Xtremehorticulture

Xtremehorticulture of the Desert

How Often to Water Fruit Trees in the Winter?

Leave a Comment / irrigation schedule winter, Watering fruit trees in the winter /

Q. Do you have any guidelines for watering fruit trees in the winter?  I cant find anything specific to winter watering on your web page. I have apricot, nectarine, apple, fig, pear, plum, cherry, peach, orange – planted spring 2015.  I am not expecting the apple or cherry to make any fruit yet, They are just ornamental. Pomegranite, jujube, lime, grapefruit I planted 3 years ago. Will deep watering once a month suffice for December – February? Fruit tree with irrigation basin surrounding the trunk. Irrigation bubbler at the top right of the basin that allows 2 gallons of water to flow from it every minute. The basin must be level so that water flows evenly across its surface.Surrounding the trunk is rabbit protection. A. Once a month is not even often enough for trees established for years in our warm winter desert climate. Once they have been established, trees established for one season might be closer to every two weeks during the winter. If the soil is very sandy, then once a week. Fruit trees surrounded by dry soils should be watered more often than trees in wet soils. Wet soils in the desert might happen if fruit trees are grown close to a lawn area, a wall that has irrigation applied on the other side of it, intercropped between the trees with other plants like vegetables or herbs. Irrigation basins surrounding newly planted fruit trees that have been staked and mulched with wood chips. The screening around the trees is for rabbit protection which also keeps the wood mulch away from the trunk. If drip emitters were used, two emitters might be enough for the first 2 to 3 years. When they have reached 2 to 3 years old than increase the number of emitters to at least four. Generally speaking, if there is a surface mulch of at least three inches, add one to two days in the summer and up to one week in the winter. Sandy soils require more frequent watering with smaller amounts applied. Desert soils should contain 50% compost at the time of planting. Fruit trees perform much better with wood mulches applied to the surface and require less frequent watering. General Watering Schedule for Fruit Trees Let me run down a general schedule of watering fruit trees that is ignoring rainfall since we only receive an average of 4 inches (10cm) or rain each year. Newly planted in spring or fall during cool weather….2-3 days; winter 1 to 2 weeks depending on soil and mulch covering. After growing for one season then assume the trees are established. Fruit trees established at least one season with fruit or nuts on the tree… Summer every three to four days depending on soil and mulch. Spring and fall, weekly. Winter every two weeks. Fruit trees that have been harvested can be watered less often.

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How Should I Care for My Fairy Duster Plant?

Leave a Comment / How to care for fairy duster /

Q. I’d appreciate some pointers on how to arce for fairy duster plant So it becomes healthier and a better looking shrub. Very little has been done because the bees are usually on it. Fairy duster and honeybees A. This plant is native to North and Central America growing in warm desert climates and soils. This tells you a little bit about how to manage it. This should tell you to not water every day. Plants like this are usually very susceptible to root rot so make sure the soil has been amended with compost before planting so that it improves drainage. Fairy duster in the backyard of reader It will tolerate desert soils as well as infrequent watering. At planting time I would amend the soil with about 25 to 50% compost and make the whole about three times wider than its container. I realize yours is already in the ground so watering and fertilizer applications are important to mention. Do not water this plant too often. That will be the biggest mistake people make. Fertilize it lightly once in the very early spring around late January or February with a rose type fertilizer. The plant can get 3 feet wide and 3 feet tall in soils that have been amended with compost. As long as it’s in a sunny location you should see a profusion of blooms in the spring and summer months that attract bees, hummingbirds and night flying moths. Quail like to feed on seed from the seed pods. Rabbits like to browse on new growth. You can clean up the plant in the early spring by removing dead leaves and stems. You will encourage more blooms if the plant is in a sunny location and flowers are removed before they begin to form seedpods.

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Every Potting Soil Contains Fungus Gnats

4 Comments / How to control fungus gnats /

Q. It seems no matter what brand, no matter where I buy my potting soil I have to bake it before I can use it.  If I don’t, I get hundreds of tiny fly that hatch and swarm.  I put out water to catch and drown them. I spray insect oil on top of the soil several times a day. I’m so afraid I’ll kill the plants. A. Yes, fungus gnats are a big problem in potting soils and they can create damage to plant roots. They feed off of both decaying plant parts and soft, succulent living roots as well. Potting soil does not smell very good if you have to put it in your oven at 150° for 15 minutes to kill these nuisance critters. The larvae can cause damage to new, tender roots of plants. If they are extremely happy in their environment they can multiply very rapidly and cause some severe damage. Besides that, they are pesky and a nuisance inside the house. This is Garden Gourmet potting soil and I have never seen fungus gnats in this product. However, bagged potting soil that is not been heat treated will carry fungus gnats. This product sells for $5 for one cubic foot. If potting soil is sterilized with a heat treatment by the manufacturer it should kill all of the fungus gnats. If the soil is introduced into an environment where there are fungus gnats present then it will get reinfested again. Here is what the University of California says about them They can be controlled with some organic pest control products; nematodes that go after these larvae and a bacterium which does the same thing. You should be able to find some of these products in your local nursery or garden center. I have never used them so I am reporting only what has been reported on the internet using these methods for fungus gnat control. However, cooking them does work. Where to get beneficial nematodes Where to get beneficial bacteria  It says for mosquito control but it is the same product used for fungus gnats and will be included on the label. Another method is to sterilize this potting soil yourself by placing it moistened into a clear plastic bag in full sunlight and let it bake. Temperatures need to get up to about 160 F for at least 30 minutes for good control. Keep in mind that if you introduce this back in the environment where a fungus gnats are present and they will reinfest this sterilized potting soil. Another option is to apply pyrethrin to the soil and water it in.

