xtremehorticulture – Page 252 – Xtremehorticulture

Jeeesh. So You Want to Grow Magnolia in Las Vegas. Here’s How.

1 Comment / magnolia in the desert / xtremehorticulture

Q. I’m probably going to be at the mercy of the stock at the local nursery this weekend. I really liked the 24 gallon Magnolia tree they had but do you think my space of 18′ x 14′ will be too small for a Magnolia? Southern magnolia growing near Decatur and Red Rock in Las Vegas A. As long as you understand I am not endorsing the planting of a magnolia but if that is what you want, then read the following. Magnolias can get huge and so if you want to enjoy it for a few years and yank it out when it no longer does well, then go for it. You might get ten or more years before this happens. Do not put it close to a hot (south or west facing) wall. BUT you must plant in a hole that is three or four feet wider than the container. Mix good compost (bagged and good stuff will be expensive) half and half with the soil you take from the hole and remove large rocks (baseball sized or larger). Mix a fertilizer like 16-16-16 with this backfill; about one handful for each ten gallon bucket. Mix it all together and put this modified soil back into the hole surrounding the rootball of the plant. As you are putting this soil back into the hole, add water from a hose so it makes it the consistency of quicksand to get rid of air pockets and the slurry flows all around the root ball. Another Southern magnolia growing near Eastern and Harmon. Notice the dieback beginning in the top. Roots cannot provide enough water to the tops during mid summer and the low tolerance of this plant to temperature and humidity extremes. Plant at the same level as it was in the container. Water it deeply, three times, immediately after planting and when the soil has drained each time. It will be watered after planting best with something that can deliver a lot of water because this tree will require lots of water each time it is watered. The amount of water should be equivalent to filling a basin around the tree with three inches of water; if it is a 15 gallon plant then apply 15 gallons of water. You don’t have to use a basin but this basin idea should give you an idea of the amount needed. If you use drip emitters, then you should have initially at least three emitters for a 15 gallon tree. If it is a 24 inch boxed tree, then you should put at least at four emitters. As the tree gets larger, you will need to add more emitters and more water, perhaps one or two gallons more at each application per year of growth. Big trees use more water than little trees. Lastly, dig out an area around the tree that will allow you to put about four inches of wood mulch in an area covering a circle, at least eight feet in diameter, around the tree. The key with this tree is the right location, soil modification at the time of planting, adequate irrigations and wood mulch under the tree.

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The Truth About Deep Root Fertilization of Trees and Shrubs

