Marin Master Gardeners
University of California
Marin Master Gardeners

What Happens to Garden Bad Guys in Winter?

garden bad guys
There’s one thing that gardeners in freezing cold areas can boast about: many of their pests cannot survive the low temperatures. No such luck around here. Marin winters are mild enough that many pests survive the occasional frost or rain storm to live on into spring. They overwinter in varying states of developments — as adults, immature insects, or eggs — and emerge or hatch when things warm up in the spring. Unfortunately, this is often the time when  and plants are young and easily damaged.

This early infestation allows the pests to gain a foothold in your garden, which can make control difficult. But early infestations are frequently the result of late season infestations. What does that mean? It means that iIf you had a squash bug problem late in the season this year, it is likely that you will likely have squash bug problems next year. The adults overwinter in plant debris and other protected areas near the garden area and emerge early in the spring to begin feeding on young plants, mate, lay eggs and the damage cycle begins.

Clean Up Your Garden

The best jump start for ridding yourself of uninvited insect pests is to clean up your garden after every growing cycle. This helps reduce the number of next year's pests. Properly cleaning up in and around your garden this fall and winter can greatly reduce potential insect and disease problems. Piling up old vines, plant debris, and trimmings in or near the garden creates a perfect environment for insects to hide out and stay warm when the weather turns cold. Remove garbage cans (full or empty), tomato cages and stakes, hoses, and anything else that provides a winter hotel for pesky insects.

Diseases can be reduced by removing plant material that may be carrying spores and other undesirable disease organisms who are perfectly satisfied to overwinter in the garden. This is important for both annual and perennial fruits and vegetables. Many disease organisms can survive the winter not only on plant debris but also in the soil. When splashing water jettisons them onto plants, infection may occur.

For more information, visit the UC IPM website on invertebrate pests - http://www.ipm.ucdavis.edu/PMG/invertebratelist.html

Webmaster Email: banielsen@ucanr.edu