Transplanting season near its end

When transporting it in your car, keep it out of strong winds. At home, try to provide as much sunlight as you can and keep it out of strong drafts. Never let the soil become dry, but do not keep it soggy, either. If you have to, buy a soil moisture meter and use it to help determine when to water. Fertilize the plant lightly once a month during an irrigation or use houseplant fertilizer stakes.

Q: I wish to transplant a lilac bush. It is facing west and struggles during the heat of the summer. I believe a better spot is on the north side of a south wall with more shade. I would like to transplant it now while it is cool. Is this the time?

A: In cooler climates, lilacs can be planted in full sun and withstand it all day long. You are right, in our climate your lilac will do better in a different location. But if it is too shady, it may not bloom very well, if at all.

Morning sun is typically less damaging to plants than afternoon sun during the summer. Plants that produce flowers typically need more sunlight than those that we appreciate just for their foliage. If it is possible, try to find a spot where the plant can receive full sun in the morning and shade in the afternoon.

Regarding transplanting this time of year, ideally there should be some root growth after transplanting. Root growth is very dependent on soil temperature, with very little of it occurring when temperatures drop into the 40s . And, you are planning to move the plant from a place that has warmer soils than its new home.

Plants are easier to move by hand if they have been in the ground less than three years. It seems to me that once they hit that three-year mark, the root system can be very established and make the plant difficult to move. Plants watered by emitters close to the trunk are easier to move since most of the roots have restricted growth.

Unless you can be sure that you can take a very large root system with the plant, I would wait until spring.

What you can do to make moving the plant in the spring more successful is to root prune now. Take a sharp shovel and slice the root system just to the inside of the root ball that you will be moving. This will sever the root system, causing it to regrow closer to the plant.

Since it is on the tail end of transplanting season, this is kind of a judgment call. I hope I have given you enough information to make a decision.

Be careful when you buy lilacs. You have to plant lilacs with low chilling requirements if you expect them to bloom in our climate. Common lilacs may not bloom in the lower elevations of Southern Nevada because they do not get enough cold during the winter to form flower buds. Low chilling requirement lilacs such as Lavender Lady or Angel White will bloom here. You also may want to select Persian or Chinese lilacs instead of common lilacs.

Q: I sent you a picture of my tree. This tree was beautiful at the end of August and now it seems dead. I checked the drip system and it is working. Also, there are suckers growing from the base of the tree. If the tree does not come back, will any of these take over enough to regrow the tree? What kind of tree is it?

A: From the picture, the tree looks like an acacia. In any case, it is one of the desert legumes similar to an acacia, palo verde or mesquite. You can see pictures of this tree in my weekly newsletter (To get the newsletter contact me by e-mail at Morrisr@unce.unr.edu or call me at 257-5509.).

It is very puzzling why your tree would suddenly die. I don’t have an explanation.

There is a very large beetle, the palo verde root borer, that feeds on the root system of desert trees but I don’t think it would cause that to happen all at once. It would have died back gradually.

Push on the tree rather hard to make sure the root system is still viable. The tree should have no movement in the soil if the root system is healthy. If the tree is solid in the ground when you push on it, you will probably have luck cutting it back and letting it regrow from the root system. If the tree moves when you push on it, it would probably be best to replace the tree.

To have it regrow as a single-trunk tree, I would cut off the trunk at a place where it is still healthy. Even if the trunk is healthy at 4 feet, I would cut it at about 2 feet.

If you want a multiple trunk, which I think is a prettier form anyway and fits the habit of this tree, you would cut the trunk a couple of inches above the new growth. You would not do this until about early February. Cutting it now would be a mistake.

When you do cut the tree, it would look nice with three to five trunks growing from the base. I would have no more than seven because then it begins to resemble a shrub. Pick the strongest limbs and remove the rest when they are very young. This will concentrate the growth next season into the remaining limbs.

You can probably rub off or pull off undesirable growth as you see it emerge from the trunk; pulling is a better method for removing new growth than pruning when the growth is quite young.

After the initial selection of limbs, I would not prune the tree anymore for about three years except to remove any suckers from the base. After three years, you can begin to prune the tree to remove undesirable growth from the canopy and to shape it.

As for watering, you need to get three or four drip emitters a distance of at least a foot away from the trunk. I would probably put emitters in a square pattern around the trunk at a distance of about 18 inches.

Even though acacia is a desert legume and can manufacture its own source of nitrogen, I would fertilize this tree. You can use tree fertilizer stakes; put a stake under each drip emitter so that the water moves the fertilizer to the tree roots.

Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by e-mail at extremehort@aol.com.