12 Comments / fertilizers, how to fertilize trees and shrubs / xtremehorticulture

Q. Is deep root fertilization a good way to fertilize our African sumac tree, purple sage bushes and the purple plum tree? I’ve seen advertisements from some landscapers for this process. Where are the roots of trees and shrubs growing in a lawn? A. There is nothing special or magical about deep root fertilization from landscapers or done by yourself. If done properly, and many do not, the fertilizer is injected into the soil at the depth of the roots. This is usually only a few inches beneath the surface of the soil. Deep root fertilizer applications have made a name for themselves mostly where trees and large shrubs are growing in a lawn. By applying it beneath the surface of the lawn, high rates of fertilizer are applied without damaging or killing the lawn or causing the lawn to have dark green spots of tall grass where the fertilizer is injected. The rates of fertilizer applied is quite high so the “saltiness” of the fertilizer (all fertilizers are salts of some sort) would normally kill the grass if that fertilizer is applied directly to the lawn. These are the brown spots in your lawn that will occur if you drop fertilizer on one spot or place it too shallow under the lawn. It should be 6 to 8 inches under the surface. Also, lawn grasses are fertilizer “hogs”. Because of their fibrous root system they take fertilizer, nitrogen in particular, easily and quickly from the soil thus robbing it from deeper rooted trees and shrubs. By placing a complete fertilizer (one containing all three elements, nitrogen, phosphorus and potassium) several inches beneath the soil surface, it places the slower moving phosphorus and potassium right at where the roots are feeding. Commercial companies will usually use a liquid fertilizer and inject it with what is called a “soil needle” or deep root feeder. This is a probe that is connected to a tank on the back of a truck containing a fertilizer solution. A hose comes from the tank through a pump and, under high pressure, the liquid fertilizer is injected into the soil. Granular fertilizer placed next to a bubbler in wood mulch so the fertilizer will be moved to the roots by the water coming from the bubbler. Real fancy units will allow the operator to squeeze the handle on the injector (a probe with holes in it to allow the fertilizer solution to injected into the ground) and inject a precise amount of fertilizer solution with each injection. The operator can inject the soil in dozens of places under the tree very quickly an be on his or her way. You will know if they are doing it correctly by how deeply they push the injector. If they push it too deeply, the fertilizer will be placed beyond the plant roots and a large amount will be wasted. If they don’t push it deep enough and it is in a lawn, then you may have burn spots in the lawn. Burn spots are usually less of a problem in the winter months. You can do deep root fertilize your own trees and shrubs by using tree and shrub fertilizer stakes and pounding them into the soil beneath the soil surface a few inches. You can also do it by irrigating the lawn and, while the soil is still moist, pushing a shovel into the soil in spacings about two feet apart under the canopy. Fertilizer stake. The plastic cap is placed over the fertilizer stake so that it does not shatter when pounded into the wet soil under a tree near the source of water. The shovel is pushed into the soil all the way, pushed forward so that the slit cut by the shovel is open, and dropping some fertilizer into the open slit. You then pull the shovel out and push the slit closed with your foot. Irrigate immediately after you are finished. If your trees are in a desert landscape with drip irrigation then the whole idea of deep root fertilizer comes into question. When trees and shrubs are watered by drip irrigation then I would question whether deep root fertilizer applications are necessary. All the fertilizer will be “pushed” by watering from the drip emitters. Roots of trees and shrubs in a rock or desert landscape will not grow like they would in a lawn. Instead, with drip irrigation, roots grow profusely near the emitters and do not go “searching” for water or grow toward water. They are not psychics. With drip emitters is best to drop your fertilizer in slits next to the emitters or use tree fertilizer stakes at the emitters.

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The Birdsnest Mushrooms in Your Mulch – Kids Will Love Them!

16 Comments / compost, decaying, fungi, mushrooms, rotting, wood mulch / xtremehorticulture

Reader’s “pods found in the garden. All of these might nearly fit on a quarter to give you a rough idea of their size. Q. I figured I can’t let more than three months go by without pestering you with a question! Attached are two photos of some mystery pods I found in the garden when doing some clean up. One is with the pods closed, and the second is with them open and with what appears to be small black seeds. Any idea what this is? A. These are not pods at all but what is called birds nest mushrooms. These do look like tiny little pods with black seed like things inside them. Like other mushrooms or saprophytic (feed off of dead things) fungi they “feed” of off decaying organic matter in the soil. We can see these fairly commonly in compost heaps, decaying mulches or other places where organic waste is decomposing. They are interesting and kids love these little things. Unopened or just opening “pods” of the reader Nothing to worry about. They feed off of DEAD plants so no harm to living plants or you. They are decomposers so they help to break down litter on or in the soil after or during a warm wet period. I attached a fact sheet from Texas A and M on this interesting form of plant life. I will post your pictures on my blog for others to see them. Birdsnest and other inhabitants of wood chips and compost

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Science in Action: Part II. Designer Plants

Leave a Comment / crown gall, developing Bt, gene splicing, genetic engineering, gmo / xtremehorticulture

