Xtremehorticulture

Xtremehorticulture of the Desert

What Todo To Vegetables March and April

Leave a Comment / what chemicals do I use, what do I do to a vegetable garden now, what insects are garden pests /

This is what we will do with vegetables during these months. Look for tomato hornworms to be active in April. They attack grapes as well as tomatoes. The adults, the sphinx moth, has been flying now for two weeks and laying her eggs which turn into the hornworm. Found this sphinx moth lying on the sidewalk during a walk. This was two weeks ago. They are flying so horn worms will be a problem soon. Below is a hornworm, the larva of the above moth. I got this picture from the internet since I dont have a good pic. Sorry to whoever’s this was. I don’t have the reference anymore. New transplants, protect from cutworms with Bt or spinosad. Spinosad is harder on bees but gets more different types of insects. More information on spinosad. Bt comes as Dipel or Thuricide. Spray on leaves and will leave a residual for a few days after you spray and then it is gone. Respray weekly for the next four weeks. The insect has to “eat” leaves that have the Bt on it. More information on Bt. They are both “organic”.  Fertilize with a high nitrogen fertilizer once a month. This can be blood meal or a conventional nitrogen fertilizer such as ammonium sulfate (21-0-0). Aphids are out. They overwintered on your other plants and weeds in the yard. They are easy to control with insectidal soap, Neem or other products. But they will be on the UNDERSIDES of the leaves so make sure you spray on the undersides of leaves, not just the tops. Direct the spray up under the foliage when you spray.

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Using Limb Spreaders in Fruit Trees

Leave a Comment / how to spread limbs apart, why is my fruit tree growing up /

Plums, European pears and Asian pears have a tendency to grow vertically upright and narrow. If caught early enough, young limbs can be trained to grow less vertically and into the more desirable 45 degree angle… Plums, European pears and Asian pears have a tendency to grow vertically upright and narrow. Upright or vertical growth tends to be faster growing and produce less fruit. If caught early enough, young limbs can be trained to grow less vertically and into the more desirable 45 degree angle which provides a better balance between leaf and shoot growth and fruit production. One way to do this is the use of limb spreaders. Wooden limb spreaders for spreading fruit tree limbs into a more desirable 45 degree angle. Limb spreaders can be placed between a narrow limb and the trunk so that the limb is “pushed” and trained to grow in a less vertical position. The angle we would like to achieve is about a 45 degree angle from horizontal but should be done to smaller diameter stems when the sap is “flowing”. The so-called flowing of sap is when the trees exhibit growth. At this time the branches are more supple and can be bent more easily without breakage. Pounding a nail into the V of the limb spreader and then cutting off its head is a way to give your limb spreaders more “bite” when holding the limbs apart. I don’t like to do this unless I really have to. It can damage the limb.  Limbs that are three years old and less can be bent into more horizontal growth through the use of limb spreaders. Occasionally older branches can also be forced.  Use limb spreaders to push branches that are too vertical into a more horizontal habit. Limb spreaders are usually made from 1 x 2 inch wood stock or wood lathe.  This stock is cut into the lengths that are needed, notched on both ends, with finishing nails driven in to the center of the notch.  The heads of the finishing nails are then cut off.  The finishing nails help prevent the spreader from slipping on the branch.   Limb spreaders can be made in different lengths to handle different spacings when needed. If you can’t find or don’t know how to make limb spreaders, we have them available in different sizes at the Orchard if you can’t find them or don’t wish to make them yourself.  All we are asking is a small donation toward the Orchard maintenance fund.

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Texas Ranger (Sage) Getting Woody

Leave a Comment / hedge shears, pruning correctly, rejuvenation pruning, renewal pruning, shearing /

