Xtremehorticulture

Xtremehorticulture of the Desert

Should We Keep Politics Out Of Gardening?

1 Comment / how can you reduce the temperature on a cinderblock wall, reducing the heat from block walls, Tomatoes and heat /

I’m not so much asking a question as telling one of my solutions. My garden is along an East facing concrete block wall and though shaded in the afternoon there is still considerable heat coming off it during the summer.   Add caption Two years ago I stopped someone picking up election signs and asked if I could have some.  They said yes and I got enough to do most of my garden.  Through procrastination and adult life I didn’t manage to get them onto the wall until late June.  My tomatoes were growing OK but they were leaning away from the wall and you could really feel the heat when close to the wall.  I mounted the signs on the wall to kinda insulate it from the sun in the hopes of reducing that reflected heat.  It worked really well as within two weeks the difference was noticeable.  The plants had started growing more upright and appeared to take on a new life.  This year I got some more and expanded the coverage to the entire garden.  Took less than two hours and I’m hoping it helps to grow a bumper crop of tomatoes. Pictures attached hopefully.  You can use all of this if desired but please, no name or e-mail address.  Thanks. Now if I could just figure out what’s wrong with my peach tree I’d be set.

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Prune Grapes to Improve Production

3 Comments / How to prune grapes, how to prune table grapes, how to prune wine grapes /

Our climate in the Mojave desert can damage grapes during the cold winter months. This winter was warmer than usual and the two times it dropped into freezing weather this winter was when plants were deeply in their winter slumber. That’s good. Freezing weather occurring early in the fall or late spring is typically more damaging than the same freezing weather in midwinter. For small-scale producers and backyard gardeners I like to tell them to prune their grapes last. Wait until the most brutal part of the winter is over and then prune. The reason for this is simple. When we prune grapes we typically remove everything on the plant that is not necessary. When we are finished pruning we leave behind very short Spurs or longer canes depending on the variety of grape. Regardless, for good production we need everything that we have left after pruning to be alive. Temperatures in the Mojave desert can drop to temperatures that can damage grapes. If we prune grapes too early and this is followed by very cold temperatures, we can lose some and possibly most of our production because of the death of these spurs or canes due to cold. Here are some tips on pruning table and wine grapes: 1. When you prune grapes and the temperatures are warm, grapes will bleed. That is, you will see water coming from the cuts. This is normal. This is water being pumped up the vine by its roots in preparation for spring growth. They may continue to weep like this until growth starts and the leaves suck this water away from the cuts and the cuts have a chance to heal. 2. Identify all of the growth that occurred last year. This will be a different color than the older growth or it just will not look as old. Once you have identified last year’s growth, you can cut all of them back so that the new growth is about 18 to 24 inches long. These long canes are where your grapes are going to be produced. 3. Space these long canes which will produce grapes about 12 inches apart. You want to do this for table grapes because this will encourage the berries to become larger. You want to do this two wine grapes because you want to concentrate the flavors developed by the plant into fewer berries. Choose healthy and vigorous canes to be your producing canes. Identify any canes that are between your producing canes. You can either remove these or them back and remove all of last year’s growth. If you remove a cane, you will remove the fruit. Grape pruning progression for spur pruned grapes. Cane pruned grapes are justlonger spurs. 4. The remaining canes will be cut back to about an inch long (spur pruned) or about 12 inches long (cane pruned). If you want to get technical, identify the buds on the canes. When spur pruning, leave only one to two buds remaining. When cane pruning there should be 10 to 12 buds remaining. 5. If you have Thompson seedless grapes, or Black Monnuka do not spur prune them. These should be cane pruned. Make sure you have 8 to 10 buds present on the cane when you’re finished cutting.Most other table grapes are spur pruned. Most wine grapes for our climate are also spur pruned. Here are some previous posts on my blog concerning pruning grapes. http://xtremehorticulture.blogspot.com/2012/12/how-to-prune-table-grapes.html http://xtremehorticulture.blogspot.com/2013/03/spur-or-cane-prune-my-grapes.html http://xtremehorticulture.blogspot.com/2011/10/maxwell-norton-gives-table-grape.html

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How to Control Whiteflies on Tomato This Summer