Designer Plants Robert Ll. Morris Genetic engineering has changed commercial plant breeding forever. In years past we always thought of obtaining new plants by simple breeding and hybridizing. But to get for instance elms resistant to elm leaf beetle or turfgrass resistant to Roundup these plants had to be permanently changed in ways that simple breeding and hybridizing had not been able to accomplish. The major limitation was that the plants had to be relatively close in their evolutionary history so that a transfer of new information from one plant to another by traditional breeding techniques could occur. All that has changed with genetic or bioengineering. Over the last twenty years scientists have discovered that all living organisms have genetic information that is interchangeable, even between plants and animals. Unlike traditional breeding, bioengineering has made it possible to select exactly the traits desired from nearly any living organism and insert them into a plant and create a genetically modified organism (GMO). In Part I we talked about how the bacterial disease, crown gall, played a role in bioengineering by providing a biological model for scientists to use to insert desirable genetic information permanently inside plants. It was known that the crown gall organism, a bacterium, could infect a plant and insert its own information causing the plant to do something it normally would not do. In the undesirable case of the crown gall disease, produce a tumorous swelling of plant tissue that housed and protected the disease. More on Crown Gall Disease Organism Scientists realized that packets of new, desirable genetic information might be inserted into plants following the same method that crown gall bacterium used. Early in the development of this technology the crown gall bacterium, modified with desirable genetic information, was used as the vehicle for transferring genetic information to plants. The crown gall model of gene insertion eventually led to the development of new more efficient technologies like “gene guns” which could “shoot” new information inside of plants. Terms like “gene splicing”, which scientists use to recombine genetic information inside plants in an attempt to bioengineer a new organism with more desirable traits, results in “transgenic organisms”. This is a term that can be daunting at first until it is realized that it just means an organism that was altered or changed as a result of new genetic information which was purposefully inserted by some method. More on Gene Splicing Transgenic organisms usually have some sort of benefit passed on to it from genetic engineering resulting in an economic benefit to the horticulturist and ultimately the consumer. These might be new plant traits such as improved resistance to plant pests like viral yellows or ringspot diseases, acquired resistance to pesticides such as the Roundup Ready® line of crops, some dwarfing characteristics in agronomic crops like wheat, the preservation of food flavors such as in Flavr Savr© tomato lines, and improved resistance to insect pests by inserting genes from biological organisms that produce toxins poisonous to insects such as the bacterium Bacillus thuriengensis (Bt). Bt pesticide sprays for controlling insects have been available to commercial applicators and homeowners as a form of “natural” or “biological” pest control since the early 1960’s under a variety of different names. The first release of a Bt spray had a very narrow range of insects that it would control. Larvae of moths and butterflies with an alkaline gut pH and that fed largely on leaf surfaces were the only targets. This narrow range in pests that it controlled was both good and bad. It was good since it was very safe for humans and other animals that weren’t larvae of moths and butterflies such as beneficial insects. It was bad since it controlled such a narrow range of insects and these only in their larval stages. We now recognize this particular strain of Bt as the variety kurstaki. Since the 1980’s there have been 50 strains of Bt developed that are specific to not only moth and butterfly larvae but larvae of other insects such as the elm leaf beetle (Bt var. tenebrionus), fungus gnats (Bt var. israelensis), and a wide range of agricultural pests including beetles. All the different Bt’s had the same basic scenario however; the susceptible juvenile insect eats plant foliage that has the bacterium on its surface, Bt spores are ingested by larvae, the spores grow and reproduce inside the insect producing toxins, toxins paralyse the digestive tract of the larvae causing it to cease eating, insect death. Death can range anywhere from a few hours to 5 days after ingestion. This depends on the amount of Bt ingested, the size and variety of the larvae and variety of Bt used for control. Bt became popular in the past because it had some distinct advantages over other pesticides: it had a low hazard to humans; there was no waiting period from time of application before re-entering the field; different strains of Bt didn’t harm beneficial or non-target insects; insects that died from Bt were not dangerous to predators; Bt was not known to cause injury to plants on which it had been applied and was not considered harmful to the environment; and, little or no insect resistance had been reported. More on Bacillus thuringiensis or Bt The major problem with Bt applied as a pesticide was its lack of persistence in the environment (sunlight and rain shortened its life) and it had to be eaten by the insects to work and only the larval stages of the insect were susceptible. Multiple applications needed to be applied with just the right timing or its chances of success were limited. But what if the Bt toxin could be inserted into the plant? The toxin would always be present so timing was not a problem. Persistence was not a problem since the plant protected and even produced the toxin. To insert the Bt toxin gene (lets call it X gene) the scientists first identify the right Bt. Next they

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Science in Action: Part I. Engineering Plants Using Crown Gall Disease

