Xtremehorticulture

Xtremehorticulture of the Desert

Urban Agriculture Pays Off

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New research from collaboration between Arizona State University (ASU) and Google provides an assessment of the value of urban agriculture and the benefits it provides on a global scale.   “For the first time, we have a data-driven approach that quantifies the ecosystem benefits from urban agriculture. Our estimates of ecosystem services show potential for millions of tons of food production, thousands of tons of nitrogen sequestration, billions of kilowatt hours of energy savings and billions of cubic meters of avoided storm runoff from agriculture in urban areas,” said Matei Georgescu, an ASU associate professor. Using the Google Earth Engine, the researchers analyzed global population, urban, meteorological, terrain, and Food and Agricultural Organization datasets to arrive at their global scale estimates – and then aggregated them by country. The estimated value of four ecosystems services resulting from existing vegetation in urban areas was found to be roughly $33 billion. This includes a projected annual food production of 100 to 180 million tons and energy savings of 14-15 billion kilowatt-hours. Read more about it here

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Fertilizing Fruit Trees Class January 26 & 27

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Learn which fertilizers to apply and when, whether organic or mineral. Learn how to correct leaf yellowing, improve growth and fruit production on all fruit trees including citrus.Topics covered include applying mineral and liquid fertilizers, tree stakes, injectors, and selecting the right fertilizer including micronutrients. Where: Ahern Orchard, 700 Clarkway near Bonanza and MLK Time: 9am to Noon Cost: $10 plus tax  https://www.eventbrite.com/e/applying-fertilizers-to-fruit-trees-tickets-42153109084?ref=estw

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Calendar of Operations for Fruit Trees in the Eastern Mojave Desert

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I promised my friends at the last fruit tree workshop on pruning that I would publish a calendar of operations for fruit trees in the Eastern Mojave desert climate. This is at a 2000 foot elevation. Elevations lower than this will be earlier and elevations higher will be later. It is up to you to make some adjustments but I will post something about what the fruit trees are doing so the calendar can be shifted to a different calendar date. These are not exact dates but can vary two or three weeks either way. December – January. Fruit trees have no leaves  Dormant winter pruning  Pruning of the trees including any major structural changes including removal of limbs with saw or loppers and hand shears. Sharpen and disinfect pruning equipment at the start of each pruning day. More often if diseases are suspected. Winter insect control Spray oil application to fruit trees for prevention of outbreaks from aphids, scale insects, mealy bugs and spider mites.These spray oils are marketed under several brand names including Horticultural Oil, Horticultural Oil Spray, Dormant Oil, Ultra Pure Oil, Dormant Spray, Dormant Oil Spray, and others.Two examples are below.Sprays are applied to the trees following label directions after pruning and include all branches and the trunk down to the soil. All weeds are removed. All fruit is removed from the tree and picked up off the ground.  Fireblight  Fireblight is a horrible bacterial disease that is commonly controlled through pruning or even tree removal in severe cases. If there was fireblight in fruit trees the previous year, you might see remnants of this disease while you are winter pruning of Asian pear, European pear, apple and quince. If suspected, disinfect pruning equipment BETWEEN each separate cut on the same tree. If severe, remove the tree. Immediately remove infected wood from the property. Fertilizer application – Two weeks before peach growth begins  Complete fertilizer mineral fertilizer application or compost application. Fertilizer stakes, fertilizer injectors, mineral fertilizers, guanos, fish emulsion, rich compost, many different fertilizers exist to use or put together your own concoction. Use last years growth to tell you how much to apply for the current year. Use mineral fertilizers or compost that you know is rich in nutrients Iron fertilizer application – Combined with a fertilizer application Apply iron fertilizers to the soil for season long control of yellowing due to iron chlorosis. Most iron fertilizers will work but the best all around iron fertilizer contains an iron chelate called EDDHA. March – May – Fruit trees have finished flowering and small fruit are developing  Limb Spreaders Limb spreaders are used to increase the angle of attachment of a small limb or branch to the tree. The best angle of limb attachment for growth and fruiting is about 45 degrees from horizontal. Limb spreaders can be used during winter pruning but there is a risk of splitting limbs and branches. These limbs and branches are much more supple and easier to bend to a 45 degree angle after new growth starts. Fruit Thinning Removal of fruit from peach, plum, apple, pear so that remaining fruit gets larger. Remove extra fruit when they are the size of a thumbnail. Summer Pruning Remove unwanted growth from fruit trees before this growth gets big. Redirects energy and nutrients into fruit production, helps keep fruit trees smaller and reduces the amount of winter pruning. May – First apricots and very early peaches are beginning to ripen Pheremone traps This is the time when the first pheremone trap for codling moth and peach twig borer (other insects if you have them and there are pheremones for them) are placed in the fruit trees to catch the first flight of these pests. Getting some insects under control very early will reduce populations of them later. First catches are used to time insecticide sprays for best control and reduced pesticide use (IPM). It can also be used to time the deployment of traps for mating disruption.  Fireblight  Fireblight is an insidious disease of Asian pear, many European pear, apples and quince. This is when this disease first appears if it was not present before this. Cut at least 12 inches below where it is visible. If the infected limb dies to the trunk, remove the tree. General insect control Patroling and inspecting fruit trees on a regular basis (at least once a week) and inspecting fruit and leaves (bottoms and tops of leaves) helps identify if other pests and diseases might be a problem. Harvest – May through December The rest of the year is focused on protecting what you are growing and harvesting fruit. This requires frequent tree inspection and watching for insects, diseases, irrigation problems, mulch renewal, borer removal, etc.