Leave a Comment / Controlling white flies, how to control whiteflies /

Whiteflies on the bottom of pomegranate leaf Q. I am new to gardening in the desert and am surprised at my success thus far!  That is, until the white flies came.  They showed up on the grapes and zucchini first, maybe in May or June.  Unfortunately, I didn’t think they would become a problem. By August they had attacked everything! I pulled broccoli plants and found I needed a mask to keep from inhaling them! What can I do this season? A. Whiteflies are a very tough to control once they get established in the numbers you are talking about. They are much easier to control if you’re diligent about controlling them when you first see them. Females lay a couple hundred eggs at a time and these become adults that can lay more eggs in about six weeks. This means you can have exponential growth in their numbers if they are left undisturbed in six weeks. Whiteflies, like so many garden pests, do not show themselves but remain hidden. Unless you stoop over and turn over leaves and look at their undersides, you will not know they are there until you see their telltale signs of plant damage. Signs of damage are yellowing and scorching of older leaves, sticky residue on upper leaf surfaces of lower leaves and ants. Bottom leaves of sunflower yellowing and scorching due to past problems on the bottom side of the leaves. Photo courtesy Viragrow. Ants love the sticky residue that whiteflies and aphids produce. Ants climbing on plants in the garden or on fruit trees is a very good sign you have a developing pest problem. Backpack sprayer suitable for vegetable and Orchard spraying If you buy transplants to put the garden, spray the undersides of the leaves and the stems with insecticidal soap, neem horticultural oil. Once the transplants have been placed in the garden and they have grown a little bit, remove the bottom leaves of transplants that are within a couple inches of the soil. These bottom leaves are perfect hiding and living quarters for many of the problem insects. They are so close to the soil surface they can’t be sprayed effectively. Stay away from conventional garden insecticides unless this past really gets out of control. Whiteflies are resistant to many conventional pesticides and these traditional pesticides can knock out whitefly predators that help keep them under control. Get yourself a decent compressed air garden sprayer such as Solo or Chapin and use soap and oil sprays in rotation with each other. Early in the season when it is still cool, check the undersides of the leaves and look for critters. Weekly applications are probably enough during cool weather. When it starts to get warm, inspect the bottom sides of the leaves and spray twice a week. Make sure you spray the undersides of the leaves. That’s where these critters are! Control ants that are getting into the garden. They are buddy buddy with aphids and whiteflies. Ants come from a nest in the ground. Follow their entourage back to the hole in the ground and treat around the hole with a bait that they can carry back to the nest. These are the most effective for ant control. If you see bottom leaves that are starting to get yellow, pinch or clip them off. If they started to turn yellow they are contributing to the plant anymore. Look at the underside. There are probably critters feeding away. Removing these leaves, removes pest problems.

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Fertilize More Often For High-Quality Roses

Leave a Comment / how often should I fertilize roses, what is the best fertilizer for roses, When should I fertilize roses /

Q. I’d like to continue fertilizing my rose bushes right through the spring since the past year’s bloom was not too impressive. Is there any advantage or harm with that strategy? A. High quality roses are typically fertilized about every 6 to 8 weeks through the winter, spring and early summer in our climate. Fertilizer applications are usually stopped during the summer months when flowering is the worst and resumes about a week before good flowering resumes. SulPoMag conttains magnesium and canbe substituted for epsom salts Fertilizer applications are made to support healthy, vigorous growth and flower production. The timing of these applications varies with the type of rose and variety as well as the microclimate. Generally speaking, roses perform very well in our climate for about 8 to 9 months of the year. Microclimates that are warm and protected in the winter may support the flowering of roses through the entire winter. In these microclimates you would fertilize all winter long. In cooler microclimates you may see an interruption in flowering during the winter but have a longer flowering period in spring and fall. Fertilizer applications would support roses during their flowering periods. If you are fertilizing roses more often, then use smaller amounts of fertilizer or use fertilizers that release nitrogen more slowly. Make sure that your roses receive an annual application of iron that is applied just prior to new growth. Many rosarians like to apply Epsom salts as part of their fertilizer regime for the magnesium contained in it. Other fertilizers like SulPoMag and some palm fertilizers also contain magnesium and may be an appropriate substitute.

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Crazy Roots of Tomato Is Due to Nematodes

3 Comments / bumps on tomato roots, how to discourage nematodes, Root knot nematode, what will grow with nematodes /

Q. I was going through my garden notes and I found pictures I took a few months ago of my tomato plants.  A few of them came up with real gnarly roots, I have never seen anything like it.   A. This is definitely root knot nematode judging from your photos. There really is no way to totally rid the soil of nematodes. In the past, soil fumigants were used on a regular basis to knock these critters back. Soil fumigants are being eliminated from the pest control arsenal due to environmental concerns. Your options are to move your growing area to a new location that is not infested, grow in raised beds or containers and use resistant varieties. There are some vegetable varieties more resistant to nematodes than others. Roots of tomato plant from reader Use varieties that have a capital “N” after their name. This stands for “nematode resistant”. An example would be the tomato, Better Boy VFN which is resistant to Verticillium and Fusarium diseases as well as nematodes. Build up your organic matter content with lots of compost. Nematodes don’t like soils with high organic matter. Be very careful of transferring soils contaminated with nematodes to new beds or containers. This includes using contaminated gardening utensils. Make sure utensils are sanitized between locations. It is possible for this pest to migrate from your existing soil to a new raised bed constructed on top of contaminated soil. You might to consider laying thick plastic underneath the raised bed. Make sure the plastic is sloping slightly for drainage and make the bed at least 12 inches deep. Here are some links back to my blog where I have written about nematode in the past. http://xtremehorticulture.blogspot.com/2013/03/use-plants-resistant-to-nematodes.html http://xtremehorticulture.blogspot.com/2013/12/nematodes-permanent-garden-problem.html http://xtremehorticulture.blogspot.com/2011/07/twisted-and-distorted-tomato-roots-may.html http://www.reviewjournal.com/columns-blogs/bob-morris/nematodes-are-manageable-never-go-away

