Gardening corner--The White Snail invasion

Gardening corner—

Some of you may have noticed a rather severe infestation of snails last year (2005-6) after all the rain. Apparently we have a new snail in the neighborhood. The white snail, Theba pisana. Their shells come with a variety of markings. Some resemble the larger brown snail. Some have much lighter, whiter shells. All have a lighter flesh color than the brown snail and the tail of the white snail looks distinctly lighter when I put the two kinds next to each other and let them crawl.

The white snail has a different eating habit than the large brown snails and the small decollate snails (ones with the pointed very twisted shells). Our white snail friends climb into bushes and trees immediately upon hatching and have a voracious appetite. They especially like flowers, leaves of any thing in pea family (vetch, lupine, clover, broom), citrus trees and many other ornamentals that neither of the other two kinds of snails ever bothered. In my yard they are eating the leaves of the Catalina Island bush mallow (hibiscus family). A quick internet search turned up a statistic about finding several thousand in one citrus tree. Go to http://creatures.ifas.ufl.edu/misc/white_garden_snail.htm

Because they do not feed on the ground as much as the brown snails, they are difficult to kill with bait sprinkled here and there. They can be hand picked early in the morning or a liquid version of snail poison can be used to spray on leaves of the bushes and trees that they are eating.

Trees that are too tall to spray can be protected by a copper metal band around the trunk as long as no leaves or branches are touching the ground or other nearby foliage. Copper is poisonous to the snails and they will not cross it. (The problem is that as the tree grows the band must be continually readjusted or it will squeeze into the expanding tree, girding and then eventually killing it).

The state of California tried to control the white snail when an infestation was discovered in Oceanside in the late 80’s but had to give up. The snails reproduced too fast and money for containment wasn’t budgeted in sufficient amounts.

The snails have slowly spread from Oceanside and now they appear to be here in our neighborhood. It is up to the individual gardener to control the snails. It is a bit time consuming but so far I have found it possible to kill most of them (I think).

Topics for future columns—
--What happened to all the earthworms?
--What about those introduce exotic fire ants? Can they be stopped?
--How to keep the small black Argentine ants out of the house.
--Controlling and killing those annoying flies that constantly try to get into our eyes, noses and ears in the spring and summer when the weather warms.
--What is that grass that grows right through a thick cover of ice plant and whose top breaks off leaving the roots to re-grow.
--The worst weeds to have in the yard. The ones that maximum action needs to be used against the moment they are discovered in your yard.
--Why lawn herbicides are not the best bet for your health or the health of any mulch you make from the lawn clippings.
--Where to get extremely cheap mulch in abundant quantities.
--How to change our crummy white clay soil into top soil in a few hours of work.

On the home improvement front:
How can we get our heavy double, pane windows to glide open and shut at the touch of a finger tip.
What’s that moisture doing in between our double paned windows? Is there a fix?
What’s up with the low water pressure in our homes?
How do you know if you have termites? What is the most common scam of termite inspection business? How to get your money’s worth after having your home treated for termites.
Which local car repair and other businesses can be recommended by our Ahmu Terrace neighbors. Which ones are not recommended?
A common real estate scam that cost me big time. How it works and how to protect yourself when buying or selling property.