Q. We have nine pine trees and they are dropping lots of needles. We have a large berm under the trees and water inside the berm twice weekly. Should the needles be removed or left in inside the berm? A. The needles are fine. If composted, they are said to be slightly acidic and will benefit our alkaline soils. If they are left alone in the basin, they will help mulch the soil, conserve water, reduce weed emergence and benefit the soil in general.             A lot of needles blew out of the trees during the last storm event we had.  This is a normal occurrence and nothing to worry about. Pine needles die for lots of reasons. Sometimes it is just old age. Some pines can keep needles on limbs for five years or more. Others only about three. They stay loosely attached or caught in the limbs even though they are dead. A big wind comes and blows them out of the canopy.             If pine trees are getting plenty of water and fertilized once a year they will have a thick, lush canopy and grow about 12 to 18 inches a year. If water is not enough, they will not grow as much and not have a dense canopy. They will survive like that but just not be as thick and lush.             Your berms should extend three to four feet from the trunk and deep and level enough to hold about three to four inches of water. Your watering frequency sounds right. Just make sure it gets enough water each time to move into the soil two to three feet or more. In sandy soils water needs to go deeper and more often.

Q. We actually took off the last tomato early this week.  Not fully ripe, but took it inside so no bugs or others would get to it. Somewhere I remember reading that you can cut them back to 12-16″ and they will grow again.  A. You can cut them back to some side shoots now but it will open the plants to sunburn if you are not careful and the plant may die. It is possible to cut them back now while it is still hot but make your cuts so that you reduce their height and still leave plenty of side shoots. Sunburn on tomato on fruit and leaves.             Another possibility is for next year. Try planting some from seed in early to mid-July. Put the seed between the plants and cover the soil and seed with straw to keep it moist and hand water daily. Make sure you mix compost into the soil in the spots where you planted the seed. Soak the seed in water four to six hours before you plant it. This will speed up germination. In about late mid to late August, cut or remove your old plants and let the young ones come in for production in September through November.             Stake or trellis the plants and thin side shoots so you have better air circulation. Reduce any winds you have on the area with wind screens or windbreaks. Make sure you have at least 6 to 8 hours of full sun, fertilize lightly every 30 days AFTER you see flowering.

Q. I have read over and over that African Sumacs are fast growers. The African Sumacs here seem to be at a stand still! I have two in my backyard since April. They are alive but the canopy and trunk just seem the same, perhaps 10% growth. The trees are sold with tall, thin trunks – like 1/2 to 3/4 ” diameter, with a canopy that branches out at 8 feet. There are no branches or leaves below that. The trees are staked high and the stems are all finger diameter. Will they take off eventually? A. Trees with a long, skinny trunks with no side branches until 8 feet are a problem. This is done at the wholesale nursery to increase their height and make it easier to ship. It is to their advantage, not to yours.             To have strong trunks, tree trunks to be tapered from top to bottom. In other words, to have good trunk strength the trunk needs to be bigger in diameter at the bottom and get narrower up the trunk. This helps to support the canopy. If they don’t, a good wind will come along and snap the trunks.   Trees with no taper cannot support their own canopy. Leave any growth on the trunk that develops and stake as low on the trunk as you can to allow the trunk to move. Both of these things will help develop a tapered trunk.             Trees develop tapered trunks from two major events in their lives; trunks swaying back and forth in the wind and the presence of branches with leaves all along the trunk. Both have a great deal to do with trunk taper and consequently its strength.             When trees are staked, trunks should be immobilized no lower than it takes to hold the tree upright and still allow some trunk movement. The stakes should be removed as soon as possible after planting; usually no longer than one full season of growth.             Next, never, never remove branches growing along the trunk if they are smaller than pencil diameter. Once these stems reach pencil diameter or thereabouts, cut them off flush with the trunk with a clean, sanitized bypass-type pruning shears.             Never plant in a DRY hole. Make sure the soil in the hole is wet when tree roots come in contact with it. Planting in a dry hole can set a tree back, or any plant for that matter, due to root damage.             Sometimes people say this is “transplant shock”. Well, yes, plants do have a setback, or shock, when removed from a container and placed in the ground. This can happen for many reasons but the DEGREE of setback can be under your control.               Why are they growing so slow? The amount of total growth on a plant (add up all new growth above and below ground) is divided by the number of places where growth can occur. Stems in full sunlight or without competition from other branches will usually be the strongest in growth but the total growth must be divided among every place that is growing. This includes the roots and any increase in the diameter of stems and trunks.             If you want a plant to grow faster, reduce the number of places where growth occurs. Prune out unnecessary stems so that the growth is focused on those stems where you want growth to occur.             You may see sprouts coming out of the trunk. Leave them. Do not prune them out until they are pencil-sized or larger but leave the small ones to help build caliper or taper.

