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.