Q. I have two similar African Sumac trees. One faces north the other south.  Both are about the same age, watered and fertilized the same. The south tree almost continually puts out ground shoots while the north tree seldom does. Any ideas why? African sumac is a cute little tree when it’s small and placed close to a home. It should never be this close. Place it no closer than eight feet to the home. This tree has too many stems. Remove all of them except for three or five, never four. Odd numbers are more pleasing to the eye then even numbers. A. Put African sumac trees in the same category as mulberry and many of our ash trees regarding their sexuality. African sumac has separate male flowers and female flowers and they grow on separate trees. This means that some trees are male, and some trees are female. The female trees are the problem. African sumac flowers emerge during the winter months because the tree originates in the southern hemisphere. Flowers can be male or female. Trees can be male or female. Male trees do cause some allergy problems. Female trees drop their seeds on the ground and can be invasive.             Female trees produce seed. Seed drops to the ground and germinates easily everywhere. They also produce suckers so they can sucker from the soil as well as spread their seeds. Birds like to eat these seeds so they help in dispersing them. African sumac that is 8 to 10 years old. It has a good shape for shade but it does have some problems. A number of people who have planted them in the past have regretted it. Be careful and learn about this tree before buying it.             African sumac is regarded as invasive in several states. In the desert, it can be invasive along natural waterways because the seed germinates easily. Nice-looking tree but I don’t care for it for these reasons. Would of African sumac is not terribly hard and can split under a snow load when the leaves are present. They can also be quite messy.

Q. I have cacti that attract the red insect that covers it with the white cotton like substance. Would it help if I cleaned them off and then sprayed the cactus with Volck oil? A. This is a red cochineal scale insect causing this white, cotton -like substance. They live under this cottony mass, sucking plant juices from the cactus and protected by their cottony house. If you push on this cottony mass with your finger, the insect leaves a red dye on your fingertip.             I used to spray cactus with a sweep nozzle on the end of a hose to knock off the white cottony stuff. It works but during the warm summers they are back infesting the cactus with their white cottony stuff in about one week. The secret to long-term control is knocking off the cottony stuff and then immediately spraying the cactus with a pesticide.             Oils like Volck Supreme by Ortho or Neem oil works for a while after you knock off the cotton mass. But they will be back.             I have not verified this but I heard that Volck Supreme oil has been discontinued by Ortho, the manufacturer. But that rumor has been floating around since 2014. Monterey and Bonide make good oils as well. All of them are insecticidal oils and kill insects by “smothering” them.             If you apply oils during the summer, apply in the early morning when temperatures are cool. The label warns not to use it when temperatures are too high. Spraying oils during hot summer months can result in plant damage. Never spray plants with flowers that are open because of honeybees.                 This insect will return so repeat sprays will required as these cottony masses begin to build again. There are other insecticides available giving better control but they have their downside so I hesitate to mention them. Try the oils first. Also try soap and water sprays.