What should I do and when should I do it? Q. My Texas rangers have become very woody. Each have 2-2gph emitters and are watered for 40 min. 3 times each week. One is close to other plants and is probably stealing water from them. So, what should I do and when should I do it? A. Basically they have been pruned with a hedge shears or pruned like they were hedged. This has caused the outside of the canopy to become thin with lots of interior older wood. It will get progressively more like this with time and become more and more sparse unless the plants are allowed to get much larger. You have three options.             Let them get larger. This will allow them to put on sufficient new growth on the outside to cover up the sparseness of the foliage and the very old interior wood.             Second, you can do some corrective pruning. This may make them ugly for a couple of seasons but you will be on your way to re-establishing the plants with a better appearance and longer life. This would require two to three cuts deep inside the canopy, opening the canopy for new growth and re-establishing a new canopy. A caveat. I did not do this pruning but I saw it and it demonstrates an idea. The idea is the concept of renewal pruning. Renewal pruning is cutting back about 1/4 to 1/3 of the shrub every couple of years so that you have a “new” shrub every 6 to 10 years. This helps keep the shrub green from top to bottom and avoids it from getting woody at the base.             This will leave them looking like a gap-toothed 7 seven year old for a few months until they fill in. Next year remove two more and let it recover. By the third year you should have removed most of the older wood and the shrub should be well on its way to looking and performing better.             From that point forward you would renew prune the shrub every two or three years. This means that every two or three years you could take out maybe two of the oldest stems from the base and let it regrow out. That is all the pruning required on this plant. Another option is called rejuvenation pruning.This is basically cutting the shrub to within a couple of inches of the top of the soil or mulch and letting it regrow from these “stubs”. This does not work with all shrubs so make sure it works on the shrub you are thinking of doing it to before you do it. If you are not sure it will work on a specific shrub, cut one of the stems back to a couple of inches and watch what happens during the next growing season. Cutting shrubs down within a few inches of the soil or mulch surface is called rejuvenation pruning. Oleanders respond well to this type of pruning. Be careful though because not all shrubs will respond favorably to this drastic form of pruning.              Here is a shrub that was attacked by a hedge shears. Notice that there is sucker growth coming from the base. This is an excellent sign that this shrub is a candidate for either renewal or rejuvenation pruning.  Third is to pull them out and replace them and start pruning them the correct way which is without a hedge shears but two or three deep cuts every two to three years.

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Iris Not Blooming Any More

1 Comment / dividing iris, no flowers, overcrowding, when to divide /

They bloomed for many years but the last two years they had no blooms. Is there anything I should be doing? Q. I planted several bulbs of iris in my yard about 7 years ago. They bloomed for many years but the last two years they had no blooms. Is there anything I should be doing?  I clean out all the dead leaves between bulbs and have removed a couple of bulbs. They are watered same as other plants according to the time of year for 25 minutes. A. The usual problem when iris is not blooming when they were when they were younger is not dividing them.             They must be dug up, the rhizomes severed, dusted with a fungicide and left to heal for a day or two in the shade, spaced appropriately and replanted. Throw out damaged or rhizomes that are too small unless you want to baby the small ones until they get enough size to bloom.             Distances apart depend on the size of the iris; smaller ones closer together and larger ones further apart. Taller ones toward the back and shorter ones near the front.             Replant them with compost and a starter fertilizer mixed in such as bone meal. Fertilize once a month lightly with a good quality flower fertilizer.             But overcrowding will cause them to stop blooming. They are in the same spot so I am figuring the light is the same unless some trees got bigger and limited sunlight to them.             For watering a large iris bed I would use low pressure, in-line drip emitters in half inch poly pipe such as Jain or Netafim brands preferably. Space the pipe about 12 inches apart parallel to each other throughout the bed. They can be laid on top of the soil, just under mulch.

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Is This Verticillium Wilt in My Olive Tree?

Leave a Comment / disease, limb dieback on olive, olive diseases, olive dying /

Do you think the sparse looking tree could have verticillium that you mentioned in your newsletter? Q. I need your help again. I have two Swan Hill olives trees in the back yard. One has lost a lot of leaves and looks sparse and the other looks good. I have also taken a couple pictures of of the problem tree. Do you think the sparse looking tree could have verticillium that you mentioned in your newsletter? A. The tree looks pretty young and I would not expect it this soon in its life if it appeared at all. This disease is not common here.             It is hard to really know if the disease is present or not just by looking at a tree. Olive has few problems.             It is by deduction. Verticillium wilt causes limb dieback in trees. My olive tree has limb dieback. Therefore my olive tree has Verticillium wilt. That’s how it is diagnosed now without sending a sample to a pathologist.             Typical Verticillium wilt symptoms do not occur in olive like they do in other trees. Upon close inspection of an infected limb, olive looks normal instead of having the vascular streaking common to that disease.             Two things you can do; watch it and see if it gets worse or send a sample to the state pathologist with the Nevada Department of Agriculture. This would be in Carson City. His contact information is on their website or call their local office at 702-486-4690.             I would not cut any limbs or remove them until you have some better idea of what is going on from a source that does not profit from tree removal. In the meantime, water it frequently and deeply. Fertilize it now for good growth.

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What is a Good Patio Container Fruit Tree?

3 Comments / citrus for containers, patio fruit trees, patio garden /

Q. I live in a 3rd floor condo that faces south. I get about 7 hours of direct sun and have containers on my patio with spinach, tomatoes and peppers that are doing well so far. I was wondering if there are any types of fruit trees that produce and thrive in a patio container? A. Yes, there are. I worry a bit about the weight that this will place on your patio. Make sure it can handle this type of load before you attempt containers there.             There are light weight soil mixes that can be used to lessen the weight load on the patio. These mixes frequently use amendments like perlite that replace heavier components of the mix.             A good citrus to grow in containers in our climate is cumquat. It is tolerant of very low Cumquat fruit about 1 1/2 inch long temperatures, as far as citrus goes, and stays very small. Tender citrus to use would be limes and calamondin, sometimes called calamansi, but they will need protection from winter cold temperatures. Citrus espalier or some might call “trellis”             You can use any of the genetic dwarf fruit trees in containers. I would trellis the tree near an available wall. If you select a genetic dwarf fruit tree the container needs to be large. Citrus in an espalier             If your patio is protected from wind and cold you might consider kiwi, passionfruit, giant passionfruit or dragonfruit.

