Q. My purple plum has branches that are dying on one side of the tree. The leaves are all brown and crunchy while the other side seems healthy. Please help. A. It is important to try and find out what the problem is if possible. From your description 1/3 tree has leaves that are dead or dying. These leaves are brown, dry and withered and possibly dead. Something is causing water not to reach the side of the tree that is withered and appears dead. This means there is damage to the limb or trunk below that area. Please inspect the larger limbs and trunk below it for wounding or bark that is peeling away from the trunk. If the tree is in a rock landscape, which is really not good for this tree, make sure that water is getting to that side by turning on the irrigation system and making sure water is coming out. You might try putting a hose at the base of the tree and a soaking the area around the tree slowly over a couple of hours. Do this once a week along with your normal irrigations and see if this makes a difference. But my best guess is that something has damaged the tree below the problem area. You still have time this year to help get it recovering from this damage before leaf drop. Response from reader:  Yu are correct. I just inspected the tree, which is not in a rock landscape, and found several wounds at the base of the truck near the ground. There are places on the truck where the bark is peeling away. Additionally, the branch that did not produce many leaves has a ½ inch split in it; the wood looks dry. The only reasonable explanations for this problem that I can come up with are (1) the gardener may have damaged the tree with his mower or lawn edger, or (2) borers may have damaged the tree before I treated it for insect infestation. There is no well around the tree; the grass grows around the base of the truck. I am watering my tree now and praying for its recovery. My response to reader: Good detective work! You are right, if the damage goes a considerable way around then this could be the root (pardon the pun) of your problem. Let’s determine if it is weed whacker or borer damage, shall we? Pull any loose bark away from the trunk. Look for accumulations of sawdust in channels that run parallel with the bark but just under it. A pen knife might work well to see if this sawdust “frass” located in the exposed tunnels just under the bark indicates a borer problem or not. If this is weed whacker damage (can be very likely and a common problem when grass is allowed to grow right up to the trunk) then there will be no frass or elliptically shaped exit holes about 3/8 inch long. Regardless of the outcome, remove the grass out a distance of two feet from the trunk. Can be a circle if you want but doesn’t have to be. If you want to be creative make it a square or even a trapezoid! But get the grass away from the trunk so the weed whacker doesn’t damage it.

Picture from reader most likely sunburn on the berries Q. My husband and I attended your seminar earlier this year regarding growing grapes and making wine. It was very interesting and helpful. We have been growing the Thompson “tasteless” for about four years now and they are doing quite well, however, our second year wine grapes, Cabernet and Black Spanish, appear to have black rot according to the internet pictures. Can you tell me if this year’s crop can be saved? A. We don’t have this disease west of the Mississippi to my knowledge. That is an East Coast grape disease problem. We have very few grape disease problems in our climate due to our very low humidity and geographical isolation. It is more likely to be sunburn. From the picture you sent me the discoloration is typical of sunburn and it seems to be facing the sides toward the sun. Make sure when the berries are developing that they are in the shade of the canopy as much as possible during the heat of the day. They should have as much indirect light as possible to help in color development (which also helps in the color of the juice or wine). Grape trellis with parallel catchwires on the top to “catch” the new growth and provide shade to the berries When you trellis the grapes you want to make sure that the bunches are shaded from direct light as much as possible by the overhead canopy of the vines. We use a catchwire about 18 inches above the cordon wire to do this so that the fruit remains protected but still allows for plenty of indirect light. The fruit needs sunlight to develop good color and antioxidants. They should also have plenty of air movement around bunches so that the few disease problems we have are minimized. We sometimes pull leaves off of the vine surrounding the bunches to increase indirect light and air movement. Grapes berries usually turn color (called veraison) in July through September depending on the variety being grown. Most of our wine grapes are ready for harvest in late July and into most of August. Veraison will also turn the berry a different color as it spreads through the berries but from your picture this is not what I am seeing. Our wine grapes entering into veraison at 115F (46C) daytime temps Not all the grapes will be turning color at the same time nor will bunches be ready for harvest all turn at the same time. In the extreme heat of July and August color development can be very spotty through the bunches with some much further along than others. I have attached a picture of our wine grapes entering into veraison with some berries totally dark while others are still green and yet others turning color.

