In our last article (“Gardening Undercover,” March 13), we suggested ways to protect your vegetable garden from slugs, snails and other pests by using physical shelters. There are other great ways to control pests, like inviting amphibians into your garden. After all, frogs and their kin live and hunt on the ground where most pests live and do their dirty work.
Frogs and toads (dry skinned frogs) enjoy dining on slugs. Our most common frog here on the North Coast is the Pacific tree frog (Pseudacris regilla), a small green frog that eats mostly slugs, worms and insects. It is more adaptable to urban/suburban environments than other frog species, and can complete its tadpole stage in ditches, ephemeral ponds and wildlife ponds.
I suspect nearly anyone with a garden on the North Coast has the potential to host the Pacific tree frog. It is most noticeable during the rainy season but remains active in a well-watered vegetable garden even in the summer. With its sticky toe pads, it is the only frog regularly found in trees and shrubs and on the north side of buildings.
How to attract these critters to your yard? They need shelter and food. Vegetable gardens can be a favored environment because they are usually damp and attract invertebrates that frogs prefer to eat. A frog shelter can be as simple as an upturned non-toxic terra cotta pot. In my winter vegetable garden, many cole plants, including cabbage, hold water at the base of their large outer leaves, which creates a safe hiding spot for the frogs during the day. At night, the cabbage plant is a perfect spot for a frog to feast on garden pests.
While I appreciate any frog living in my garden, the western toad (Anaxyrus boreas) is the most voracious. It hunts actively throughout the garden and is not intimidated by even the largest slugs. The western toad will swallow slugs whole and then carefully wipe the slime and dirt off its lips with its front legs. Such a neat and tidy guest. It also has a larger-than-life personality. If you find a toad’s daytime shelter in your garden, you can strike up a friendship by offering it some food (preferably a slug).
Another helpful group of amphibians is salamanders. Depending on the species, their diet includes small to large invertebrates such as sowbugs, cutworms and slugs. The California slender salamander (Batrachoseps attenuatus) and ensatina (Ensatina eschscholtzii) are both common in my garden, though salamanders are quite sensitive to human disturbance; lawn mowing, weeding, weed mats and pets have a negative impact on them, so it’s best to keep their natural history in mind when working in the garden. To support salamanders in your garden, provide semi-buried logs or a layer of leaves on top of the soil so they have cool, damp summer shelters.
The California slender salamander is easy to overlook because of its small size, tiny legs and slow-moving lifestyle, but be prepared for a shock if a coastal giant salamander (Dicamptodon tenebrosus) visits your garden. Reaching up to 13.4 inches long, it is the largest terrestrial salamander in North America. With its size and aggressive (for a salamander) behavior, its diet includes much larger prey, including small mammals (mice and voles, but not chihuahuas), snakes and fish.
The medium-sized ensatina defends itself with a whitish mucous toxin that it secretes from its tail. Its population seems to be stable throughout the Pacific Northwest, which makes the ensatina a useful bellwether of how environmentally friendly your garden is to wildlife in general. A native garden is more than butterflies and bees — let’s also make room for creatures with warts and slimy skin and nocturnal habits. Providing habitat for native amphibians is good for them and your garden.
Pete Haggard (he/him) and Jane Monroe (she/her) are coauthors of Rewilding: Native Gardening for the Pacific Northwest and North Coast, available from The Press at Cal Poly Humboldt.
This article appears in ‘If Only We’d Done More to Save Her’.