Horticulture specialist Bob Morris says you can grow anything in the desert – Las Vegas Sun News

I have been impressed with discussion groups. Members can add comments and their own experiences. There are lots of you out there who could contribute and lots of us will also learn in this exchange. If you have an interest in helping our desert dwellers, new and old, and learning in the process please join me in the Yahoo Discussion Group – Desert Horticulture. Xtremehort aka Bob Morris   We had 85 people look so far, and only three people join.  

Japanese Eggplant descriptions Millionaire. Very popular eggplant variety. Black-purple fruit about 8 inches long is an early producer. One of the most popular Japanese eggplant hybrids sold in markets. Senryo ni  gou. Excellent for home gardens in Japan. Glossy black oval fruits to 5 inches long and weighing about 1/4 pound. Good for pickling. Shoya long. Purplish-black fruit up to 14 inches long and purple calyx. Early producer for stir fry, grilling and tempura. Yasakanaga. Purple-black fruit to about 7 inches long with purple calyx. Grilling, stir fry and tempura.   Mizuno takumi. Popular with chefs, purplish-black oval fruit weighing about 1/2 pound. Used for cooking or pickling.  Very popular in Japan. Kyoto egg. Supposedly heat resistant according to seed catalogs but most are good producers during the heat. Round fruit to about 3 inches in diameter. Stir fry or deep frying, grilling. Purple calyx. Kurume long. Ten inch long black fruit with purple calyx. Produces a bit later but prolific when it starts. Open pollinated. Konasu. Very small round dark purple fruits with purple-black calyx. Can be cooked but popular for pickling when young, stir fry and grilled in a kabob. Kamo. Round fruit with flat bottom and purple-black skin weighing up to 1/2 pound. Very well-known eggplant in Japan.   Ping Tung. Chinese eggplant that is purple-black up to 18 inches long with green black calyx. Good producer. Black Beauty. Large purple-black fruit but slow to yield and low yielding but excellent quality. Thai Long Purple. Very long, purple black fruit with green calyx. Very good quality and good producer.  Thai Long Green. Fruit is similar to Long Purple but green. Similar quality. Green calyx. Thai Yellow Egg. More of a novely or decorative eggplant. Fruits are golf ball sized and lemon yellow when ready to pick.

Q. I have two gardenias in the backyard in 15 gallon ceramic pots with good drainage. One of them is doing pretty well and the other not so well. Our backyard is on the north side so both are shaded most of the day. The picture I sent to you has leaves turning yellow and then brown on the interior of the plant although the ends of the branches still have green leaves. Both plants are on drip and watered the same. I added iron on top of the soil and also Vigoro 10-8-8 plant food but it doesn’t seem to be helping. The one I planted about 6 weeks ago has not done well. The other one was planted 3 months ago and is doing well with lots of flowers in May. Any suggestions for the one with the yellow leaves?  Gardenia leaves yellowing in potted gardenia. This could be salt accumulation. A. It is tough to acidify soils here in our desert due to the alkalinity of our native soils and our water. So if you can acidify the soil as best as you can, it will help. Ways to acidify the soil include using composts, raw composts, manure products, sulfur, acids and aluminum sulfate. My best shot at the gardenia is iron even though you added some. If you don’t use the right iron, it may not work. Use an iron chelate such as EDDHA with iron. You can pick up a one pound canister of this iron chelate locally at Plant World. I don’t know any other place it is being sold. Combine it with a soil application of your Vigoro fertilizer. You might also consider some of the Miracid products. Try to use fertilizers specially made for gardenias in the future if you can find one. If you can’t, use one for azaleas and rhododendrons. If you can’t find that, a third choice would be to use one for tomatoes, fruit trees or roses. Fertilize about once a month during the active growing season. These should be very light fertilizer applications. Whenever you are watering a plant in a container, you want to add enough water so that about 20% of the water runs out the bottom. This helps keep salts leached from the soil. Our tap water coming from the Colorado River is quite salty and you need to make sure the soil stays flushed of salts coming from the water. If you don’t, these salts will build up in the container soil and also cause exactly the problem you describe. You can’t let the soil go dry so it might be a good idea to buy one of those inexpensive soil moisture meters used for house plants which can give you a rough idea when the soil is dry and you should irrigate. You want the soil to dry down between waterings but not too much. If it doesn’t dry down, you may develop root disease problems on camellias. If you let them get too dry, they will drop leaves and the remaining leaves will become scorched. It is hard to judge when container soils are going dry. One way is to get an idea of its weight. You don’t have to lift it but just budging or moving it a little can give you an idea.

