Termites are common in landscapes in our area, and while they may be present in mulch, they won't automatically pose a threat to home structures. Mulch helps the soil surface retain moisture/humidity, which termites require since they are vulnerable to drying out, but the benefit to soil health and plant roots of using mulch outweighs the appeal to termites. They can't subsist on the mulch as a food source, so are only using it as a sheltered foraging environment. Termites are also preyed-upon by ants, so if there are any ant nests in the garden bed, that should help suppress any termite activity.

Don't use a barrier between the mulch and soil. This risks detrimenting plant health by potentially interfering with sufficient moisture and oxygen reaching roots, and will also retain even more humidity underneath the barrier. For root health, mulch should usually be kept between about 1 inch and 3 inches deep.

Yes, you can pull mulch away from the foundation a bit to expose bare soil so termites are less likely to traverse that area and onto the houses. This may allow weeds to colonize the area instead, though, so there is no perfect solution for the strip of ground immediately abutting the home. We don't have an exact measurement of how far the mulch should be moved away; a foot is likely plenty.

We do not recommend the application of an organic pesticide. One of the aspects of these types of chemicals is that their environmental persistence is relatively brief (which is why they're less harsh on beneficial organisms), which means their impacts on termite activity (if any) will similarly be very brief. It would be more effective and practical to consult a pest control professional about using bait stations to monitor termite activity before a decision is made to treat the home perimeters. Such treatments usually last for years and are applied to soil, not mulch, and are relatively targeted so few other organisms should be exposed to the insecticide.

If you'd like help with selecting a professional, the National Pesticide Information Center offers tips for Selecting a Pest Control Company, and the Maryland State Pest Control Association has a searchable database of local, licensed experts. (Members of this association are not your only option.) As with any hired consultants, you can always seek a second opinion of one inspector proposes an expensive plan of action. As with tree-care specialists, different individuals can take different approaches based on their own experience.

Regrading the soil up against the foundation shouldn't be necessary for the sake of termite activity alone, but if moisture pools against the home's foundation due to poor drainage, this is an issue that should be corrected for other reasons (home structural integrity and mold issues, plus root health for the garden bed). The process of regrading might damage the roots of desirable plants in those planting beds, so be aware that if this step is taken, they might need to be temporarily moved beforehand or replaced if they decline after construction. Some plants are much more tolerant of root disturbance than others, so it's hard to predict which plants would succumb to stress in this case.

Additional information about termite prevention and mulch impacts that may be useful is provided by these resources:

• Termites - Preventing Problems in Existing Homes - NC State Extension
• Does landscape mulch lead to termites in your home? - Iowa State Extension
• The Facts About Termites and Mulch - Univ. of Florida Extension

Miri