June 2014 – Page 3 – Xtremehorticulture

Homemade Recipe Weed Killer From Reader

Q. A friend gave me the following recipe for homemade weed killer. 1 Gal. Vinegar 2 C Epsom Salts ¼ C Dawn dish soap—blue original Spray on weed in the morning after the dew is gone. Be sure to wash the sprayer well after us because vinegar ruins the rubber gaskets. My husband says that the salt could leach into areas that we don’t want to kill. Also, will the above recipe kill all it comes in contact, grass and broadleaf weeds? I would appreciate your thoughts on this. A. I am not sure it will work but give it a try. The Epsom salts is a safe salt to use, not like table salt which is more like what your husband is thinking about. Table salt is sodium chloride. Both the sodium and the chloride are toxic to plants and the sodium in particular can cause longer term problems with the soil. Epsom salts is calcium and magnesium carbonate salts. Safe for plants and used on roses by lots of Rosarians. My experience with vinegar as weed killer is that the acetic acid has to be above 15% which is hard to find.

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Who Stole All My Almonds?

4 Comments / almonds disappeared, almonds eaten, bitten, green almonds bites / xtremehorticulture

Q. Our almond tree was full this year. However, half of our crop was eaten by something. The nuts are not ready yet. They are still green and so hard you would need a nutcracker to crack the shells open. My husband picked the rest of the almonds so we at least had something to enjoy. Any ideas as to what’s eating the nut and cracking them open? A. This is most likely ground squirrel harvesting. Technically I think they are called antelope ground squirrels and they are very common in southern Nevada. We find them typically at residences near or bordering the desert or large expanses of desert landscaping or open lots. In almond orchards ground squirrels can harvest an almond tree overnight. They are very active right now, chewing open the green, hard husk and taking the immature seed. Seeds right now are soft and sweet, not yet hardened. You will see lots of empty shells on the ground from these critters. Empty almond husks at the bottom of the tree’s canopy from ground squirrels Ground squirrels continue to feed on nuts throughout the season. When the husk splits open, they steal the nuts a lot faster and store them away somewhere. It is usually safer to harvest the nuts as soon as they split open and not leave them on the tree to dry. Ground squirrel grape thievery I know that these little guys look cute but they can be real pests if they get out of control. They will also steal grapes right out of bunches. Bunches with stolen grapes look just like you think they might look, a bunch with grapes missing here and there on the outside of the bunch. Antelope ground squirrel adding insult to injury Control is not easy nor is it any fun. In commercial orchards they frequently use poison bait to help control the population. There are other options such as trapping and relocation. Please be very careful when dealing with ground squirrels. It is rare but they can transmit the Plague from flea bites or bitten directly by the ground squirrel. Here is some very good information on ground squirrels from the University of California Ground squirrels

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Nectarine Fruit and Dried Droplets of Sap

5 Comments / disease, flower thrips, insect damage, nectarine fruit damage, scarring / xtremehorticulture

Q. I have an Independence nectarine tree which I have been nurturing for two years. This is the first year I have had fruit! On the fruits I kept I am seeing something that looks like dried droplets of sap coming out of the skin. It is not sticky to the touch. Are you able to determine if I have some sort of blight with the fruit? Will I just need to take this plant out? A. Your nectarine fruit has damage caused by Western Flower Thrips. This is a very common problem with nectarine fruit here in the valley and elsewhere. Once you see your fruit damaged by this insect, you will see it in future years as well. Be prepared to spray. Damage to the fruit starts before they are the size of a pea. The only control is to apply sprays to the fruit and leaves to protect the fruit from thrips damage. The most effective sprays are insecticides for organic production contain Spinosad in the list of ingredients. Follow the label precisely. Readers nectarine fruit with dried sap due to thrips damage If you don’t mind applying an effective conventional insecticide, then look for one containing synthetic pyrethrins, sometimes called pyrethroids. The label must say it is approved for tree fruits. Again, it is very important to read and follow the label for best results. These sprays must be applied to the fruit and leaves starting very early in the season when the fruit are still very, very small. Sprays must be repeated through the season for total protection. Chances are, you will still see some scarring of the fruit but it will be greatly improved.