We need expert opinion soon about what to use as fertilizer for Greenway grass, bushes, and trees. Your advice please. Greenway grass Q. What is the range of N-P-K in cow manure that some landscapers use for grass? A. It’s really not fair to compare cow manure to a fertilizer because it really isn’t. They are using it more as a top dressing than as a fertilizer application. Manures vary in fertilizer content but are generally about 4% nitrogen and usually low in phosphorus and potassium. You should not rely on cow manure as a fertilizer. The fertilizer should be applied separately from a cow manure. An inexpensive fertilizer for starting plants and getting root growth from seeds, seedlings or newly planted trees and shrubs is 16-20-0 or DAP (18-46-0). Q. What inorganic fertilizer would you recommend and the amount/acre? A. For turfgrass you should never apply more than 1 pound of nitrogen every 1000 ft.² or 43 pounds of nitrogen per acre. In my opinion, this is excessive and should be closer to 1/2 pound of nitrogen per thousand square feet or 22 pounds of nitrogen per acre. This would be for inexpensive, quick release agricultural nitrogen fertilizers. If you are applying more expensive horticultural fertilizers that contains slow release nitrogen, then you can bump it up. How much to bump it up depends on what percentage of the nitrogen is slow release in the fertilizer.    Q. Use 10-10-10 at 500lbs/acre maybe? A. The fertilizer you mention has 10% nitrogen. It is not a good turfgrass fertilizer but it’s fine for trees and shrubs. In fact, turfgrass fertilizers are fine for trees and shrubs as well. The best turfgrass fertilizers are in the ratio of 3-1-2 or 4-1-2. An example would be 21-7-14, a 3-1-2 fertilizer. To apply 1 pound of nitrogen requires 10 pounds of fertilizer. Using your fertilizer you would apply 430 pounds of the fertilizer to get 43 pounds of applied nitrogen. Like I said, I think this is excessive and you will not see the difference once you exceed three quarters of a pound of nitrogen per thousand square feet or about 33 pounds of nitrogen per acre. In fact, if you apply 1 pound of nitrogen per thousand square feet it will push turfgrass growth quite rapidly. Q. How many times per year and which month(s)? A. For tall fescue turfgrass I would apply nitrogen four times a year; Labor Day, Memorial Day, Fourth of July and Thanksgiving. During the hot summer months I would always make sure you do not exceed 1/2 pound of nitrogen per thousand square feet or you could end up with some burning if people are not careful. If you are using mulching mowers you can skip the Fourth of July application. If you are using mulching mowers you should never exceed 1/2 pound of nitrogen per thousand square feet in a single application. Q. Should a roller of punchers be used immediately after fertilizing? A.I assume you mean aeration. Core aeration can be done any time of the year and does not really relate to a fertilizer application. The only exception might be when you are applying a high phosphorus fertilizer.                            Q. Should organic fertilizer (cow manure) even be used to fertilize grass? A. Cow manure is not a fertilizer. Bushes Q. What inorganic fertilizer (N-P-K) would you recommend and the amount/bush? A. Turfgrass fertilizers in the ratio I mention above are good for most trees and shrubs. You would apply this fertilizer in the very early spring or late winter. The amount to apply is similar to the amount you would apply to turfgrass but is calculated under the canopy area of trees and shrubs. A small tree that occupies 100 ft.² of canopy space would get 1/10 of a pound of nitrogen. A tree that had 1000 ft.² under its canopy would get 1 pound of nitrogen. The driver of growth for trees, shrubs and turfgrass is nitrogen. Q. Applied dry, or liquid, in the gravel around bushes? A. Dry fertilizers are applied near the irrigation source. If trees and shrubs are irrigated by sprinklers, then you distribute the fertilizer so that the sprinklers pushed the water into the rootzone. If these are drip irrigated, it is applied in the soil next to the drip emitters and the water carries a fertilizer into the rootzone. If you are applying a liquid fertilizer to the foliage obviously you have to wait for the foliage to appear in the spring to make an application. If this is a liquid fertilizer applied to the soil and make the application close to the drip emitters within a few inches under the mulch or under the turfgrass. Never apply a fertilizer to trees and shrubs deeper than about six or 8 inches. Fertilizer spikes are convenient but expensive. Liquid applications to the foliage last about 4 to 8 weeks. Dry fertilizers applied to the soil last longer if that’s important. Q. How many times per year and which month(s)? A. Most trees and shrubs will require a single application of a fertilizer to the soil during the months of December through about March. In a pinch you could go as late as April. Some plants tend to get yellow due to iron chlorosis or a lack of available iron. Usually a single application of an iron fertilizer that contains the chelate EDDHA is enough to keep them from yellowing. If these plants have been yellowing and are in poor condition for several years, this will probably not work in correcting a severe problem. The iron fertilizer should be applied at the same time as the other fertilizers, in early spring or late winter. Tall trees Q. What inorganic fertilizer (N-P-K) would you recommend and the amount/tree? A. You can use a good turfgrass fertilizer for most tall trees and shrubs. To be effective this fertilizer should be applied close to a source of water for the trees so that it is