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Shoestring Acacia Height Can Be Lowered

1 Comment / how to lower the height of shoestring Acacia, Pruning shoestring Acacia /

Large shoestring Acacia. Some are more upright than others while others are more rounded. This is because of how they were propagated, grown and location. Q. I have a tall (40-50ft) shoestring Acacia tree that is too close to the house. The leaves accumulate on my flat roof and clog the scuppers. This has caused interior flooding on occasion as the water overwhelms the vents and skylights. My question is, can this tree be topped or does it need to be removed. A. Yes, you can reduce the height of this tree. There is a pruning technique to lower its height called “drop-crotching” which is very different from topping. Topping is extremely damaging to trees while “drop-crotching” lowers the height of a tree while maintaining the tree’s form as much as possible. This shoestring Acacia was topped. This is NOT how we want to lower the heights of trees. The method we are looking for is called drop crotching. Most likely the reason it had to be lowered is because the signage was blocked. This was the fault of the designer or landscape architect. Topping was the fault of the tree butchers.             Very large trees cannot be reduced in size to very small trees. There is a limit how much a tree can be reduced in size by drop-crotching. When lowering the size of very large trees dramatically, reduce their size over a period of several years rather than doing it in one season. This is not the same tree but it was done by the same pruning crewon a tree close by.. These cuts were made in the wrong locations on the tree with absolutely horrendous care. When drop-crotching a tree you need to find very specific spots to cut where the form of the tree is not totally destroyed. You would first identify the vertical branches providing the most height. Trace these vertical branches to lower side branches. Remove the vertical branches just above the juncture with the side branches. You would repeat this at all of the locations that contribute to its unwanted height. By pruning in this fashion, you will retain as much of the trees natural form as possible. A guide to drop-crotching can be found http://pubs.ext.vt.edu/430/430-458/430-458.html If drop-crotching is not acceptable then removal is the only other option. Related post http://xtremehorticulture.blogspot.com/2013/05/can-i-prune-my-shoestring-acacia-now.html

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White Crust on Soil Surface Is Alkali or Salt

Leave a Comment / how to remove salt from soils, What is white deposit on the soil surface /

Q. I dug up some of our native soil and amended it with 50% planting mix. The next day after it dried, this white substance appeared on the surface. Is this salt or alkali? I know my soil will effervesce when you pour vinegar over it. Salt deposit left on soil surface of the readers soil. A. Salt and alkali are pretty much the same thing. Alkali should not be confused with alkaline. Alkaline refers to pH. Alkali refers to salts. Soils that create bubbles or effervesce when vinegar is applied to them have quite a bit of calcium carbonate, or lime, present. Salt deposit left on drip emitters The old-timers who grew things in desert soils would refer to “white alkali” and “black alkali”. I think the word “alkali” has remained in our vocabulary, but not the difference between white and black types, and it is just as confusing now as it was then. White alkali refers to the white salt accumulation on the top of soils. These white salts were usually sodium sulfate, sodium chloride, and magnesium sulfate. Black alkali on the other hand left blackish spots on the soil surface usually composed of sodium carbonate and organic matter. It was understood that black alkali was more damaging to plants in soils than white alkali. Salt deposit left on soil surface after an irrigation In fact, when ranking these salts and their injurious effects on crops, sodium carbonate was considered the worst while sodium chloride (table salt) was somewhere in the middle and sodium sulfate the least injurious. When you had black alkali salts, many farmers would just give up and walk away from those soils. The salts in your picture look like white alkali. I would have to guess it is a mixture of salts containing calcium, sodium and magnesium and carbonates, sulfates and chlorides. You wouldn’t know unless you submitted the soil for a soil test. When salts accumulate on the soil surface it is best to take a flat-nosed shovel and scrape off the top inch or so and dispose of it. Then begin activities that reduce the salt content. Salt deposits left on block wall after water evaporates. Most salts are removed with water and flushing. Level the soil surface as much as possible. Sprinkle the soil with water to push the remaining salts deeper into the soil. The idea is to push the salts deeper than the roots of your crops. If the soil does not drain easily, there may be a high sodium problem. If this is the case, apply gypsum to the top of the soil and rake or rototill it in as deep as you can. Then begin your irrigations. Gypsum is used to remove sodium from the soil and replace it with calcium. Sodium is a bad player in soils and prevents drainage. Substituting calcium for sodium improves drainage. Also, mixing compost in the soil will help in the removal of salts and make them less injurious to plants. Learn more about salts, soil, water and irrigation of the desert http://xtremehorticulture.blogspot.com/2012/09/there-is-lots-of-salt-in-las-vegas.html http://xtremehorticulture.blogspot.com/2012/01/removing-white-salt-deposits-on-walls.html http://xtremehorticulture.blogspot.com/2012/01/lining-raised-bed-garden-to-prevent.html http://xtremehorticulture.blogspot.com/2014/11/how-to-clean-drip-emitters-that-are.html

