Q. Something has been eating my seedlings out of my vegetable garden. Most of them have just disappeared overnight. How can I figure out which creatures are responsible and how to stop them?

Seedlings are attractive to more than a few critters. During the day, birds will pull out tender young plants. They can be easily be deterred by row covers or bird netting. Nighttime thieves are a little trickier to figure out.

Rabbits are very destructive to vegetable gardens. (I am sympathetic to Mr. MacGregor, Peter Rabbit’s nemesis.) Once the sun goes down, the cotton-tailed marauders emerge in surprisingly large numbers to devour everything within reach. I once foolishly planted over 100 pansy plants in my yard, only to lose all of them to bunnies in one night. 

If rabbits are the problem, fencing can help. Motion-activated sprinklers and rabbit repellents may work as well. Trapping and/or poisoning may be tempting, but barriers and repellents are more effective. 

Snails and slugs, also nocturnal, are notorious seedling eaters. Look for their telltale silvery slime trails. They like to hide during the day, usually under pots, debris, and other dark moist spaces. If you can figure out their hiding spots, you can readily exterminate them. We found hundreds of slugs on the underside of a terracotta planting bowl. After a couple of rounds of scraping, we took care of our slug problem. Bait is also effective, but I recommend using iron phosphate (Sluggo) rather than metaldehyde. Iron phosphate is more expensive but is environmentally friendly and not poisonous to pets. If you’ve purchased decollate snails (small, pointy-shelled predatory snails used to control brown snails), you’ll want to skip the bait since it will kill both kinds of snail. Hand-picking and dropping into soapy water is the safest way to dispose of snails and slugs.

Pill bugs and earwigs will also eat seedlings but are usually only active at night. Wait until shortly after sunset and look for them lurking under mulch, fallen leaves, or other moist hiding spaces. If they’re scurrying around the scene of the crime, they could be your culprits. Trapping is the most effective way to deal with them. Bury a straight-sided flat can (such as a tuna or cat food can) so the top edge is at ground level. Bait the trap with beer or a sugar water/yeast mixture (the smell of fermentation attracts both earwigs and pillbugs). Check the traps every morning and replace the bait in the evening. Another alternative is to use vegetable oil with a few drops of bacon grease as bait. If using the oil/bacon grease bait, I recommend using a covered container that is not accessible to cats or other animals. Just punch a few holes in the top of the container to allow only the earwigs and pill bugs through. Believe me, you do not want your cat or dog to get into the oil/bacon grease bait!

Los Angeles County

[email protected]; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/

Orange County

[email protected]; 949-809-9760; http://mgorange.ucanr.edu/

Riverside County

[email protected]; 951-683-6491 ext. 231; https://ucanr.edu/sites/RiversideMG/

San Bernardino County

[email protected]; 909-387-2182; http://mgsb.ucanr.edu