Q. People in this house before us had grass in the front and in the back. Before selling the property, they put plastic sheeting over the grass and rocks on top of that. The plastic, I think, is just keeping everything moist underneath it and the grass and weeds just keep on coming up. Weeds growing in a desert landscape.. Developing a good landscape design that minimizes the wet areas in a landscape will help to control weeds. A. Putting plastic under rock mulch is never a good idea. Think of it this way: plastic is temporary. Rock is permanent. Never put something temporary under something permanent.             Putting temporary plastic mulch under permanent rock mulch always results in plastic emerging through the rocks at some time. This is unsightly, weeds emerge through holes in the plastic and the plastic eventually emerges through the rock. This requires the owner to pull the plastic out from under the rocks to keep it from becoming unsightly. This is a black plastic that was put under the rock in a rock landscape. Sooner or later the black plastic develops holes and begins to tear or rip. When this happens it begins to emerge from the rock and becomes very unsightly.             A more effective and permanent mulch under the rock is made from landscape fabrics. These fabrics are either woven or spun with tiny holes in them for air and water and have a long durability. They last a lot longer than plastic. Nutgrass which is sometimes called nutsedge, a very tough weed to destroy when it gets in your landscape.             They are expensive compared with plastic. And landscape fabrics do not prevent Bermudagrass or nutgrass from coming through it, a couple of very tough weeds to control.             Instead, put down a thicker layer of rock, 3 to 4 inches deep and no smaller than ½ inch minus. Over time, dirt accumulates in rock mulch and weeds grow in it but at least they will be easier to pull or kill. One of the better hoes I have used in rock mulch is the Hula hoe, sometimes called a stirrup hoe or simply  scuffle hoe.             The secret to good weed control is killing weeds as soon as you see them. During the first year, this requires weekly visits to your landscape and removing them with a hoe, pulling, using a fire weeder or chemicals. If pulling them, water the area first and pull them 30 minutes later. They are much easier to pull.             The first time controlling weeds, knock them all down by hand, fire or with chemicals and remove any weeds with flowers or seedpods from the property. In one to two weeks, weeds will come back with a vengeance. Control these infested areas as soon you see them. The third week, other areas will emerge with weeds. Control them immediately as well. Do this persistently and weekly for the next 2 to 3 months, pulling or killing them as soon as they appear. More black plastic emerging from underneath rock applied to the surface as a mulch. Never put a temporary mulch like plastic under a permanent mulch such as rock.             In the second year, most of the weeds will be controlled. Just control the “hotspots”. By the third season, hotspots will appear occasionally and then control is needed only as weeds become problems. Yes, this sounds like a lot of work but most will be under control in 2 to 3 months and the work becomes easier.             The mistake people make is diligence, staying on top of it. Once weeds become established, you lose the “war against weeds”.

Q. This year has been the worst for weeds and grass coming up through the rocks. I’ve tried Bayer Advanced, All-in-one concentrate which acted like a fertilizer and strengthened their growth! I got Roundup weed and grass killer concentrate. Two weeks later and the grass is coming up like I planted it. What do you suggest I use to spray on this grass to kill it?  Roundup is a proprietary name developed by Monsanto for the weed killer which contained the active ingredient Glyphosate. It was developed and did its best job killing grasses. A. Roundup weedkiller is an excellent grass killer if applied properly. Please remember this weedkiller will not kill plants in less than a week. It needs at least seven days to take effect in warm weather and more days during cooler or cold-weather. You might see some yellowing or change to the leaves in fewer days than this. It depends on the plant. There are other products now which contain the active ingredient Glyphosate and are essentially the same thing as Roundup but at a considerably lower price.             Use the concentrated product rather than ready to use if you never used it before. The ready to use form is excellent if you used Roundup in the past, you know which weeds you are killing and how they will react to this weedkiller.             When mixing this product read the directions carefully. The directions tell you how many ounces of water should be mixed with the concentrated product. If you never used this product before, use the highest number of ounces mixed in a gallon of water allowed on the label.             Water the weeds with a hose to wash off any dirt. Dirt on the leaves can interfere with how well it works.             Mow tall weeds or have them cut with a line trimmer before applying Roundup spray. The Roundup spray mixture must contact green leaves for it to be effective. Roundup does not enter through roots but through leaves so only use enough water to get the leaves wet.             Don’t sprinkle irrigate for at least 12 hours after they are sprayed. Keep kids and pets out of the area for 48 hours. If you are not confident with this application, then hire someone or have a friend or neighbor apply it for you. Note: there is a lot of controversy surrounding the weed killer called Roundup and its manufacturer Monsanto. It is not my job to tell you what chemicals you should be using ethically. Weed killers were developed so that manpower or labor could be reduced by professionals. However, I do believe it is best to use human labor to remove weeds whenever possible.