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Some Compost Can Be Used as a Fertilizer

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Q. If I make my own compost, can I use it instead of commercial fertilizers for grass, plants, trees, shrubs? Some composts, if they are rich enough in nutrients, can be used like a fertilizer. A. Yes you can. But please be aware that homemade compost is not consistent in fertilizer content and quality. This is because of variability of different nutrients in ingredients used to make the compost. However, compost is universally good, whether it’s commercial or homemade, when added to soils as a soil amendment. This is the fertilizer content of a compost supplied by a company I consult with. This particular compost contains a large amount of fertilizer for each cubic yard of compost. This compost would make an excellent fertilizer for plants. Other composts may not contain as much fertilizer as this one.             When using compost as a substitute for fertilizer, it is important to know its carbon to nitrogen ratio, in other words how much nitrogen fertilizer it contains. The nitrogen content of a compost is critical. High nitrogen content (low carbon to nitrogen ratio) makes compost “hot” and less of it should be used. If compost has a high carbon to nitrogen ratio (low nitrogen content), then more of it should be applied when substituting it for fertilizer When applying compost as a fertilizer for plants, it is important to keep the fertilizer away from the trunk of trees and the stems of soft, succulent plants. This type of application is okay for woody plants but vegetables and annual flowers should have the compost mixed with the soil before planting because of the high salt content from the fertilizer salts.             Commercial composts aim for a carbon to nitrogen ratio close to 20:1 or twenty times more carbon than nitrogen. As this ratio increases to 40:1, the nitrogen fertilizer content decreases. At a ratio more than 40:1, the compost is still valuable but it’s value is greater as a soil amendment rather than fertilizer.             The carbon to nitrogen ratio in homemade compost is managed through what is added to the compost mix before composting. “Woody” additions to compost like wood chips, sawdust and shredded newspaper (sometimes referred to as the “brown” component) increase the carbon to nitrogen ratio.             Additions of grass clippings, leaves of trees and shrubs, and vegetable scraps (referred to as the “green” component) lowers the carbon to nitrogen ratio and make it more valuable as a fertilizer.             Animal manure (think of it as a concentrated “green” component) is high in nitrogen and added to get the carbon to nitrogen ratio low and improve fertilizer content. If lots of different components are mixed together in the right proportions, green components are balanced with brown components, homemade compost has all the nutrients needed by plants.             The short answer is “yes”. But substituting a homemade compost for a fertilizer application varies from batch to batch depending on what was used to make the compost.

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Dieback of Mature Fan Tex Ash