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Mulch Recommendations for Fruit Trees

1 Comment / What kind of mulch should I use around fruit trees, why mulch fruit trees /

Q. Please provide me with recommendations for types of mulch for fruit trees. A.  By definition, mulches lay on top of the soil surface and are not mixed with the soil. There are organic mulches such as wood chips and there are inorganic mulches such as rock and plastic. Most mulches shade the soil surface, help to conserve water and reduce weed problems. Results in one year of fruit trees planted with and without surface wood mulch. Mulches made from wood decompose over time as long as moisture is present. Decomposing wood mulch enriches the soil. Rock, plastic and bark mulches do not. Their purpose is primarily to add beauty and reduce weed problems.In the case of plastic inches that are exposed to sunlight, they are intended to warm the soil early in the spring for faster route and plant development. Even if you have rock mulch, pull the rock mulch away from fruit trees and apply 3 to 4 inches of wood mulch in the an area as large as possible underneath the tree. Any wood mulch, not bark mulch, works well around fruit trees. The best kind is a mixture of different types of wood and decomposes in 2 to 3 years. You don’t want to use only bark mulch if your purpose is soil improvement. Decaying wood does take nitrogen from the soil but this is not a problem as long as trees and shrubs are fertilized annually. Wood and rock mulches help keep the soil cool, conserve water and reduce the work required for weeding. Only wood mulch enriches the soil. Rock mulch contributes to mineralization of the soil which means it contributes to the depletion of organic matter, it doesn’t add to it. Some of the best mulches for fruit trees are woodchips from a variety of trees but excluding trees with long thorns such as many of the mesquite trees, athel and salt cedar and palms. Palm trimmings decompose very slowly. Woodchips from trees with long thorns end up puncturing the bottom of a sneaker or vehicle tires. Just about any wood source will pose no problems including eucalyptus, cedar, and even oleander. An excellent mulch is also the residue left behind from stump grinders.  Plastic mulches are used primarily for vegetable production and should not be applied underneath rock or wood mulch for weed control. Never. Learn more about mulches http://xtremehorticulture.blogspot.com/2014/05/can-i-use-chipped-pine-for-mulch-around.html http://xtremehorticulture.blogspot.com/2014/06/wood-mulches-for-desert-soils-are.html http://xtremehorticulture.blogspot.com/2013/07/come-and-get-your-mulch-at-unce-orchard.html http://xtremehorticulture.blogspot.com/2011/07/apple-tree-planted-in-rock-mulch-q.html

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Pruning Globe Mallow and Bird of Paradise

Leave a Comment / desert bird of paradise, How to prune globe mallow, how to prune Mexican bird of Paradise /

Q. We have a very old globe mallow shrub that looks bad after a frost. When and how should it be pruned to bring it back to its former glory? Do Mexican Red Bird of Paradise need regular pruning? How can one tell what and where to cut? Globe Mallow growing in extremely poor soils in Las Vegas. A. Globe Mallow can be a spring flowering perennial which means it can live for over two years provided it does not get damaged. Growing in the desert without irrigation it can be rather scrubby. But with a small amount of water and fertilizer it can be a beautiful woody shrub that can grow 2 to 3 feet tall and 3 feet wide. Close close-up of the flower of globe mallow growing under stressed conditions. If the globe mallow is looking kind of old and ratty you can cut it down to an inch of the soil and totally renew it or you can selectively cut down some of the older stems and renew it slowly. If you want to keep it bushy from head to toe then take about one third of the oldest wood out now, next year take another third and the following year take another third. This will renew it over a three-year cycle and help keep the foliage and flowers from top to bottom. You would do this pruning immediately after it finishes flowering. Flower of the desert bird of Paradise Mexican red bird of paradise usually gets a pruning to the ground every few years because of hard freezes. You have a couple of choices, much like your globe mallow. You can cut it to the ground or selectively remove one third of the oldest wood to the ground and in a three-year cycle. You would do this pruning during the winter months or before new growth starts in the spring or after flowering is finished.

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