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Tops Dying Back in Japanese Blueberry

3 Comments / borers, dead branches, disease, insect, Japanese blueberries, sunburn, top dead / xtremehorticulture

Q. I’m having a problem with my Japanese blueberry trees. Some are fine but the two on the end appear to be drying out from the top down. Do you have any idea what’s causing this? The soil is not dry and they all get the same amount of irrigation. A. The usual problem in damage or death to the top of a tree can be found on the main trunk just below the damaged area. I am guessing something has damaged the tree at that point. The reason for the damage could be several. Borers cause mechanical damage to the trunk and shut off the water going to the top. Diseases in this same location can do exactly the same thing. Because Japanese blueberry is relatively thin barked, sunburn from our intense sunlight can kill the trunk in that location and shut off water to the top. Humans can cause damage to the trunk and shut off its water supply as well. Top of dead stem on readers Japanese blueberry I think we can rule out pathological diseases in our climate. The two most likely culprits are mechanical damage to the trunk by borers or the same type of damage caused by sunburn. Inspect the trunk at the location just above the healthy area of the canopy. Use your fingers and see if you can pull away any loose bark. Borers tunnel just under the bark usually on the side towards the most sunlight. This kills that part of the trunk and the bark peels away easily. If you don’t see bark peeling from the trunk at this location, look for discoloration of the trunk on this side facing the sun. Sunburn to the trunk can happen in one hour of intense sunlight during the midday or late afternoon. If it is borers there is nothing you can do to raise the dead area back to life but you can protect the tree from extensive borer damage with an insecticide soil drench once a year. In any case, you’ll be forced to remove the dead top from the tree with a pruning shears or saw this winter. Once you do this, it may open remaining branches for sunburn as well. Give them as much protection as you can. I would not do it now because the sunlight is too intense and will probably cause even more damage to the lower, healthier part of the tree.

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Pepper Brown Spots Could Be Irrigation or Sun

Leave a Comment / bell pepper brown spot, blossom end rot, blossomend rot, dead spot, sun burn, sunburn / xtremehorticulture

Q. I have a brown area on the bottom of my bell peppers. Any ideas? A. Brown spots on bell peppers are normally from either of two things; a disorder we frequently see on tomatoes called blossom end rot or sunburn. If it is on the bottom of the fruit and not in a spot exposed to direct sunlight it is most likely blossom end rot of pepper. Blossom end rot, just like in tomatoes, is normally associated with irregular watering even though it is a nutrient deficiency. An inch of mulch in the vegetable bed helps to maintain more even soil moisture and less fluctuating of the water content in the plant. A more even soil moisture content has been reported to reduce the incidence of blossom end rot. Blossom end rot bell pepper The other possibility is sunburn. If the brown spot is on the shoulder of the fruit toward the sun and not the blossom end, then it is most likely sunburn. This is because there is not enough shade covering the fruit. You will see less sunburn on peppers that are buried deeper inside the canopy of the plant. With bell peppers in particular we want as much leaf cover over the fruit as possible. Light shade, about 30%, over the plants, also reduces sunburn. Mulching the vegetable garden also helps. Having the garden in a location where it is exposed to morning and early afternoon sun, with shade during the late afternoon, will also reduce the problem.

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Importance of Surface Mulch for Vegetables

