mulch

Q:  I have heard that mulch from the hurricane areas has been sent here and it is full of termites.

A:  Faith M. Oi, Assistant Extension Scientist, University of Florida, Entomology and Nematology Department offers the best answer and I am using part of her response to answer your question. “…the greater risk to structures is from termites already established in your yard as opposed to any termite stragglers that may be brought in on bags of mulch.”

Termites can be found in mulch, but their survival is poor and here’s why: The ability of the termites to survive the chipping process to create mulch is not good; additionally, once separated from the colony, their ability to survive further decreases.  Finally, even when termites are found in mulch, mulch-fed termites suffer significantly lower survivorship.

In terms of spreading invasive species like the Formosan subterranean termite, the greater problem is associated with the transport of large chunks of wood containing enough termites to sustain reproductive forms.  For example, infested railroad ties used in landscape or salvaged timbers from razed structures are known to be associated with the spread of the Formosan subterranean termite.  Mulch increases the ability of termites to survive where they are already established by keeping the soil moist and temperatures moderate.  Mulch laid too thickly (>4-6 inches) can also provide a “bridge” over the treated perimeter of a house, allowing termites to walk over from landscape to house and avoid contact with soil treated with termiticides.  If mulch is part of your landscape, I recommend a thin layer (<2 inches) of mulch be placed within 12 inches of the foundation to allow the soil beneath to naturally dry.

Desiccation (dehydration) is the termite’s worst enemy.  Also avoid watering next to foundation walls. So bottom line, don’t panic, use mulch but away from your house foundation and only 2 inches deep.  For more information about the Formosan termite check out:  http://edis.ifas.ufl.edu/in278