Leave a Comment / crown gall, gene gun, genetic engineering, Monstanto / xtremehorticulture

Science in Action: Part I. Engineering Plants Using Crown Gall Disease By Robert Ll. Morris Ever since Mendel discovered that characteristics in pea plants could be inherited, scientists have been improving plants through hybridization; two related plants were crossed and the resulting offspring had characteristics of both parent plants. Breeders then selected and reproduced the offspring that had the desired traits. These conventional plant breeding techniques were relatively imprecise because they shuffled thousands of genes around and distributed them to the offspring just to get one important change in a plant that was economically worth pursuing. One challenge encountered in Mendelian breeding is that generally only closely related species of plants could be crossed. If no closely related species with desirable traits existed, breeders had no way of passing on these traits to the other plant. Another problem was that some of the genes were linked to each other. This is seen today in tomatoes that have been bred so that they can be shipped long distances but with a substantial loss in flavor. Since the early 1980’s scientists have been using the tools of modern biotechnology to insert a single gene, or just two or three genes, into a plant giving it new, advantageous characteristics. With this technology a single gene could be inserted into a plant giving it a desired characteristic instead of the mixing all the genes from two plants through traditional plant breeding and hoping for the best. This technique could develop a new plant with much more control and precision and at a rate much faster than ever before. The bioengineering of plants emerged from discoveries by researchers in previous years on how bacteria caused plant tumors, how viruses protected plants from other viruses and what enabled some bacteria to kill insects. Some first major step toward biotechnology occurred early in the twentieth century with a plant disease called crown gall. Crown galls are tumor-like plant growths that occur on many woody plants including fruit trees, grape vines, and ornamentals. In 1907 researchers at the USDA discovered that the cause of crown galls was a soil bacterium, Agrobacterium tumefaciens. Other bacteria were known to cause plant diseases but A. tumefaciens had the unusual ability to cause the plant that was hosting it to grow a disfiguring tumor. Forty years later in 1947 researchers at the Rockefeller Institute for Medical Research (now named Rockefeller University), curious about the crown gall bacterium and using it for insight into how tumors developed, grew crown gall tissue culturally free of any associated bacterium AND free of the plant host as well. They found that these uninfected crown galls could continue to grow, as crown gall tissue, independently of the crown gall bacterium and of the plant host for many years. It was concluded that normal plant growth in some unknown way had been permanently and irretrievably transformed by A. tumefaciens. Understanding how would have to wait nearly another thirty years. During the 1950s and 1960s, scientists discovered DNA’s role in transmitting information from plant to plant and ultimately controlling plant growth. Armed with this new information, scientists began looking more closely at DNA’s role in the formation of crown gall. The crown gall mystery was attacked again when several investigators began, logically, looking for the tumor-inducing factor in the bacterium’s DNA. Bacterial DNA is relatively simple compared to other types of organisms since it can be normally found on a single chromosome. It wasn’t found there. Instead it was found by Flemish researchers on a smaller, mobile DNA unit called a plasmid that was not part of the bacterium’s single chromosome. In a series of experiments at the University of Washington ending in 1977 researchers found that this bacterial plasmid was spliced into the chromosomes of plant cells when the bacteria infected the plants. This was at the same time that researchers in other fields were just beginning to understand how to manipulate genetic information by a technique called, in lay terms, gene splicing – to cut and splice foreign DNA into the genetic code of an organism. It became clear now that A. tumefaciens transmitted the genetic information needed to cause a plant to produce tumor-like growth through the transfer of a “packet” of information called a plasmid. This plasmid altered the genetic makeup of the plant so that the infected cells of the plant were induced to divide continually, developing galls containing the genetic information from A. tumefaciens. What if scientists could manipulate A. tumefaciens so that it no longer transferred the genetic information for creating crown gall but instead transferred genetic information into plants that produced desirable traits such as resistance to insects or disease? To convert the A. tumefaciens plasmid into a beneficial plasmid (now called a vector) researchers first had to locate and then replace the tumor-inducing genes. By 1983, plant molecular biologists had developed the first plasmid vector for plants susceptible to crown gall from A. tumefaciens. The crown gall disease had changed plant breeding forever. A tool for introducing genes into plants is useful only if scientists have found genes that they want to transfer. Enter Monsanto. In the late 1960’s researchers at Monsanto wanted to know what made the nonselective herbicide glyphosate (RoundupTM) a potent killer of so many different kinds of plants; weeds and crop plants as well. It seemed reasonable that if you could alter crop plants so that they were resistant to glyphosate, then spraying an herbicide like glyphosate “over the top” of a mixture of emerging combination of resistant crops and weeds would kill the weeds but not the crop. Through combined research starting early in the 1970’s glyphosate’s genetic “mode of action’, destruction of an enzyme vital to all plants, was specifically identified by research performed at Monsanto and by German researchers. In 1983 researchers at Calgene and Monsanto identified the gene, and Monsanto modified the gene, so that the enzyme it produced was no longer sensitive to glyphosate. The A. tumefaciens plasmid vector was used

