Saving a Sluggish Spring Garden Without Using Poison
Here they come, up and over the fence, across the sidewalk and out from under old boards, pots and garden debris.
As the weather warms and nights become dewy, snails and slugs go on the prowl, looking for tender young seedlings, even crawling up into citrus to munch on flowers, leaving silvery tell-tale trails.
The common garden snail can patiently travel up to 100 feet a night in search of food.
Of all the new pests that have arrived in California--from fire ants to the giant whitefly--few are as destructive to gardens as snails, also an introduced pest (as are many slugs).
In the 1850s, a Frenchman brought snails to San Jose hoping that Californians might learn to eat them. Unfortunately, he brought the wrong species (according to “Tiny Game Hunting” by Hilary Klein and Adrian Wenner, Bantam Books, 1991), and soon the escaped escargot were eating California.
But have hope. In the last few years, several products and techniques have made fighting snails and slugs much easier and safer.
Baits
The newest is a product that you can use just like poison baits, only it is not a poison. Called Escar-Go!, it won’t poison pets, children, birds or other wildlife. And it is organic, made of naturally occurring iron phosphate combined with a bait that is attractive to slugs and snails.
It is said they prefer the bait over plants and once they eat it, they stop feeding and die within a few days, although you may not see their remains as you would with poison baits.
A few weeks ago I got a call from Sharon Milder, whose garden was on the cover of last year’s “Los Angeles Times California Gardening Calendar.” Her garden is a wonderful mix of perennials and old roses, but it has been plagued by snails and slugs.
She was calling to tell me that Escar-Go! worked. Milder had been handpicking about 30 slugs and snails a day and now she is finding almost none.
She bought hers from Gardens Alive, 5100 Schenley Place, Lawrenceburg, IN 47025, (812) 537-8650. It sells a 1 1/4-pound box (which treats 1,250 square feet) for $9.99.
The bait is meant to be scattered around the garden, not put in piles.
Predators
There are very few natural enemies of snails, with the exception of opossums and roof rats. Opossums can rid a garden of snails, given the chance.
At one point my garden was completely free of snails, thanks to an opossum. Unfortunately, it moved on.
The next-best predator is the decollate snail. This is a good time to release these carnivorous snails with their pointy shells into your garden. They will rarely nibble on tiny seedlings, feeding mostly on garden snails. They do not, however, eat slugs.
If you resort to decollate snails, you can’t use any kind of bait in the garden.
Decollate snails can be purchased at some nurseries. One mail-order source is Mary’s Decollate Snails, 912 Cassou Road, San Marcos, CA 92069-9233, (760) 744-9233. A cup of 100 costs $19.50 and treats about 200 square feet.
Slugs have even less in the way of predators, but there is one--those shiny black ground beetles found under garden litter. Cherish them.
Barriers
Solid lines of crushed eggshells, oyster shells and wood ashes have been used as barriers, and now the Los Angeles Cooperative Extension Common Ground Program has suggested a new barrier--liquidambar balls. A minefield of these spiky seed pods would certainly deter me!
The most effective barrier is a copper strip, especially one sold as Snail Barr, that has edge tabs that can be bent over at a 90-degree angle. You can even order Snail Barr in 100-foot rolls so you can wrap the copper around entire raised vegetable beds, totally excluding snails and slugs.
The pests do not like to crawl across copper because they apparently get a mild shock from a natural ground current. And that 90-degree bend is tricky to negotiate.
Last year, I stapled a roll around the raised beds in which I grow lettuce and have had nary a nibble since.
You can also wrap this barrier around the trunks of citrus to keep snails out of the trees. In both cases, however, make sure the protected plants do not touch the ground--or walls--beyond the barrier, or these pests will use limbs or leaves as living ladders into your beds or trees.
Copper barriers are available at some nurseries. Mary’s Decollate Snails also sells Snail Barr through the mail.
Traps
Many gardeners swear by beer for trapping and drowning snails in shallow dishes. My experience is that this doesn’t work as well as it’s cracked up to, at least in Southern California’s dry climate, where liquids quickly dry.
Trapping slugs and snails under old boards is surprisingly effective, because both will hide under boards during the day if they can.
Use a couple of 2-inch-wide strips of wood as runners on either side of a piece of 1 by 12 board, so the bigger board is kept off the ground. Set it near places where snails and slugs are active and check it every day. You’ll find lots hiding on the underside.
Squish them with a stick. The smashed remains are actually likely to attract even more the next night. Or scrape them into a plastic bag and put it in the garbage.
Snails are likely to be found in the garden around or in agapanthus, iris, ice plant, ivy, jasmine and nasturtium.
Perhaps none of these strategies will completely eliminate these mollusks, but a combination of techniques should bring prompt relief and help your garden survive another spring. And with no poisons.
In the Garden is published Thursdays. Write to Robert Smaus, SoCal Living, Los Angeles Times, Times Mirror Square, Los Angeles, CA 90053; fax to (213) 237-4712; or e-mail to robert.smaus@latimes.com.
