Reviving Crepe Myrtle After Neglect

Crepe myrtle with annual fertilizer applications

Q. I inherited an established crepe or crape myrtle tree when we moved into a bank-owned vacant home two years ago.  The landscaping was pretty distressed.  I replaced the rock mulch with bark and the drip system seems to be working fine.  The tips of the leaves are dry and brittle and it blooms very little.

A. You are probably going to have to give this crepe myrtle a jumpstart. It is good you put down a wood mulch with this type of tree. I hope this is wood and not bark mulch.

            Since it is summer now you want it to push some new growth so you can see the tree’s strengths. Fertilizer is okay to apply now to trees and shrubs.

            Use a normal tree and shrub fertilizer and apply it a foot or two away from the trunk and close to its source or sources of water. Water it in with a hose.

            Construct a moat or a doughnut around the trunk of the tree at least 4 feet in diameter and 4 inches tall. This is nothing more than an irrigation basin to hold water. Fill this basin with water from a hose once a week for the next four weeks. Let your irrigation system run normally during this time.

Crepe myrtle trunk and bark

            Let irrigations push the fertilizer into the root area of the soil over the next couple of weeks. At the same time, add an iron chelate along with the fertilizer. The best iron chelate is iron EDDHA. You can find it in most nurseries now.

            When the weather cools off in the fall, around September, spray the foliage with Miracle Gro fertilizer used for the promotion of flowering. Try using a hose end fertilizer applicator so you can get it to spray that high.

            If you can't spray that high, apply it to the soil and water it in.

            Next spring start pruning out the deadwood in the canopy. Don't climb in the tree, but rather I would use a ladder. This is time-consuming because you will be cutting a lot of tiny branches along with some larger ones. Basically you are thinning out the canopy and getting rid of branches on top of each other or crossing each other.

            I question if your tree is getting enough water. If it is a sizeable tree it will require 30 or more gallons during each watering. You will have to look at your irrigation emitters and the time on your irrigation valve to figure this out.