Leave a Comment / dead branches, dieback /

Q. I was cleaning up the leaves from my Fan-Tex Ash tree and noticed that there was sap leaking from 4 different limbs of the tree.  Attached are some pictures.  The tree is about 18 years old.  Although the first picture shows a small number of leaves remaining, the tree has always has had a nice canopy of leaves including this past year.   The tree is in rock much, but it receives nutrients (24-8-16) from an in-line liquid fertilization system. Readers Fan Tex ash tree I did some on-line research and the sap could be caused by stress (not enough water) or some type of borer.  The tree receives about 30 gallons of water each time it is watered.  In the winter it is watered once a week, spring and fall twice a week, and in the summer 3 times a week.  Is it common for this tree to have borers or is this problem likely caused by insufficient water? A. The amount of water it is receiving sounds about right or possibly a little bit on the light side. It is definitely not being over watered. Your frequency of application also sounds about right seasonally. If this tree is surrounded by rock mulch then the amount of water applied may not be enough. Look at New Growth Look at how much new growth occurs every year. At eighteen years of age the tree is in youthful maturity. The tree should be growing at least 8 to 12 inches minimum every year of new growth. If new growth is less than 8 inches every year then there is a problem. You are right in several things. It could be damage from borers. It could also be from stress such as a lack of water. Ash Decline Disease Fan Tex ash is an Arizona ash. Arizona ash has a problem with ash decline disease. For this reason, I no longer recommend planting any of the Arizona ash trees including Fan Tex. The tops of the trees could have developed ash decline even though this look is not typical of ash decline.  Ash decline usually hits one or two branches at a time and causes dieback and slow growth and leaves scorching. It is also possible it has sooty canker disease. Borers are usually associated with sunburn of limbs lower in the canopy. If this tree were topped with a chainsaw it is possible that any of these three possibilities could be a problem. Dieback of ash due to Ash Decline A severe case of ash decline on Modesto ash If this is ash decline disease, the tree is a goner and it will continue to slowly decline in coming years. I would recommend that it would be removed. If this is borers or sooty canker disease then some pruning might help it recover. If you decide to keep this tree, I would have a qualified arborist selectively remove the damaged parts of this tree. Certified arborists know how to prune trees and improve their ornamental value. Fertilizer Injector It is nice to know that these trees are getting part of what they need through an injection system that deliverables mineral fertilizers. Rock Mulch This is only a partial solution to successfully growing ornamental trees in desert soils. If these soils are covered in rock mulch then the soil is probably low in organic content. The organic content can be very important to ornamental trees growing in desert soils. Rock mulch causes desert soils to slowly become less and less organic over the years. Mineral fertilizers will not solve this problem. Either covering the soil with woodchip mulch that decomposes or continually adding compost to the soil will work. As this soil becomes more “mineralized” over time the tree may continually decline. If the soil is covered in rock mulch, add compost to the top of the soil and water it in. You would do this once a year for the next three or four years but it is a slow soil improvement process. This is all hinged on whether you have rock mulch or not. The faster option is to make vertical holes with post hole diggers throughout the root area of the tree and backfill these vertical holes with compost. This gets the compost mixed into the soil much faster and produces faster results. If this turns out to be borers than applications of systemic insecticides may be her only solution to the problem. In any case, someone needs to make a decision about what the problem is which determines the course of action.

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Are Organic Fertilizers Really Organic?

