Boric acid in garden to kill roaches? | Salt to kill snails?
NMSU branding

Issue: June 29, 2002

Boric acid in garden to kill roaches?

Question:

I read that boric acid can be used to kill roaches. Can I use boric acid in my flower beds to keep the roaches from coming indoors?

Answer:

Boric acid is effectively used as an indoor treatment for roaches. Use only boric acid whose container is labeled for roach control. As roaches crawl through an area treated with the powdered boric acid, it collects on their legs and body. As the roaches later groom themselves, they will ingest the boric acid and die.

Boric acid is intended for indoor use, not outdoor use. Boric acid can kill your plants as well as it can kill roaches. The boron in boric acid is a nutrient needed in very small quantities by plants. Even a little too much boron is toxic to plants. Most of our Southwestern soils have adequate concentrations of boron, and additions of boric acid can quickly create a toxic situation.

Salt to kill snails?

Question:

I have seen snails killed when salt was sprinkled on them. Can I use salt to kill snails in my garden?

Answer:

This is another case of a product that can kill plants. Snails do die when salted, but so do plants. Sodium is another plant nutrient used in very low concentrations by plants and toxic to plants at slightly higher levels.

Fertilizer will do the same thing to snails and slugs as table salt will do. You can sprinkle a little fertilizer on them and they will die. The fertilizer won't hurt plants unless you overdo the snail treatments. Too much of any salt (and fertilizers are salts of plant nutrients) will harm plants. Fertilizers are nutrients that don't become toxic as quickly as boron or sodium. A band of fertilizer placed several inches from tender plants after irrigation will help protect from snails following irrigation. For severe snail and slug infestations, it is better to use other methods to control snails to avoid over-fertilizing the garden and harming the plants. Other methods include the stale beer snail/slug traps and chemicals labeled to kill snails and slugs.

back to top

Also, please join us on Southwest Yard & Garden, a weekly program made for gardeners in the Southwest. It airs on KRWG in Las Cruces Saturdays at 11:30 a.m., repeating Thursdays at 1:00 p.m.; on KENW in Portales on Saturdays at 10:00 a.m.; and on KNME in Albuquerque on Saturdays at 9:30 a.m.

Send your gardening questions to Yard and Garden, ATTN: Dr. Curtis Smith NMSU Cooperative Extension Service 9301 Indian School Road, NE, Suite 112 Albuquerque, NM 87112

Curtis W. Smith, Ph.D., is an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. New Mexico State University is an equal opportunity/affirmative action employer and educator.

Please join us on Southwest Yard & Garden, a weekly garden program made for gardeners in the Southwest on: KNME-TV Albuquerque at 9:30 p.m. Saturdays, KENW-TV Portales at 10 a.m. Saturdays, and KRWG-TV Las Cruces at 11:30 a.m. Saturdays (repeated at 1 p.m. Thursdays.)