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When and How to Prune Lantana and Oleander?

4 Comments / how to prune, Pruning lantana, pruning oleander, when to prune /

Q. How and when should we prune our lantana and oleanders? This is a Lantana I saw pruned by a local company. Leaving this much wood remaining will make it very “twiggy” at the base. You can actually prune it much closer to the ground in this. You can see from this close-up that I took last February that suckering can occur much lower on the stems of Lantana. Don’t be afraid to cut it close to the ground. Leave about 1 inch for suckering. A. Both of these plants are pruned during the winter months since they both produce flowers on new growth during the summer months. After pruning, apply a high nitrogen and high phosphorus fertilizer to push new leaf and stem growth and dark green color. The phosphorus will help to promote flowering. Flowering will not occur until the top growth is large enough and comes into balance with the existing root size. This is sometimes referred to as the root to shoot ratio.  I would delay pruning them until late winter (late January) unless you don’t mind looking at “dead” space (the space is not occupied by anything). For lantana it normally freezes during winter months and you have a choice whether to leave the dead top of the plant in place or cut it down to the ground, leaving one inch of stems remaining to support the new growth beginning in February. You can prune oleander close to the ground, just like Lantana. Cut it back to within 2 to 3 inches of the soil surface. This is the time of year to do it up until about the end of January when it begins to push new growth all by itself.             Because the roots are fully grown, alive and healthy you will see very rapid growth in the spring. Fertilize the pruned plant in late January or early February to encourage new growth and flowers. Use a fertilizer that supports flowering plants such as a rose fertilizer blend or other fertilizer for flowering plants. You can see from this picture that new growth is beginning to sucker from the base just like Lantana. Apply a fertilizer near the base of the plant close to a source of water. Use the same fertilizer as the Lantana. A rose type fertilizer is fine. Oleander will regrow very quickly when cut back close to the ground, fertilized and watered. This was one month after pruning. Nitrogen in the fertilizer will push leaf and stem growth along with dark green color. Phosphorus in the fertilizer will push flower growth and flower size.             Oleander is pruned at the same time of year as lantana because it also blooms on new growth, not older growth. You can chose to remove 1/3 of the plant by cutting these largest stems to the ground for renewed growth at the base or you can cut the entire plant to the ground and let it regrow. Your choice. Either way you will see luxurious growth and lots of flowers next year. Again use a fertilizer that supports flower growth and apply it early in the spring. This is an example of a fertilizer that will push leaf and stem growth and dark green color. You would apply this immediately after pruning and water it in. A 10 pound bag sells locally for $7.95 This is an example of a fertilizer that it increases the number of flowers and their size. It should be applied about 4 to 6 weeks later. A 10 pound bag also sells for $7.95 .

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Nopal Cactus Talk Thursday, Dec 3 Lorenzi Park

1 Comment / edible cactus, nopales, nopalitos, tunas /

Mexicans call them Nopales or Nopalitos. The fruit they call Tunas. These edible cacti were under evaluation at the University Orchard in cooperation with the University of Sonora in Hermosillo. Fruit or tunas of the nopal cactus under cultivation and evaluation at the University orchard I will be giving a presentation to the Cactus and Succulent Society on how to grow them as a food crop Thursday night, December 3, at 630 pm at the Garden Clubs building located at Lorenzi Park off of Washington and Rancho. Nopal cactus ..nopales…under cultivation and evaluation at the University orchard. This is an ideal size and thickness to use as fresh vegetable.

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Apple Variety Testing for the Mojave Desert