3 Comments / how much to use, mulching vegetables, what to use, when to apply mulches to vegetables / xtremehorticulture

Surface mulches are under appreciated when growing shallow rooted vegetables during the heat in hot, desert or arid climates. Learn why. Using mulches when growing vegetables can be very important in hot, dry climates. Garden soils dry quickly and a surface layer of mulch helps keep the soil cooler and retains soil moisture much better than a loose, uncovered garden soil. This can be particularly beneficial to shallow rooted vegetables such as onion, garlic and other root crops. Try to use light colored mulches like this bedding in the summer months to help reflect energy from the sun and keep it from heating up the soil. In the winter time when the air temperatures are much cooler, use dark colored mulches to help warm the soil and speed germination. Mulches help keep the soil cooler, retain moisture and suppress weed seed germination. Organic mulches which decompose help add structure to desert soils. The problem has been what to use and cost. In the past I have used clean, bailed straw but it is expensive and doesn’t decompose rapidly when it is fresh. You can turn it under after harvest and it will decompose but it decomposes rather slowly. I tried using wood shavings like you can use for horse bedding. It works well as you can see from this picture of onions that were mulched versus onions that were not mulched in front of them. The horse bedding can be turned under easily after harvest and decomposes rapidly in moist soils. I was pretty impressed with it and it’s cheap. I got the horse bedding in 3 1/2 cubic foot bags from Viragrow in Las Vegas for $4. I am sure you can find it other places as well. I put down about half an inch of horse bedding on top of the soil in April before the heat and it made a big difference. If you are going to seed in the heat, I would highly recommend mulching the surface with something like this. You can also take the time to shred newspaper and it will do about the same thing. A big problem starting plants from seed in the garden during the heat is the soil drying too quickly and the see failing to germinate or germinating very slowly.

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Lack of Flowers in Petunia May Be Tobacco Bud Worm

Leave a Comment / gardenias, nicotiana no flowers, petunia no flowers, stopped flowering / xtremehorticulture

Q. My husband planted some gorgeous petunias in early April. At first they were all blooming but now there isn’t a single flower in either of the planters. We noticed many holes in the leaves so my husband sprayed them with Sevin thinking that would do the trick. All we have is two planters filled with very healthy green plants but no flowers. A. This is most likely tobacco budworm. The adult is a moth but the damage is done by the larval or caterpillar stage. In this stage the caterpillar feeds on flower buds and leaves. The giveaways that it is tobacco budworm are the lack of flowers, holes in the leaves from feeding, the type of plant and the time of year. The flowers fail to open so lack of flowering is a pretty good indicator the pest is present. Small holes in the leaves are another good indicator. Besides petunia, tobacco budworm likes geraniums and nicotiana. Once in a while we might see damage on roses. In the future, if you have these plants, look for holes in the leaves starting in April or May. That would be a pretty good time to start thinking about getting control because its population builds through the summer if not stopped. Check your plants for these caterpillars as the sun is setting. This is the easiest time to find them and pick them off of the plants with your fingers. During the daytime they like to hide out close to the soil. Tobacco budworm has become fairly resistant to a lot of insecticides so control is a little bit difficult. This is why you probably did not get controlled using the insecticide Sevin. Be really careful with that insecticide because it is pretty hard on bees. You might try an insecticide with Spinosad on the label. Dipel or Thuricide might give you some control. Otherwise use insecticides that contain synthetic pyrethroids in the list of ingredients. Regardless of the insecticide used, always spray either very early in the morning or at dusk when bees are no longer present.

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Caterpillar Webbing on Texas Mountain Laurel Now

Leave a Comment / caterpillars, leaves eaten, webbing, worms on mountain laurel / xtremehorticulture

Now is the time you may be seeing some webbing in your Texas mountain laurel tree or shrub. This happens nearly every year but is relatively easy to control. There is a moth, called the Genista moth, that lays its eggs on the stems of Mountain Laurel. When these eggs hatch into small caterpillars or larva of the moth, they feed on the leaves of this plant. Prior to doing that, they form some webbing around their kitchen area. Texas mountain laurel They normally do not cause a lot of damage but in some cases their numbers can be so high that the visual damage can be alarming. This is a little strange because the leaves of Texas mountain laurel are considered to be somewhat toxic. Most animals do not want to eat those leaves. But this caterpillar has evolved with this plant and can tolerate these toxins. These toxins reside in the caterpillar and sold the caterpillar in itself is not a favored food of predators. Plus the silken webbing deters other potential enemies. If you have these plants in your landscape, you might check them for damage. If the damage is minor, just leave them alone. If it is severe, organic sprays of Dipel or Thuricide will normally control. You may have to destroy the webbing so that the spray can land on the leaves they are eating. This organic spray relies on the caterpillars eating sprayed foliage. The webbing may interfere with the spray landing on the leaves. You can also use Spinosad and it will do about the same thing. Several sprays of insecticidal soap will also probably work.

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