Home Landscape with Magnolias and Rock

Q. We moved to Las Vegas four years ago and had a professional landscape our backyard. We now have eight magnolias as well peach trees throughout our backyard surrounded by large rock up against the trunks. This rock makes it difficult to fertilize the trees and pick the fruit. Our gardener told us the trees are not getting enough water. Should I pull the rocks away from the trunk of these trees and put wood mulch around their trunks?    

A. First off, both peach trees and magnolias will not like the rock laid on the surface of the soil and surrounding the trees. You will see them start to suffer from this practice in three to five years. Both prefer an “organic” mulch that can decompose into the soil and improve it. That means a four-inch-deep layer of woodchips.

            When buying peach trees, they should be on a semi-dwarfing rootstock such as Citation. If bought on this dwarfing rootstock, they can be planted about ten feet apart, pruned to keep them small, the soil enriched with a good quality compost at planting time and the soil covered with four inches of woodchips, not rock. So yes, pull the rock back about three feet from the trunk and lay down four inches of woodchips instead.

Young magnolia planted in fescue lawn in Las Vegas.

            Magnolias? Eight of them? Wow. I’m assuming you are talking about southern magnolia with its beautiful flowers. Even in Georgia, where they belong, one specimen tree is more than enough for a large yard. Magnolias growing in Georgia can get 75 feet tall with a similar spread! These trees are NOT meant for backyard, or front yard, landscapes (desert or no desert) unless you have a huge property and water is cheap.

            As these trees get older (if they do) they will become a nightmare to maintain and water. Get rid of them now before they get fully established. One tree is enough to satisfy your curiosity and you will probably remove it in less than ten years anyway.

            Let’s say you keep the rocks. Using large rocks around plants has both pluses and minuses. If they are large enough, fertilizer or compost can be flushed on to the surface of the soil by washing it through the rock with a stream of water from a hose. Large rocks are also great for keeping people out. But you are right. Large rock makes it difficult to harvest and prune fruit trees. In my opinion, rock larger than 3/8-inch diameter is difficult for walking safely.