NOP Posts Fraudulent Organic Certificates  The USDA Agricultural Marketing Service (AMS) National Organic Program (NOP) is alerting the organic trade about the presence of fraudulent organic certificates. Fraudulent organic certificates listing the following businesses are in use and have been reported to the NOP: Chia-Brand LLC Mult Blindagem LTDA  (Certificate No. 53540-12) Worldwide Wholesale Warehouse, Inc. (Certificate No. 51368-13) Supattra Import & Export Co., LTD Multi Purpose Trade Marketing PTY LTD Desert Harvest, Inc. Yunnan Dianhong Group Co. Ltd. Review these and other fraudulent certificates online at: Fraudulent Organic Certificates. These certificates falsely represent agricultural products as certified organic under the USDA organic regulations, violating the Organic Foods Production Act of 1990. Fraudulent certificates may have been created and used without the knowledge of the operator or the certifying agent named in the certificate.  For more information on this subject Visit here

Q. First year with my apricot and I spray with soapy water to control aphids. Every day I check leaves but they never stop. Is this good to spray to use? Adult aphid. These are about the size of a large grain of salt. There are about 200 different aphid types and most of them only prefer a specific plant. A few of them are general feeders but most are very specific to what they like to eat. A. Soap sprays are good to make an immediate kill of an insect and don’t expect them to reestablish themselves after you’re finished. The problem with aphids this time of year is that they will come back, usually in just a few days, after soap sprays have been applied. Aphid feeding on plum leaves can cause the leaves to curl over time, thus protecting them from sprays. I am not a big fan of soap and water sprays for insect control but if you decide to make your own please use a Castile type soap free of any scents or lotions. Use a decent soap The good thing about soap sprays is that they are very safe for humans, pets and other large animals. The bad thing about soap sprays is they do not discriminate between good bugs and bad bugs. If it’s a bug and you spray it, it will die, good or bad. Soap and water is a killer             The second negative about soap sprays is they have no residual. That means that soap sprays leave nothing behind to kill bugs after the spraying is done. They have no residual. You are the residual. Soap sprays rely on you, the applicator, re-spraying when needed.             You must be knowledgeable enough to spray the bad bugs but not the good bugs. It also requires that you find most, or all of the bad bugs when you spray. If you don’t, they reestablish in a few days and you must spray them again, and continue to spray them as long as you need to, over and over, until the problem is gone. More about aphids             Aphids began infesting new growth, making more babies, as soon as the leaves popped out. Females that survived and made it through the winter on landscape plants had wings. They flew to the soft, succulent, sugary new growth and started laying eggs as soon as it came out and as fast as they could. What a good mother! Ladybird beetle with aphid             Mature female aphids that make it through the winter have wings. They can fly short distances to the new growth. These mother aphids never need a male aphid to produce their young and they produce young very rapidly. Aphids on developing pomegranate fruit. The fruit tissue is pretty hard for them to feed through but they will certainly like the much softer leaves and flower petals             It just so happens that many ants like the sugary residue that aphids leave behind when they are feeding. Those ants which use sugar for raising their young absolutely love aphids and move them to different locations on plants so that they can “farm” them. Controlling ants colonies also helps to control aphid populations. Chemical controls             Moving up the line of toxicity to aphids and comparing it to the toxicity toward humans and the environment, next try some of the oils such as neem oil, rosemary oil, mint etc. next moved to the so-called “organic” or “natural” sprays like pyrethrins.             Pyrethrins are made from a type of chrysanthemum. If you feel safe with pyrethrins, you may choose to move to the synthetic pyrethrins which are everywhere in garden stores but are not considered “natural” or organic. They leave behind a residual and continue to kill insects after they have been sprayed.

