|I planted a Lagerstroemia indica x fauriei 'Tuscarora' 2 yrs ago. First year it did poorly - wrote off to transplant shock. In 2nd year now, the leaves on old wood came back, but no new growth whatsoever. Like the tree is in a coma. Last year it exhibited leaf edge burn followed by leaf drop. Starting to do same. Figured it was water problem, cut back on water. No help. The soil is clay but was amended. Drainage should be good - as extra wide / deep hole was dug and backfilled. The tree does not have aphids or powdery mildrew. Clearly something is wrong, but can't figure it out. Now I'm thinking that the primary problem is not over/under watering, but perhaps too high alkaline?
I've dug down next to root ball to check moisture content of dirt and seems ok? I do not fertilize it (except when planted - used slow release agriform tablets).
|Crispy leaf margins usually indicate a soil pH problem. Crape myrtles have a tendency toward chlorosis or marginal leaf burn in alkaline or saline soil. Since you've already monitored your watering practices and have been careful with fertilizers, I think the only explanation is soil pH. I'd have the soil tested, either through your local Cooperative Extension office or a private lab. Once the soil has been analyzed, the results will mailed to you along with recommendations for improving it. In Ventura County, contact your Extension office at 699 County Sq. Dr. #100, 93003, phone 805-645-1451. Best wishes with your tree!