My hosta are getting eaten – there are lots of holes in the leaves …
I just planted four basil plants yesterday and this morning there are small holes in the leaves …
My lettuce leaves have lots of holes in them looking like something has been eating through them at night …
These are just a few of the inquiries we’ve gotten this season about plants (especially hosta) that have holes chewed in the leaves and recently we’ve been getting a lot more.
Most of the time, this damage is the result of snails and slugs snacking on the leaves of the plant during the night. Snails and slugs are slimy creatures that venture out under the cover of darkness and feed on the tender leaves and stems of many garden plants. Since they feed at night, they are usually not “caught in the act” like many of our other garden pests. They leave ragged holes in the foliage of our prized hosta and zinnias and can completely devour young seedlings in the vegetable garden in a matter of a few hours. These nasty pests secrete a slimy mucous which covers their soft bodies and as they move along over the plants, they leave silvery slime trails behind on the foliage as evidence of their feeding excursions. Hosta, Delphinium, petunias, zinnias, and leafy vegetables are some of their favorite foods.
Slugs and snails are normally active when the weather is cool and/or damp which usually means a peak of feeding activity (hence damage to our plants) during the spring and fall. Unfortunately this coincides with the time when we gardeners are trying to establish our vegetable and flower gardens. During the heat of the summer, they become less active; seeking out cool hiding places to hang out in until the weather becomes more to their liking.
One way to beat a slug and snail problem is to plant things that they don’t find palatable. Plants with thick, leathery or rough leaves, plants with hairy stems or foliage, and plants that exude a lot of sap when injured are generally avoided. Believe it or not, there are even some hosta that are passed over by these guys. Hosta with heavy substance or thick waxy leaves like ‘Love Pat’, ‘Paradigm’, ‘Sum and Substance’, and the sieboldiana and tokudama cultivars are usually left alone.
Unfortunately, many annuals and perennials that we plant are susceptible to snail and slug predation. For these plants, controls are often needed to prevent damage. Hand picking is one method of control for snails and slugs. It’s not too bad to remove snails because you can pick them up by their hard shells. Slugs are another matter, though. I, for one, just don’t have the “stomach” to pick up their slimy, muscular bodies. When I accidentally squeeze one that is hiding under the lip of a pot or a flat of plants, I just cringe. And then there’s the slime that takes a vigorous scrubbing with a brush to get off your hands … Ewwww, nasty!
Instead of going out at night with a flashlight, a better way to take care of picking slugs is to lay short boards on top of some low stones to create hiding places for them. In the middle of the day, turn over the board and use a stick or something to knock any slugs off into a bucket of soapy water.
Take that you slimy beasts!
There are also some all natural slug and snail control products available for use on ornamentals as well as in vegetable gardens and around fruit trees. Most of these are composed of pelletized iron phosphate and are safe to use around pets, wildlife, worms, and beneficial insects when used according to the label directions. They are easy to apply – just sprinkle on the ground around the plants according to the label directions. Some examples are Bonide Slug Magic and Bayer Advanced Natria Snail & Slug Killer Bait.
Click here for more information on slugs and snails
My hosta look terrible because of all the slug and snail damage. Should I do anything special to them now that fall is here?
This is a great question. At any time, you can prune off any yellowed leaves or damaged leaves to make the plants look better. At this time of the year, if your hosta (or other perennials) have become yellow and ragged looking, you can simply cut them back to the ground. Fertilize them now and again in the spring with Plant-tone or Holly-tone. They will come back beautifully in the spring.
Until next time – Happy Gardening!