Q. So how do we eradicate poa Anna? Annual bluegrass in a hybrid bermudagrass home lawn. Notice the discoloration by the Poa when the bermudagrass is actively growing. A. Poa annua or annual bluegrass is easy to control in landscapes but extremely difficult to control in most lawns. If this is in a lawn such as a cool season grass like tall fescue, Kentucky bluegrass or perennial ryegrass it is very difficult to control. This is the worst situation. If it is growing in 100% Bermuda grass it is much easier to control. If it is growing in a landscape, around trees and shrubs, it is easy to control with mulch.   Annual bluegrass persisting in hybrid bermudagrass on a golf course during the winter months. Annual bluegrass stays green during the winter in colder climates while the bermudagrass becomes dormant, dies, or turns brown. Annual bluegrass has evolved.  This grass is very different from what it used to be 50 years ago in many locations. In the old weed control manuals 30, 40 and 50 years ago they all said the same thing. It is a winter annual, the seed germinating toward the end of summer, flowering or producing seed heads during the fall and winter months and the seed laying dormant or sleeping through the summer. It repeats this cycle over and over. Annual bluegrass is a very poor competitor with mulch but it is an excellent competitor when it grows among other grasses. When I went to school, this is what I learned annual bluegrass was.   Annual bluegrass seedhead. Annual bluegrass has evolved in certain landscapes and climates where it now persists as a perennial in warm climates and will produce seed at different times of the fall and winter months. This is very apparent on many golf courses and a nightmare for golf course superintendents. This grass can be mowed very short, 1/4 inch or less, so mowing it out will not happen. It loves environments where the grass is mowed short and kept wet. It is also very strong in soil environments that are compacted without much airspace between soil particles. I would compare it, from an evolutionary standpoint, to the cockroach. Controlling it in cool season lawns. When it grows in cool season lawns, the usual methods of control are pre-emergent weed killers or herbicides. If this is a home lawn, you will have an advantage because you can apply these pre-emergent herbicides several times during the year and that’s what you will probably have to do, starting in late summer and through next spring.  Look at the pre-emergent herbicides available to you and select one that can be applied to a lawn and says that it controls annual bluegrass. Make the first application of pre-emergent herbicide in the middle of late summer. In the hot, southern Nevada climate this would be about mid July or early August. Read the label and it will tell you when to make a second application and how much to apply. In the past, Scotts has made excellent products for weed control in lawns. Pre-emergent herbicides slowly degrade over time. You want to apply this herbicide a short time after its peak control period. It will tell you on the label how many weeks to wait after this first application before the second one is made. There is some residual from the first application so you will make the second application at some rate less than the first application. I repeat, the label will tell you how much to apply and how long to wait before applying the second application. Continue this cycle of applying, waiting and repeating all winter long (if the label allows it) and into early spring. That should kill most of the seed. If you see some young plants that were missed by the herbicide application (they are usually lighter green and grow faster than the surrounding grass) then pull them by hand. They will pull out easily because they have very shallow roots. Annual bluegrass biotype producing short rhizomes, adapting like a cockroach to a changing environment. If this is a bermudagrass lawn, kill the annual bluegrass during the winter months after the bermudagrass has turned totally brown (dormant). Do not overseed this bermudagrass lawn with a winter lawn this year, and possibly the next year, until you get control of the bluegrass. By the way, this is also an excellent way to control other weeds including tall fescue growing in a bermudagrass lawn. After the bermudagrass lawn has turned all brown, and you have mowed it, spray the lawn and the annual bluegrass in it with Roundup herbicide. The Roundup will kill the annual bluegrass because it stays green during the winter months (cool season grass) but the bermudagrass is dead above ground. The Roundup will have little to no effect on the dormant bermudagrass. This is a core aerator that punches holes in the lawn. Management methods that help to suppress annual bluegrass are aeration (punching holes in the lawn with a core aerator) and waiting longer between irrigations during the late summer, fall and winter months. Aeration helps open the soil which annual bluegrass does not like. As I said before, annual bluegrass likes it wet because it has a very shallow root system. Waiting longer between irrigations helps keep the soil dry and minimizes its invasion. Preventing annual bluegrass from entering your landscape and lawn should be done in the future. The seed is transported to the landscape on shoes that walk across the seed heads during the fall and winter months. If a landscape has annual bluegrass and people walk across the seed heads and then walk into your landscape, they will transport the seed and that’s where it starts. It is also transported to lawns in the same way as well as the lawnmower. If a lawnmower was used on a lawn that had annual bluegrass in it and it was seeding, I guarantee 100% that this