Q. Do you have any idea how to get rid of snails? I have a factory! There are literally hundreds throughout my grass andplanters. They are very small and we rarely see the large ones so not sure if they are regular snails or what. But I’d like to get rid of them because they grab onto the kids shoes which can bring them in the house. Picture of the snail culprit from the reader. Out, out, dam ned snail! A. Snails are not usually a huge problem here due to our lack of moisture and sparse plant growth. However in a garden situation where there is plenty of water and debris on the ground they can get established, usually being brought in on nursery or garden materials. The basic strategy is to minimize water by using drip irrigation whenever you can and clean up ground debris to remove hiding and egg laying places. Traps can be put out which is basically used so that you have some central locations where you can find them and kill them. Usually once you get these traps established and conduct raids daily for about two weeks you will lower their numbers substantially. Then once or twice a week is all that is necessary to maintain lower numbers. There are some devices such as copper barriers and diatomaceous earth that can be used to keep them out of specific places. Then there are the chemical baits containing metaldehyde and Sevin, an insecticide. The following I copied verbatim from the University of California IPM website a couple of months ago. But check to make sure the information is current at their website located at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7427.html Snails and slugs are among the most bothersome pests in many gardens and landscapes. The brown garden snail, Cornu aspersum (formerly Helix aspersa), is the most common snail causing problems in California gardens. It was introduced from France during the 1850s for use as food. Another troublesome snail is the white garden snail, Theba pisana. It currently is established only in San Diego County but has been found in Los Angeles and Orange counties as well. Several species of slugs also cause damage including the gray garden slug (Deroceras reticulatum,formerly Agriolimax meticulatus), the banded slug (Lehmannia poirieri), the three-band garden slug (L. valentiana), the tawny slug (Limacus flavus), and the greenhouse slug (Milax gagates). IDENTIFICATION AND BIOLOGY Both snails and slugs are members of the mollusk phylum and are similar in structure and biology, except slugs lack the snail’s external, spiral shell. These mollusks move by gliding along on a muscular “foot.” This muscle constantly secretes mucus, which facilitates their movement and later dries to form the silvery “slime trail” that signals the presence of either pest. All land slugs and snails are hermaphrodites, so all have the potential to lay eggs. Adult brown garden snails lay an average of 80 spherical, pearly white eggs at a time into a hole in the soil. They can lay eggs up to 6 times a year, and it takes about 2 years for snails to mature. Slugs reach maturity after about 3 to 6 months, depending on the species, and lay clear, oval to round eggs in batches of 3 to 40 beneath leaves, in soil cracks, and in other protected areas. Snails and slugs are most active at night and on cloudy or foggy days. On sunny days they seek hiding places out of the heat and bright light. Often the only clues to their presence are their silvery trails and plant damage. In areas with mild winters, such as southern coastal locations, snails and slugs can be active throughout the year. During cold weather, snails and slugs hibernate in the topsoil. During hot, dry periods or when it is cold, snails seal themselves off with a parchmentlike membrane and often attach themselves to tree trunks, fences, or walls. DAMAGE Snails and slugs feed on a variety of living plants and on decaying plant matter. They chew irregular holes with smooth edges in leaves and flowers and can clip succulent plant parts. They also can chew fruit and young plant bark. Because they prefer succulent foliage or flowers, they primarily are pests of seedlings and herbaceous plants, but they also are serious pests of ripening fruits that are close to the ground such as strawberries, artichokes, and tomatoes. They also will feed on foliage and fruit of some trees; citrus are especially susceptible to damage. Look for the silvery mucous trails to confirm slugs or snails caused the damage and not earwigs, caterpillars, or other chewing insects. MANAGEMENT A good snail and slug management program relies on a combination of methods. The first step is to eliminate, as much as possible, all places where they can hide during the day. Boards, stones, debris, weedy areas around tree trunks, leafy branches growing close to the ground, and dense ground covers such as ivy are ideal sheltering spots. It won’t be possible to eliminate some shelters such as low ledges on fences, the undersides of wooden decks, and water meter boxes, so make a regular practice of trapping and removing snails and slugs from these areas. Locate vegetable gardens or susceptible plants as far away from snail and slug hiding places as possible. Reducing hiding places allows fewer snails and slugs to survive. The survivors congregate in the remaining shelters, where you can more easily locate and remove them. Switching from sprinkler irrigation to drip irrigation will reduce humidity and moist surfaces, making the habitat less favorable for these pests. Choose snail-proof plants, such as those listed below, for areas where snails and slugs are dense. Copper barriers can be useful for protecting especially susceptible plants. Though baits can be part of a management program, it is better to use them in conjunction with other habitat modification, especially in gardens that contain plenty of shelter, food, and moisture. Plant selection can greatly affect how difficult your battle with snails and slugs will