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How To Correct Winter Damage to Star Jasmine

Leave a Comment / dying, how to fix, leaf bronzing, star jasmine leaves yellow /

Q. What is the best way to fix frost damage to star jasmine? Give them nitrogen and iron? Wait for warmer temps? Or replace the plant? A. Mild freezing damage to many plants, including star jasmine, discolors the leaf causing it to yellow or bronze but not die. At lower temperatures the leaf may scorch, drop from the plant or dieback and still remain on the plant.             If winds are light, cold damage during mild freezes is more severe at distances further from the ground. The ground can radiate heat up to the plant, keeping the lower portions from freezing, if winds don’t continually blow it away.             If tender plants grow both above and below a wall, it is not uncommon to see the top portion damaged while the parts below the wall remain in good condition.             You sent me a picture of a star jasmine used as a ground cover. In the picture, most of the discoloration from cold is in the upper part of the plant. That discoloration is permanent to those leaves.             You have two options; let it grow out of it in the next couple of months and prune out some unsightly parts that still remain or make some deep pruning cuts inside the canopy. These deep cuts will be focused on stems with loss of leaves or discolored foliage.             Follow up with and all-purpose flowering tree and shrub fertilizer and some irrigations to wash it into the root zone. I would not replace the plants.

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Weather Report for UNCE Orchard for February 2014

Leave a Comment / did it freeze, Las Vegas, north las vegas, what were the tempertures /

We had freezing temperatures during the first three days of February in the middle of the night in two instances. There were some peaches and apricots in bloom at the time whose fruit crop might have been affected. Wind gusts during this time did occur on February 1. We did have wind gusts a few days during the month. Certainly on February 2 they were. at night on January 6 and 8th. Winds did not compound the problem. Humidity dropped to single digits twice during the month. No major rainfall events. ET was about 2. 4 inches during the month of January. Generally speaking, irrigation should have added about 2 inches of water in January, 2014. The UNCE Orchard is located at 36 degrees North Latitude and 2000 ft (666 meters) elevation in the Mojave Desert north of Las Vegas, Nevada, USA. The weather station sensors are located at about 7 feet above ground level in an deciduous orchard setting just above tree canopy. The soil temperature probe was accidentally above the soil surface for a few days but was reset to about 1 1/2 inches (4 cm) below the soil surface covered in wood mulch. Reported by Mike Barrett.

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Garden Problems Answered Mondays and Fridays

Leave a Comment / garden problem, help with garden, where can i get my gardening questions answered /

I will be at the Viragrow every Monday and Friday to answer questions through March, 7 am to noon. Bring samples, pictures or descriptions. Or just come and chat about gardening. I will be glad to listen, we can talk and have a cup of coffee. I will be not be at the Viragrow location on Mondays and Fridays from April 7 to April 25 but I can be reached by email at [email protected]. It is always good to make an appointment if you are coming and make sure I can meet you. Bob Morris aka Extremehort  

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Preventing Thrips Scarring to Nectarine Fruit

Leave a Comment / deformed, nectaine fruit damage /

Western flower thrips are the major problem with growing nectarines in the Las Vegas valley.If not sprayed, fruit can get terribly scarred. The fruit is safe to eat, but who would want to? Nectarine fruit scarred from Western flower thrips These tiny insects appear at the time of bloom and begin ripping and tearing into the surface of the immature fruits as soon as the blossoms drop from the tree. If left unchecked they continue to rip and shred the fruit surface with their rasping mouthparts causing the fruit to scar and leak sap. The leaking sap crystallizes and remains attached to the fruit where it is scarred. The resulting fruit is deformed, ugly and looks inedible. But it is not. The fruit is still good and tasty.             Western flower thrips. Picture from University of California IPM Project. To keep the fruit from becoming scarred and deformed, pesticide applications must be used. One of the best organic approaches is to use the insecticide called spinosad. Spinosad is applied to the fruit with spray applications until harvest. It should be combined with a spreader/sticker additive to the spray mix. Follow label directions.   It doesn’t say it but this product from ferti-loam has spinosad in it and is labeled for fruit. Otherwise look for the name Spinosad in the ingredients. It is a must to change off your pesticide applications with others to prevent the possibility of developing chemical resistance to this product. This is called rotating your chemical applications. Other organic sprays you can alternate with include insecticidal soap, and neem oil.

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