilizer into drip lines. Expect about 12 inches of growth each year. Windbreaks modify the wind to a distance equal to about five times their height. Pahrump was a major southern Nevada farming community in the past and has good soils in many locations. Be sure to amend your soil surrounding these plants at the time of planting. I usually recommend about a 50-50 addition of soil amendment to raw desert soil at the time of planting. Our desert soils are extremely low in organic material. They will also perform better and have fewer problems if you can surround them with several inches of wood mulch. Keep the mulch away from the trunks about 12 inches for the first five years. Rabbits do not like Italian Cypress but if they are hungry enough and the population explodes due to recent fires, they will be damaged or destroyed by rabbits. I want to gently remind you that we do live in the desert. And even though there may be only the cost of pumping the water in your mind there are other “costs” as well. I like to call these social and environmental costs. Pahrump’s water basin is already overdrawn (more water is used than is replenished to the aquifer) and we need to consider this when we are designing our landscapes and gardens. We need to find a fine balance between our quality of life and respect for where we live. Living Windbreaks for Desert Dwellers

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