Leave a Comment / Mohave Desert, recommended fruit for the mojave desert /

Q. I’ve seen Yellow Newtown Pippin listed as Under Review in your recommended fruit varieties to grow in the desert. How has it done? I would love to have one if the quality is good here. A. Here is a link to the recommended fruit variety list that I completed back in 2010.  http://xtremehorticulture.blogspot.com/2015/11/special-fruit-tree-orders-no-longer.html Apple Babe from Dave Wilson Nursery under evaluation in North Las Vegas Nevada Fuji apple grown in North Las Vegas Nevada Anna apple grown in North Las Vegas Nevada When I left the University back in 2011 this program of fruit evaluation for desert environments was no longer continued. Fruit quality is very connected to the terrior or the local environment. This is nothing new and has been noted for many other crops where quality is a desired trait and useful in marketing. I have not had a chance to evaluate this Apple yet. I like about five seasons of production to get a good evaluation. Just because a plant grows does not necessarily mean the fruit quality is high. Sometimes there is little you can do to influence the quality of a fruit if you do not have a suitable terrior it.  Most people think that a good fruit is one that is large, has an appealing color and free from blemishes to be a “good” fruit. How wrong! There are too many variations because of the climate and weather. The chilling requirement is 800 to 1000 hours according to Dave Wilson Nursery. This may be somewhat problematic for production in the warm desert but not necessarily for fruit quality. I will take a look at some of the information the orchard has gathered so far on this variety and let you know. I have not been involved so I hope that the three is still there, there are replications to account for variations and data has been recorded. It ripens a little bit before Granny Smith and a month or so before Pink Lady. It ripens during a time of the year when flavor should be good considering ONLY the time of year.  More information on this and related varieties.

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Why Did My House Plant Suddenly Begin Wilting?

2 Comments / houseplants, Wilting /

Q. Suddenly, this plant started drooping and weI can’t figure out why.  It’s was a beautiful healthy plant until about a week ago when the branches started to bend/droop. We tried tying it up but this morning it was even worse.  Could the heat being on in the house be a factor?  We’ve had the plant for about seven years with no problems. Two other possible factors:  about a month ago we moved the plant from an inside wall to an outside wall near two windows; and about four months ago we re-potted it using a regular mix. Plants that are drooping are wilting inside the house A. I don’t believe anything that happened a few months ago would have any direct bearing on this drooping. It has to be something that happened recently or that has been progressive. I’m assuming you’ve monitored the soil for moisture content by either using the pencil method or lifting it to determine its weight before irrigating. My guess is the problem is at the root level or major stem or stems coming out of the soil. I’m guessing the roots. I would pull the plant out of the container as if you are repotting it. Remove the soil from around the roots and inspect the roots for damage. It is difficult to find repotting soil that is not free from fungus gnats. If there are insects feeding on the roots than this could be the problem. If the soil is not draining like it should and root rot becomes a problem, then you would see this kind of reaction. I would repot it with a good potting soil, stake it, add some super thrive (I am not a big believer but at this point I would try anything) and see what happens. Inexpensive soil moisture meter. Not terribly accurate but gives you a general idea if the soil is wet or not. Monitor the soil moisture content carefully with a soil moisture meter you can get from the nursery for about eight dollars or use these other methods I mentioned to determine soil moisture content before you irrigate.

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Correcting Oleanders with Leaves Browning Along the Edges

Leave a Comment / drought, Oleander leaf scorch, over watering, salinity /

Q. We have one oleander approximately 2 years old and 4 new ones we purchased several weeks ago.  The older one (1st photo) and one of the new ones (2nd photo) have some leaves that are browning along the edges while the centers are still green; a few have tips that are browning too.  From what I’ve read, could the plants have leaf scorch or, “salt or boron toxicity”? Two pictures sent in regarding oleander leaf scorch A. You are right, this browning along the margin of oleander leaves, or leaf scorch as it is sometimes called, could result from a number of things. One possibility is a bacterial disease that has been called Oleander Leaf Scorch. It is a bacterial disease which is rarer in plants than fungal diseases. This disease is carried from plant to plant by what we call “vectors”. These vectors can be insects that feed on the “juices” of this plant or they can be transmitted by humans on pruning shears. This is why I am constantly reminding people to clean and disinfect their pruning equipment before they begin pruning and between plants if the plant they finished pruning appears to be “sick”. More information about oleander leaf scorch from the University of California Leaf scorch can also because to buy a lack of water and excessive salts in the soil which can be made worse if plants do not get enough water. One particular salt that you have identified as a problem in our soils is boron. The other particularly troublesome salts contain sodium and chlorides. Salts that contain for plants, such as nitrogen, phosphorus, potassium and others can also cause leaf scorch if they are in excess. Fertilizer salts containing high levels of nitrogen can be particularly troublesome and cause plant damage if applied in excess, too close to the plant or when soils are dry. What to do? Apply compost around the base of the plant and either wash it into the soil or lightly dig it into the upper surface of the soil. Add more water. If you feel as if the plant is not receiving enough water, add more drip emitters. This is preferable to just increasing the number of minutes since everything watered by that valve will be affected. If you’re fertilizing the plants, make sure the fertilizer salts that you apply are kept at least 12 inches from the trunk and applied near the emitters or bubbler. Make sure the soil does not become dry between irrigations because dry soils increase the concentration of salts already in the soil. Lastly, cut the oleanders to the ground and let them re-grow from the base. If you apply more water, improve the soil and are careful with fertilizers and the plants still have leaf scorch during the next growing season, then dispose of them and to get new ones. Oleander leaf scorch will not be in the soil. It can only be transmitted from unhealthy plants to healthy plants either by insects or humans who are not careful about pruning.

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