1 Comment / biosolids, compost, landscapes, lawns, Organic fertilizers, turfgrass /

The organic movement has a foothold in the turfgrass and ornamental industry. The same industry brewing for decades in home vegetable gardens, and then with small-scale producers, has emerged as a significant market percentage for commercial landscapers. Homeowners are asking for “organic” landscape plants, organic methods of controlling pests and applications of “organic” fertilizer to their landscapes. Migration of Organics to the Landscape Industry             Alternative methods for producing and maintaining ornamentals and turfgrass have been around for a long, long time. In the past, very few residential clients were willing to pay for the additional costa associated with the product. That may be changing thanks to local food movements and organic agriculture1. The word “organic” has become synonymous with “wholesome” and “safe”. Organic fertilizers for vegetable gardens             Organic has a different meaning in landscape horticulture industry. Organic can mean sources that are not synthetic or conventional. Organic amendments, such as municipal and animal sources of biosolids, can be applied to improve soil physical and chemical properties which in turn can improve turfgrass establishment rates, growth, and quality. We know, for instance, that in poor or marginal soils the incorporation of compost improves soil properties, increases soil nutrients and consequently improves plant growth. In soils with a naturally higher percentage of organic matter these improvements are less noticeable. Nitroform urea used in the landscape industry could be classified as an “organic” fertilizer even though it is manufactured  Composted Dairy Manure Reduced Turfgrass Disease in Colorado             Research at Colorado State University evaluated the effects of applying composted dairy manure as topdressing to Kentucky bluegrass. Researchers applied compost at the rates of 13.3, 26.6 and 40 cubic yards to the acre. Applying composted manure as topdressing to established bluegrass in 2003 through 2004 improved the soil’s physical properties and nutrient content. EZ Green Is a composted chicken manure product for the landscape industry that is OMRI listed product for the organic program by USDA             Although nothing new, the application rates are important. The two higher rates improved turfgrass overall quality and allowed the grass to retain color in the fall, early winter and green up faster in the spring. Not bad for a product that is not considered a fertilizer.             During the hot summer months the two higher application rates produced about 50% more clippings. The researchers concluded that compost improves turf quality and shoot growth via its action as a slow-release fertilizer. Lawn clippings remove from the grass and left on the curbside for dumping in landfills. These clippings are filled with valuable nutrients that could be returned to the lawn resulting in one less fertilizer application each year.             More turfgrass clippings sound like a potential landscaper’s nightmare but there is a positive side to this “problem”.  Increased amounts of clippings in summer months helps suppress the incidence of hot weather diseases. Infected leaf blades are removed through regular mowing and mulched back into the turfgrass sward or removed from the property.             Disease suppression by composts, composted biosolids and compost teas in vegetable crops has been documented fairly well. But research has been conducted on the suppressive effects of composts, such as biosolids, on turfgrass diseases as well, dating back 20 years or more. Compost tea applicator used for soil applications             This research shows promise to “organic” gardeners by reducing the application of fungicides, synthetic fertilizers and other chemicals to home lawns. Composts show promise in controlling turf diseases such as Pythium, summer patch, brown spot, dollar spot, red thread, necrotic ring spot and others.  Reductions in the applications of pesticides such as fungicides, directly supports the “organic” movement whether it is truly organic or not. Lawn clippings from commercial properties represent a huge amount of fertilizer that is removed from the lawn grasses and buried in landfills. Composted Biosolids Benefits To Landscapes Shown by Texas Researchers             Researchers at Texas A and M University, from 2005 through 2008, demonstrated the benefits from composts used for soil improvement and nutrient enrichment can be transferred from the sod farm to newly established landscapes. Previous studies with sod that recycled manure-based soil amendments as topdressing indicates that 77% of the phosphorus and 47% of the nitrogen might be removed and transported in a single sod harvest.             About one quarter of the cubic yard of composted biosolids was incorporated to rootzone depth in a cubic yard of native soil when establishing Tifway bermudagrass sod. Researchers measured that five times more nitrogen and seven times more phosphorus was available to turfgrass grown in biosolids compared to grass grown without biosolids. Fertilizer content of composted biosolid product by a local Las Vegas supplier             After two sod harvests, all of the nitrogen and phosphorus applied from the biosolids was removed with the sod. These nutrients were transferred, with the sod, to the landscape.             Although not demonstrated, researchers claimed that this could result in faster establishment times and better turfgrass cover in a shorter period of time. This, of course, would reduce the amount of fertilizers needed during sod establishment. Another coup for the organic movement.             They also found that sod established with biosolids was lighter in weight than sod grown without biosolids. Biosolids-grown sod contained more water but less native soil than sod without biosolids. This helped preserve the native soil. Less fuel is needed for transporting the sod. Organics, are you listening? Composts Release Fertilizer Nutrients Slowly             Composts, when used as a fertilizer, releases nutrients slowly, acting like a slow-release fertilizer. When establishing turfgrass in sod farm operations, rapid turfgrass establishment is important so a rapid release of nutrients, particularly nitrogen, is needed.             This was not going to happen with compost-amended soils. So the researchers applied either 50 or 100 pounds of nitrogen per acre at the time of sprigging (establishment) to supplement the slowly-released nutrients contained in the compost.             Because of the application of supplemental nitrogen, the time between harvests in biosolids-amended soil plus fertilizer was reduced 60% compared to

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Lemon Not Meyers, Remove Fruit?

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Q. My lemon is not a Meyers lemon but the tree is starting to flower. I didn’t want to pick them this early because they are still getting sweeter. Does the “remove lemons before the tree flowers” rule apply to this variety as well?  Ponderosa lemon ready to pick on the left and immature on the right. On the tree at the same time. Rough lemon grown in Las Vegas A. Yes it does. It applies to all fruit trees. Try thinking like a lemon tree. The reason the tree produces fruit is to reproduce. When the fruit drops to the ground, the fruit rots and releases nutrients that feed developing seedlings.             The tree “knows” if there is fruit attached to its branches or not. It can’t see anything but there are other types of communication that trees have perfected. When the fruit has been picked, the tree “knows” the fruit is no longer there.             The reason for picking fruit before the tree begins flowering is to send “signals” back to the tree that it no longer has fruit attached to its branches. When fruit is missing, the reproductive or flowering cycle of the tree is encouraged.             The beginning of flowering is the beginning of the reproductive cycle. The normal flowering cycle of trees is at certain times of the year. If this time for the normal flowering cycle to begin has passed or is delayed, the tree may not flower at all or flower very lightly. Lemon turning yellow but hasn’t quite got there yet. The color change can happen faster in the presence of ethylene gas. Ripening bananas give off lots of ethylene gas and can be used to improve coloration of citrus.             You are right. Most citrus are considered non-climacteric, or, in other words the fruit doesn’t increase in sweetness after it is picked. It is best to wait when picking lemons to improve its sweetness, but you don’t want to leave it on the tree long enough to interfere with flowering.             Other fruit which don’t ripen or ripen little after picking include figs, grapes, pomegranates, cherries and apples. As a consumer this means the sweetness of non-climacteric fruit does not increase much, if at all, after picking.            If citrus is left too long on the tree fruit quality is reduced because it becomes “pithy”; it starts drying out. Remove all fruit from trees before they begin their next flowering cycle.

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