Q. My friend has a lantana plant and the leaves look good from the top to about the bottom few inches and then they turn yellow. What might be the cause of this condition? My lantanas are getting very thin and "leggy". Do you think I should wait until December to cut them to the ground as some say?
A. These plants originate from wetter climates and richer soils. As these plants get older and woodier at the base, they tend to lose their leaves toward the bottom and keep the leaves on the more succulent stems and new growth.
|Different Lantanas for home landscaping in the desert|
This is worse if the plant is not in full sun or if it is very dense. Regular applications of fertilizer helps along with correctly pruning the plant. Prune these plants to within an inch or two of the soil surface in February if they are leggy. They also need plenty of water so if water is being restricted they will also look pretty bad.
|Pruned Lantana 2 to 3 inches high in February if there is cold damage or it has become leggy|
Lantana loves full sun and do very well provided the soil has been enriched and it is receiving fertilizer. If planted in rock mulch the soil will become mineralized or lose its organic matter content over time and the plant then does poorly.
Get lantana on a schedule every couple of months with a decent fertilizer for flowering plants. In the spring apply compost or composted chicken manure or something similar around the plant and water it in thoroughly with a hose. You want to re-build some organic matter back in that soil again.
I had several reports of grubs feeding on the roots of these plants. When this happens, the plant begins to decline. It might not be obvious to you unless you dug the plant up and examined the soil.
If you believe this could be a problem, you would apply a granular insecticide or a liquid drench around the outside perimeter of the plant. Granular organic insecticides containing rosemary and thyme oil work as well as conventional insecticides containing imidicloprid.