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My Beans Emerged From the Soil and Died

Leave a Comment / bush beans, crown rot, disease, string beans, stunted growth / xtremehorticulture

A good indicator of collar rot is when the plant shows less vigor than it should or less vigor than its neighbors Q. I recently planted bean seeds in pots on my porch here in Las Vegas. However, after the bean stalks were half a foot tall, they bent over, turned dark and died. A. This is probably crown rot. If you plant beans when the soil is too cold they have a huge chance of developing crown rot at the point where the bean stem enters the soil. This causes the stem rot, the plant dies or we say “collapses”. If you plant them when the soil is warmer, they have less chance of this happening. Once the plant is lifted from the soil you can inspect the stem at the soil level. Where the brown part of the stem and the green part starts was the soil level. This is also the place where the bean stem was attacked by collar rot fungi. Avoid planting in soils that are too cold.

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What to do When Your Indoor Palm Has Sticky Leaves

Leave a Comment / palms, scale insects, sticky leaves / xtremehorticulture

Q. My indoor palm plant has developed a sticky-looking, shiny appearance on the leaves. Also, small, 1/16″ brown spots/bumps on the leaves and stems. What is this? Scale on palm leaf but unfortunately the plant also has spider mites judging from the yellow speckled appearance of the leaf A. This is probably one of the scale insects. It is living under this brown bump and sucking plant juices while totally protected by this bump or shell they build on top of themselves. This brown bump is what keeps them alive when pesticides are sprayed on the plant. BUT they are susceptible to poisons or insecticides that are taken up into the juices INSIDE the plant. So, systemic insecticides, those that are applied to the soil or sometimes sprayed on the leaves and taken up through the leaves, can be quite effective on these protected insects. Since it is a palm and you are not eating anything from it you can use these types of poisons on these plants. You will have to try to find one at a nursery or garden center that carries a systemic insecticide that has a label specifically for houseplants and controlling scale insects. The shiny stuff on the leaves is sticky since this is the sugary excrement of these scale insects falling on the leaves. Frequently it attracts ants.

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Is Now a Good Time to Fertilize Shade Trees?

Leave a Comment / fall fertilization of shade trees, ornamental trees / xtremehorticulture

Apply fertilizer to the irrigated areas and just outside the irrigated areas, just below the soil surface, no deeper than this Q. There are six trees on our property; a Raywood ash which is 10 years old, Arizona ash also 10 years old, California pepper (taller than our 2 story house and 8 years old), Bradford pear also 10 years old, a young African sumac and a young palo verde. Is now (October – November) a good time of year to deep feed these trees? Also, we’ve got a three foot long tree root from the pepper that’s growing along the top of our lawn. Can I cut that part out this time of year? A. You can deep root feed these trees (put the fertilizer in the root and watered area at about half a foot, no more) now that the trees are preparing for winter and stopped growing but they should still have green leaves on the tree. If there is no grass there then apply it to the surface of the soil and water it in. Water the fertilizer in the root zone three times over the period of one week and then continue to cut back on your irrigation for these trees as you normally would for the winter. The living green leaves on the tree will help move the water laced with fertilizer into the trees and into storage for next spring’s growth. It also places fertilizer in the area of the roots for next season provided you don’t water too much. You can then skip a spring application of fertilizer. If the leaves have turned yellow or are starting to drop, you missed it for this year. Wait until next spring. There is no advantage to applying it in the fall vs. spring except possibly convenience.