Q. We are planning a wall to surround our yard so we can keep the rabbits out.  We live in Sun City Anthem in Henderson. We have been told that the local rabbits can jump very high, and our 3 foot wall will not work to keep them out. A. We have both the Desert cottontail and the jackrabbit. I don’t agree with the advice you were given. Our chicken coop wire at three feet tall was very effective at keeping them out of our vegetable plots as long as they could not lift the bottom edge of it with their noses or dig a little bit and get under it. Black-tailed Jackrabbit             Usually animals will not jump walls if they cannot see the other side. If they can jump to the top of it and look then that is different. I have never seen rabbits do that. But check and make sure there are not gaps in the wall itself. If they can get their head through a hole, they can get the rest of their body through it as well.

Q. My Australian bottle tree and African sumac are shedding leaves like a maple tree during fall.  However, they are also putting on new growth.  I specifically chose these trees because they remain green all year long. The bottle tree is about 20 ft. tall, on the north side of the house and gets about 20 gallons of water every day during the summer.  The sumac is on the west side and is about 12 ft. tall and gets about the same amount of water.  I’m about ready to cut them down due this leaf shedding. Were they stressed during the heat wave or what? A. These two trees have very different watering requirements. The bottle tree is a true desert adapted tree while the African sumac is not. Their watering needs are very different for this reason.             The bottle tree should never get daily watering. Even though the watering needs of the African sumac are more frequent, it should not get watered daily either. It is possible that these trees are dropping leaves excessively because their roots cannot “breathe” due to excessive moisture in the soil. Bottle tree in desert landscape             At the most, the sumac should get watered deeply twice a week right about now. The bottle tree less often than that but when it does get water it should be deeply as well.             Evergreen trees do drop their leaves. No plant is without leaf drop. Some keep their leaves longer than others.             Normal leaf drop time for evergreen plants is during or shortly after new growth. As they put new growth and new leaves on new branches they drop older leaves from older wood. This is normal. However, excessive leaf drop is not. This can indicate stress ranging from drought to overwatering.             Please get on a deep and infrequent watering schedule rather than a daily one. This time of year the only things watered daily are fescue lawns, annual flower beds and vegetables. The larger the plant, generally speaking, the deeper the root system, the less frequent the watering but the amount of water applied each time is higher.             Frequent, shallow irrigations force roots to grow shallower and decrease their tolerance to droughty conditions. Both of these trees can develop root rot from frequent watering and death. Excessive leaf drop can be a sign that this is happening. Bottle tree in lawn             I would begin to back off to watering every other day for right now but increase the amount you give them each time you water. Both can handle the heat but not daily watering, particularly the bottle tree.             Make sure the applied water is distributed evenly under the canopy either by having several drip emitters under them or watering them in a basin and flooding the basin. The water should not be applied in one location under the canopy. Back off on the daily watering. I hope they are not in stages where you can keep them from getting worse.