Xtremehorticulture

Oleander Freeze Damage Can Be Fixed By Cutting Plant Back

Q. I have an oleander that suffered extensive freeze damage this past winter. It is still brown but coming back slowly. I would like to improve the looks of the bush without killing it. Should I prune the dead looking branches or just let it go Freezing damage to oleander. A. Prune the oleander back to about an inch or two of the soil surface. After this, apply fertilizer and water it deeply several times a week apart.             If it has been established for at least a couple of years it will grow back with a lot of vigor. Oleanders are very drought tolerant but to look nice they require quite a bit of water. This oleander in rock mulch was cut back to about six inches of the rock surface. It can be cut back further than that and it will sucker back up to its origninal height quickly due to its established root sytem.

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Stinkbugs Attack Residence and Car in Henderson Nevada

Q. We have thousands of these beetles in our trees here in Henderson. Yesterday they collected on a neighbor’s car by the thousands.  They sprayed them off. These bugs left imprints on the finish of their car that were unremovable. What are these bugs and what do we tell our pest control companies to do? Here stinkbugs become big nuisance for residents of Henderson, Nevada. Most stinkbugs cause plant damage. A few are actually beneficial. A. These are a type of stinkbug. I am not an expert on stinkbugs but it is one of several types that can be found here. Most stinkbugs cause damage to plants or become a nuisance as yours have done. Two more different types of stinkbugs reported by residents in Las Vegas. One for sure, the one above, was causing damage to a apricot leaves very early in the season.             Stinkbugs come in green and brown colors and in many different forms. Familiar relatives to stinkbugs are the squash bug and leaffooted plant bug, both very bad pests in squash and melons as well as pomegranates, pistachios and almonds. Squash bugs on the underside of a squash or melon leaf. They are a type of “stinkbug”.             There are a few stinkbugs that are good guys but not very many. In your case I think these are a nuisance but check your garden and landscape and see if they are feeding on important plants around your home. Leaffooted plant bug on pomegranate, another type of “stinkbug”.             Soap and water sprays applied directly to them at dusk is a good control measure which is relatively nontoxic to other insects as long as it is directed at the stinkbugs. You can buy Safers insecticidal soap at any nursery or garden center and it will be safe for plants listed on the label. Commercial insecticidal soaps are safer to use on plants than making your own from dishwashing liquid.             There are more toxic insecticides you can use as long as you don’t spray your fruits or vegetables with them. Be sure to read the labels of pesticides before buying and applying.

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Ocotillo Watering Should be Infrequent in Desert Landscapes

Q. I have trouble with my Ocotillo.  They get beautiful green leaves that last about two to three weeks and then turn brown and fall off.  They are on my watering system.  Are they getting too much water? It is common for ocotillo to lose its leaves in the winter months like this one. But it should put on some new growth and new leaves in the spring. A. Ocotillo is a desert plant so it has special characteristics that allow it to survive when water is not available.             The first response ocotillo displays to a lack of water is to drop its leaves. Another reason it may drop its leaves is from the soil around its roots staying too wet. That makes diagnosis of leaf drop difficult. Ocotillo does not require alot of care in Las Vegas like Cathy and Bill’s ocotillo. Water and fertilize infrequently.             If ocotillo is put on a “normal” irrigation schedule used for most home landscape plants, it would most likely receive water too often. It would, ideally, be irrigated with agave and yucca in a landscape, not photinia and star jasmine for instance.             It can tolerate frequent watering ONLY if water drains from the soil quickly. If water in the soil drains easily then it might be able to handle the same irrigation frequency as photinia and star jasmine even though it would not be ideal for it.             It can probably handle an irrigation frequency of about once every two to three weeks in the summer but not more often than once a week.             In winter changed it to once every 4 to 6 weeks. When it with enough water to wet the soil at its base to a depth of about 18 inches. Three or four emitters spaced about 18 inches from an established plant would be adequate in most soils.             If you choose to water with a hose, filling a basin around the plant would make it easier to water. Watch for leaf discoloration or leaf drop to signal a time to rewater. Eventually this will help you anticipate a watering schedule for the plant.

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Lantana and Yellow Bells Should Not Be Dead from Winter Cold

Q. I have had Tecoma stans, Yellow bells, in the backyard as well as lantana for the past 3 or 4 summers. They do well but never winter over. When I dig them up to replant, the root structures seem to be healthy and alive. The tag on the plant says they are cold hardy. Is there anything I can do to help them winter over?  What is Yellow Bells? Picture of Yellow Bells from Arizona State University website What is lantana?  A. Are you thinking they are dead because the tops die back? It is seldom that I see these plants totally die out in the winter here. They do frequently die back to within a few inches of the soil surface during the winter.             They then can be cut back to about one inch from the ground in February and they come back like gangbusters in early spring with some water and fertilizer. Lantana cut back in the winter to about two inches in a rock mulch in Las Vegas.             If they are dead, I am wondering if they are not getting enough water during the winter months to keep the roots from dying out. Normally a watering schedule of about every ten days or so would be enough during the winter to keep them alive.             Otherwise try mulching over the tops of the plants with a few inches of wood mulch to keep the winter cold from damaging the roots. It is very rare these would die out in the winter here under normal landscape situations.