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Not All Cactus Fruit Are Desirable for Eating

Leave a Comment / auto immune illnesses, bunny ears cactus, edible, food, nopal, nopalitos, Opuntia, tunas / xtremehorticulture

Bird damage to nopal fruit called tunas in Mexican Spanish. Bird damage to cactus fruits is a good indicator tunas will have good quality for human consumption. Tunas are high in vitamin C. Q. I have a large cactus garden in my front yard and much fruit. My cactus are the”bunny ears” type. Is the fruit of this type good to eat and does it have health benefits? I am a retired teacher and just read your article on cactus fruit. I have made jelly from them in the past. I suffer with Crohn’s disease and wonder if this fruit is comparable to the Nepolia (sp?) health drink that costs so much. Since Crohn’s is an auto immune illness, I wonder if this fruit has some good anti-inflammatory properties? Thank you for your time and any help you can give me. A. Sorry to hear about your health concerns. The fruit would definitely be edible BUT not all Opuntia type cacti are as desirable as others for eating. The nopal cactus is also a “bunny ears” type but the fruit may not be as edible. In some nopal cactus the sugar content may be as high as 30% which would rival fully mature wine grapes in sugar content. I normally will get about 16 to 18% which would rival a really good apple or peach. A good indicator about whether it is going to be a good one is how the birds use the fruit. If birds are devouring the fruit then it will have some really good characteristics for human consumption. If the birds leave it alone, well… it probably has low desirability. So look for bird damage to ripe fruit. Nopal or bunny ears cactus is selected for edibility so not all of these cacti are as desirable as others for food. As far as health benefits goes, I have heard that it is of course high in fiber content, helps to lower cholesterol, helps reduce high blood pressure, is normally high in Vit C (reds are the best) but I have not heard anything about auto immune system benefits unless you want to count the Vit C content as part of that. But I am no health expert and you would probably have to do some digging in the literature online for that information. There are some good papers out of the University of California with the University of Sonora on this subject in the past. Also if you want to start growing cactus for food you will have to alter your irrigations to push new succulent growth starting in about March. A deep irrigation every two weeks is all that is needed along with a fertilizer application high in nitrogen in the spring. Compost applications at the time of planting and on the surface each year will also help push new growth.

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How Far to Cut Back Ash Without Killing Them?

Leave a Comment / Fraxinus, ornamental tree, pruning, shade tree / xtremehorticulture

Example of a thinning cut made to peach. The cut is made directly above a side branch going in a preferred direction or a smaller one that will help to reduce the size of the plant. Q. We have two fantex ash trees, 15 years old. They are spreading out too far. How far can we cut them back without killing them? A. The problem with ash is that it does not have much ability to come back from cut limbs if you cut back too far. You can begin structuring the tree if you do it fairly early and stay on top of it but if you let it go too long and then cut it back you may have some problems. You can cut it back to side branches that are growing in a desirable direction but you cannot prune it back by what we call heading cuts (stubbing it back) and hoping these dead end cuts will resprout. You can cut back into about second or maybe three year old wood (there are still side buds remaining that can grow) but if you cut into a limb with no buds present it will probably die back to a major limb. So cut back to a branch at a crotch going in the direction you want it to grow. When limbs are growing the wrong direction, eliminate them back to a crotch or another limb. Do not leave any stubs (dead end cuts). The Modesto ash on the right was “topped” and because of the nature of ash it never came out of it but had to be removed. The one on the left was cut back early enough so that it could resprout from young wood. Consequently the one on the left developed swellings just under the cuts that are full of tissue that can generate new growth. The one on the right could not. I hope this makes sense. I attached a picture of a thinning cut made removing a larger limb going up…to a smaller limb going out and toward the camera. The direction of growth of the limb was changed without leaving a stub.

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