Q: I have a group of loropetalum shrubs which are not doing very well. What could be wrong with them?
A: Several people have called in telling me they are experiencing problems with this shrub. While some of the species seem to be doing quite well, others appear to be dying limb by limb. First, be sure the shrubs are not planted too deeply. You should easily be able to pull the soil off the major roots coming directly from the trunk. Remove excess soil from the top of the roots which will enable them to have access to oxygen. Leave an area about 18 inches or more with nothing but a few inches of soil and air – keep mulches away from the trunk tissue. The mulch depth should only be about 2-3 inches. Change out any over head irrigation heads so the water only reaches the roots allowing the leaves to stay dry. Watering shrubs once every few weeks would be sufficient for any established woody ornamental.
Loropetalum has been encountering problems within the last few years which include stunting, defoliation and sometimes even death. We currently recommend planting ‘Burgundy’, ‘Plum’, or another cultivar with similar characteristics (e.g., red/purple new growth, pink flowers) to ‘Ruby’, since there have been no reports of widespread decline for these cultivars in Florida. Loropetalum ‘Ruby’ is a small (3-5 ft tall), rounded plant with leaves that are more rounded and pink flowers that bloom year round. Loropetalum ‘Burgundy’ (also called ‘Sizzling Pink’) will stand more upright than ‘Ruby’ and grows to be 6-10 ft tall. Loropetalum ‘Burgundy’ has elongated, pointed leaves that turn bright red in the fall and flowers that bloom intermittently.
For best results, UF/IFAS suggests an application of a 5-2.5-100 Cu/lime mixture. To create this mixture, add 5 lbs powdered copper sulfate pentahydate and 2.5 lbs fresh hydrated lime to 100 gallons of water. Spray each individual plant thoroughly. When using any foliar Cu treatment, avoid spraying surrounding plants as phytotoxicity may occur. These materials can also cause damage to metal surfaces such as cars, lawn furniture, etc. In addition, applicators should wear appropriate personal protective equipment when applying foliar Cu sprays. This information came from a publication for Central Florida but we have been experiencing the same issues here in Northeast Florida. http://edis.ifas.ufl.edu/ss477