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Treat Now to Prevent Wormy Peaches

Peach twig borer seen now flying in the Las Vegas valley. These small brown moths are very similar to the insects that produce wormy apples. Treat now and prevent that from happening later. This insect usually enters the fruit at the stem end or along the suture of the fruit. It feeds just under the skin. Usually you will see some “frass” or brown excrement at the entry point. In Nevada our experience has been that we don’t usually start catching this insect in our monitoring traps until around May. If you have had wormy fruit in the past, later in the season, it would be important to apply either Bt (Dipel® or Thuricide®) or spinosad) now to the entire tree or trees, paying particular attention to covering the fruit with the spray.  I add a surfactant (an additive that helps cover the fruit better) to the spray when mixing it in the sprayer. These organic pesticides will set up a protective barrier to this insect and keep it from getting inside the fruit. Follow label directions. Repeat applications as the label directs. A good website on peach twig borer can be found here: http://axp.ipm.ucdavis.edu/PMG/r602300611.html

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Fireblight Seen in the Las Vegas Valley in Late March

Fireblight has been seen on Asian pear, European pear and apple in the Las Vegas valley. This may be leftover from infections last year. Please remove by pruning or cutting out infected shoots, branches or limbs. This should be done with sterilized pruning equipment. Sanitize equipment between each cut with alcohol, bleach or heat. If using bleach you must oil any metal parts afterwards. Cut at least 12 inches below lowest part of infected plant part. Sanitize your tools and hands between each time you cut. Remove infected plant parts and put immediately into plastic and do not compost it. Infected tissue is black and new growth often dies in hooked growth pattern as can be seen in front of my finger.

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Uneven Garlic Growth Probably Not Due to Cold Winter

Q. Does a colder, harsher longer than usual winter affect the growing of garlic? I’ve noticed many of my plants are under-developed, or didn’t develop at all, while others have gigantic stalks! The underdeveloped ones could have been bad seed from last year’s harvest.  And other plants look like they are ready to harvest!  I have yet to dig down to inspect the bulb, and they are the first and earliest of my garlic to harvest. Size discrepancy in garlic can be due to size differences in the cloves used for planting, planting too close together and not rotating your crops. Use only the largest cloves for planting and consume the smaller ones. Make sure cloves are far enough apart to reduce competition. Do not continue to plant and replant garlic and onions in the same beds. A. In my opinion cold weather would not cause any reduction in growth or performance from a garlic clove unless the clove was damaged in some way. The only way to check that is to dig out some poor performing plants and look for a potential problem.               Was the clove too small to begin with? Was there a disease problem on the clove or plant that would cause the plant to perform poorly? Was there an insect problem causing damage to the clove or plant?               The size of the clove is related to plant size and how big your garlic bulb will grow. So if you are seeing differences in growth it would most likely be either a disease, insect or production problem. Bulb mites, onion maggot, nematodes, and some diseases. This can be true particularly if you save seed from year to year and are not careful in planting only the best cloves and make sure they are fully healed (callus over or treat with a fungicide) before planting. Get adequate room between vegetables so they don’t crowd each other. This is particularly true of root crops like onions, garlic, carrots, radishes, turnips, rutabagas, etc. Make sure you are rotating your vegetables so plants of the same families are not planted in the same spots year after year. It may sound dumb or unnecessary to inexperienced growers but this is vegetable production 101 and a common reason for losses in production in developing countries. Vegetables in the same plant families should not be repeatedly planted in the same spots year after year. You can or will develop disease and insect problems in those areas that will reduce plant growth and yield. This can lead to a buildup of disease or problems in those beds. Vegetables should be rotated from spot to spot in succeeding years to reduce the disease and insect potential in those spots. So for instance a bed used to grow garlic should not have anything planted in it from the allium family (onions, leeks, garlic, etc.) for at least three years. You can grow anything you want in those spots (tomatoes, melons, etc.) but not from the onion family. The year following that grow vegetables from the cucurbit (melon, cucumber, squash) family. The third year grow corn in that spot for instance. The next year you can go back to allium. Diseases like white rot can be a very severe problem that may do exactly what you are talking about and prevent good growth of garlic for decades in those spots once the disease is a problem there. White Rot Disease of Garlic Only use “certified” garlic cloves for seed. The plants used to produce disease and insect-free cloves are certified by an agency or company to be disease-free and you usually eliminate the risk of contaminating your beds. If you do choose to plant your own seed from garlic bulbs, each clove need to be inspected carefully for disease problems before you decide to plant it. Any blemish on the clove that could be disease-related disqualifies the clove for planting but it can be used for cooking since these diseases will never hurt an animal or human. So I don’t think cold caused the problem. I think it is related to a problem that developed during their growth.