Q. You mentioned to drill holes in the trunk of the Cypress and pour a solution into the holes to encourage decay. Can you tell me again what that solution was? I can’t read my own writing! A. I would use diluted Roundup if the tree is still standing and you want to kill it. Use the most concentrated form allowed on label. Either buy it in the diluted form or dilute a concentrated form but do not use it full strength unless it is already diluted.             Drill the holes as close to the ground as you can and at a downward angle. Use something like a syringe or other disposable item to force dilute Roundup down the holes that are freshly drilled. Fill the holes every hour three times to get plenty of chemical in the tree if you want to kill it.Make sure you wear unlined gloves during the application to protect your hands.             There is a product that you can buy which you can apply to the stump after the tree has been cut down. Once the tree has been cut down, drill holes in the stump vertically and fill the holes with this product.The product comes under several names such as Stump Remover, Stump out, etc. Follow the directions on the label. Hope this helps.

Q. Hello again!  I have a puzzling issue happening with a few citrus trees (out of many).  The leaves are curling, yellowing, and ultimately dropping. I attached a few pictures in hopes you could shed some light on the issue. (Any iron deficiencies you see are from trying to extend the time between treatments, something I’ve been trying to perfect; seems like every 6 weeks is the sweet spot.) I appreciate any help you can give me, I’d hate to see these trees die!  Leaf rolling like this on citrus can be a watering problem Add caption A. If the leaves are rolling or curling into a cigar shape, then this is typically a lack of water. The leaves can turn yellow and drop from the tree if it continues. A lack of water can be from not giving each tree enough water or it can result from not watering frequently enough.  Strangely, the same can result if you are watering too often but it almost never results from giving a tree too much water in a single application. My suggestion to you, if these trees aren’t drip emitters, is to make sure that each tree has at least four drip emitters.  Replace these emitters with emitters that double the application rate. In other words, if these are 2 gallon per our email letters, replace them with 4 gallon per hour emitters. This allows you to keep the same number of minutes on your irrigation timer and not overwatering other plants on the same valve.  I would strongly advise you not to use adjustable drip emitters for this purpose. They can be extremely difficult to adjust properly since they seem to act like “whack a mole” when you try to adjust them. Visit this page from the University of Arizona on citrus problems in the landscape

Q. I have a high brick wall in my backyard that has white crystals, or “whiskers”, forming on it.  This is because of the over watering by my neighbor on the other side of the wall.  I asked my neighbor if they would decrease their watering but that hasn’t happened.  I have used vinegar and brushed it off with a stiff brush. I also tried brushing it with a dry brush.  They are not working.  I bought some muriatic acid, but I am afraid to try it because I have plants and trees right by the wall.  I would appreciate any advice you can give me to solve this problem. Soft deposits on a porous wall are “fuzzy” or can look like white whiskers. A.  You are correct.  This white, “powder” or “whiskers” is because of the water coming through the wall from your neighbor.  When the wall dries, white “salts” are left behind on the surface of the wall which were previously dissolved in the irrigation water.              The only long-term solution is to reduce the amount of water applied on the other side of your wall.  Eventually irrigation water coming through the wall and containing salts will undermine the strength of the wall. Phosphoric acid is better for the plants than muriatic acid             I am afraid this is a common problem with no easy solution if your neighbor is not willing to help.  In the meantime, use phosphoric acid rather than muriatic acid to remove white “whiskers” from the wall.  Phosphoric acid is safer to use and the phosphorus contained in the acid is a plant nutrient.              Muriatic acid contains chlorine, also a plant nutrient, but needed in very small quantities by plants compared to phosphorus.  Chlorine can be toxic to plants if too much is available.               Ultimately, your neighbor’s landscape should have a “dry zone” at least 3 feet wide next to this wall.  This dry zone does not have to be void of plants.  It can contain water conserving plants irrigated with drip emitters.  Minioasis landscape design             An even better solution is to convert this landscape to a “desert landscape” using a minioasis landscape design.  Minioasis landscape designs feature high water use areas of the landscape close to the house, located where people like to congregate.  The other areas are designed and landscaped to use less water by having fewer and smaller desert adapted plants.