Pvc glue plugging an irrigation bubbler after a repair Q. A few years ago I had a bubbler system installed to water my trees for my desert landscaping. They did not do a good great job. It has gotten plugged a few times and the trees do not get enough water. I have gone through four trees and maybe another. Would you give me some names of trees that are truly drought resistant? A. I hesitate giving you suggestions on plants because that is a highly subjective decision and secondly without a reliable irrigation system nothing will work in our desert except maybe Joshua trees. Besides, in our desert there are no ornamental and shade trees that will survive or look good without a good irrigation system. Y filter for drip irrigation  Salt accumulation on a drip emitter  Make sure your irrigation system has a 150 to 200 mesh filter installed somewhere before the water reaches the emitters. This will reduce plugging. Make sure that when you or anyone repairs a drip system that they DO NOT use a pipe cutting device that rips the piping. So do not use a hacksaw or other pipe cutter that uses teeth to rip at the pipe. This will leave pipe debris in the lines that will (guaranteed) plug your emitters. PVC cutter that does not leave debris in the pipes Use only a cutting device that has an unserrated knife edge that cuts the piping. Use pipe cutters instead. They are more expensive but will actually work quite well. I don’t care how careful you think you are, don’t use devices that rip or shred on any part of a drip system. Once you have a reliable irrigation system then you can plant some good stuff.

Dog urine damage leaves a dark green edge around the damaged brown spot caused by the urine Most likely there is a popup sprinkler in the center of that green patch surrounded by bare soil. It is most likely a two inch popup when a four inch is needed in tall fescue Q. My lawn was sodded with tall fescue lawn grass a few years back and this past fall noticed I still have two problems. The pictures attached. The first are five to ten inch circles which are brown in the center with very dark green grass around it. The second are areas around the edge where there is a patch of dark green grass and then 10-15 inches of bare ground around it. I am really hoping you can provide an explanation and solution to resolve these. A. The third picture, brown ten inch circles with dark green on the outside, looks like damage from a urinating dog. Urine results in a small round brown area where the grass is darker green around the dead spot. Readers can see these pictures by following my blog at http://www.xtremehorticulture.blogspot.com/ Popup sprinklers need clearance over the grass if they are going to cover the lawn area evenly The urine is too high in salts (urea, a salt high in nitrogen) and burns the immediate area around where it is applied. As the urea moves into the surrounding soil it becomes more dilute, reducing the burning, and then acts like a fertilizer high in nitrogen. Nitrogen fertilizers turn grass a dark green. The other picture with 10 to 15 inches of bare ground around a green area, looks like the sprinkler head is in the center of that small green area next to the curb. If that is the case, I am guessing the popup is not “popping” high enough. Make sure it pops up all the way and is not getting blocked. Make sure your irrigation sprinklers are 4 inch and not 2 inch popups. Two inch popups do not pop up high enough to spray evenly above the top of a grass mowed at two inches in height. The grass height interferes with the water spray. Pressure regulator Also check your water pressure. It should be in the 40 to 50 psi range for most popups. If it is a lot higher than this, then your sprinklers are probably “fogging” and not delivering the right sized droplets to get even coverage over the lawn. Install a pressure regulator to drop the water pressure in the appropriate range recommended by the irrigation manufacturer for the sprinklers and nozzles. Your tall fescue does not look very luxurious in general. It would improve from some good lawn management practices. Tall fescue is best if mowed no shorter than 1½ inch, and 2 inches is even better. Use a mulching mower and return the clippings to the lawn; don’t bag them and leave them for the garbage. Roots of turfgrass grow easily into holes punched in the lawn by an aerifier Try aerating the lawn any time of the year and follow this with an application of a good quality lawn fertilizer. If you are returning the clippings to the lawn then fertilize Labor Day, Memorial Day and 4th of July. Be sure you also make an application around Thanksgiving to keep your lawn dark green through the winter months.

 Armenian Cucumber  Q. I live in Las Vegas and want to grow baby cucumbers for pickling. I tried to grow some last Spring but was not successful. I didn’t realize until the plants were about 1ft tall that I was supposed to thin them out. I did thin them but it may have been too late. The plants looked good and grew well but when they began to flower, the little tiny cucumbers got very dry and hard and shriveled up. The pot was getting full sun most of the afternoon so my husband built an open lattice over the top for some light shade. As the later part of June approached the plants were not looking good and I gave them up, with the intention of trying again, maybe in the fall when it’s cooler? I was so looking forward to growing and pickling my own. A. Cucumbers have a fairly narrow time for production here as it gets too hot, from about late March or early April to about June. They can suffer from chilling damage if temperatures get below about 50F. You can plant again in September since they have a fairly short production time, about 60 days. Soils should be well composted and fertilized before planting. No lack of water for these plants or you will have problems. Soils must be kept moist so cover the soil with straw mulch or other mulch you can till or spade in afterwards. You will have less waste if you trellis them rather than letting them lay on the soil. In the warm times you will pick three times a week. The easiest to grow is Armenian cucumber but will not make very good pickles. Others to try for pickles might be Eureka and Valispik. Other vegetables and even fruit make great pickles as well.