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Small Yellow Immature Plums Dropping Sign of No Pollination

Q. I have two Santa Rosa plum trees planted in my backyard.  The one in the lawn area has about 25% small yellow plums that fall off when I flick them or shake the branches. One is planted in a lawn area and the other in a rock landscape with a mulched area approximately 6ft. in diameter.  Both are doing well with numerous large plums growing.  The one in the lawn area has about 25% small yellow plums that fall off when I flick them or shake the branches.  The remainder of the larger plums look great. Is this tree getting too much water or is this a natural thinning process going on? A. The yellowing fruit is a sign of a lack of pollination and they fall off naturally. Usually called “June drop” in some texts. I have some good pictures I can include later of plum with poor pollination. Check back after May 1st.

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Expect Those Ugly Bugs on Pomegranate and Pistachios Now!

Q. We have a big pomegranate tree that has been doing great for a few years.  Last year we had an infestation of nasty, prehistoric looking large grey bugs on our pomegranate tree. What can I do to get rid of them? These bugs had really big thighs, and smaller red ones that look like a cross between a carpenter ant and a mosquito.  This year I noticed the eggs on many branches and cut them off.  I am sure that I missed many and am wondering what I can do to get rid of them.  We  have been keeping it organic up until this point and would love to continue that since we eat as much of the fruit as possible.  Any advice you have would be greatly appreciated.  Thanks so much!!  Leaffooted plant bug on pomegrante with all the younger generations (nymphs). A. You do not need to cut those branches off. You can just rub them off with a cloth and alcohol or pull leaves off if they are the undersides. This insect is called the leaffooted plant bug, a close relative to stinkbugs, squash bug and several others that are pests in home landscapes and gardens. They get their name from the leaf-like appendage on their rear legs. Picture of adult from Auburn University. They spend the winter hiding out in landscape trees until Spring. In the Spring these bugs multiply very rapidly and feed on new soft, succulent growth from leaves and expanding fruit and nuts. This insect seems to prefer fruit trees such as pomegranate, almonds and pistachios but can be found on other plants as well. They are winged so the adults can fly from plant to plant, tree to tree or landscape to landscape. Their damage to plants includes leaf damage, leaf drop, fruit damage, fruit drop and nut drop in almond and pistachio. Control of these insects is difficult and will require quite a bit of work on your part. Organic sprays would include soap sprays such as Safers, oils such as Neem and pyrethrin sprays. Organic sprays are usually not as potent as conventional commercial insecticides so must be used more often and requires closer monitoring of the plants for buildups in their populations. Spraying multiple times through the growing season will be required because of their abilities to build their populations so quickly and their ability for flight. http://xtremehorticulture.blogspot.com/2013/06/pomegranate-fruit-failure-may-be-due-to.html http://xtremehorticulture.blogspot.com/2012/03/almond-nut-drop-and-when-to-spray.html

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Onions Producing Flowers Too Soon

Q. Hello Bob. My son got me onions that were little 3″ sprigs with roots, no bulbs, tied togather in a “bunch”, no soil. we separated them and planted a few months ago. They have grown about 7 inches or more tall and I just noticed today some of them are getting seed bulbs on their tops. But if they are large onions, why are they going to seed already? I checked the bulbs under the soil and they are maybe 2 inches around. Is that as big as they will get now that they are going to seed or should I cut the top seed bulb off? I don’t know what kind they are but do know they are not shallots or leeks. And since the bulb is so large, pretty sure they aren’t just green onions. But if they are large onions, why are they going to seed already? Please help. These are the onion flowers. Producing the flower uses enough energy from the plant. Making seed from this flower consumes even more energy. Unless you have some use for the flowers, remove them as soon as they start to develop. Twist or cut them off. A. Yes, that is the flower being produced. This can sometimes happen if there are some wildly fluctuating air temperatures or erratic irrigations. Pull or cut the flowers off unless you want to use the open flower for culinary purposes then let them open and remove them. Do not let them go to seed. Continue to fertilize the onions once a month. The safest to use is just dissolve some fertilizer that can be used for foliar applications into some warm water, dissolve it and pour it around the plants evenly. Otherwise you would do what we call “side dress” a dry fertilizer in a narrow band about two to four inches from the plants in a line parallel to the row. Do not get dry fertilizer too close to the plants or you can damage them. Do not harvest until the tops of the plants fall over. That is your clue to go ahead and harvest them over the following week or so. They will also benefit from a surface layer of mulch. This can be shredded newspaper (black and white only) around the plants.

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