Ask the gardening expert
Thursday, February 21, 2013
Our family moved here last year from Arizona. I had never gardened before and am so happy to be able to, but I'm just dismayed at slugs in my flower garden — and even in my vegetables. I never expected that.
Yucky slugs — where do they come from? What can I do about them?
Arizona, being hot, dry gravelly sandy soil for the most part, surely does not sound like slug terrain to me. Slugs must have been a rude surprise. In the Pacific Northwest, we have been dealing with them forever, and I guess we take them in stride -- which is not to say we like them.
They are an important part of our ecosystem, doing good work as part of nature's cleanup crew, and we benefit from their work in the forests — but we take great exception to the fact that they also want to devour the plants we value.
There are many species of these critters. A few we often see:
• The common brown garden slug was originally a European species, Cornu aspersum, and is now established in many areas of North America.
• Annoying and easy to overlook, the Oxyloma species are the little light-colored guys that hide in containers and at the base of plants. You might find 8 or more in a container that you planted, having come in with the soil or nursery plants.
• Our native banana slug, Ariolimax columbianus, as a rule does not deserve abusive words. They are (by our standards) hard workers that stay in the forests, do the cleanup work mother nature assigned them, and seldom stray.
Slugs and snails are members of the phylum of mollusks, like octopi and oysters. Their taxonomic class is called gastropoda — "stomach-foot."
Depending on the species, these animals are well adapted to devouring a range of foodstuffs, including living and dead plants, fungi, small dead animals, and sometimes live prey; this may occasionally include each other.
Early detection is key in pest management. Be diligent; never stop looking!
Since they are night feeders, after-dark flashlight hunts are effective. Look under containers, the edge of pots, under boards, piles of weeds, and debris. Some people leave a board lying on the ground to attract the slugs for more convenient picking. You can crush them, seal them in a plastic bag for the trash, or drop them in a pail of soapy water until they're dead, then pour it on the compost pile.
Some folks have success with homemade slug traps baited with beer, some people use wood ashes, and others use diatomaceous earth (which needs to be reapplied after it rains or you water the area with a sprinkler).
There are chemical granules, which also need to be reapplied after rain. Some are dangerous to pets and curious children. Slug pellets made of iron phosphate, a natural component of soil, are said to be harmless to pets and humans; Sluggo is a popular brand available in garden centers. Slugs are attracted to it, eat it and die.
From what I've read, copper strips are a real deterrent. They may be somewhat expensive but work as long as they stay in place.
That being said, nothing works as well as your own determination, and diligence to keep after them.
I've heard there are new developments in growing tomatoes. I know the catalogs mention all kinds of methods, types, colors and varieties for various culinary uses. It sounds so specialized! How is a person to sort through all the information and get just some nice tomatoes?
You're right, it's a lot to sift through. In nearly all agricultural and horticultural fields, there is great research and development of new cultivars and varieties — it seems there are new plants on the market for every trait you could desire.
A new (to me — apparently it's been around in other regions for a while) method being talked about is grafted vegetable plants, with the desired variety grown on sturdy rootstock from a different variety.
My attention was caught several years ago by the "greenhouse tomatoes" Territorial Seed Company talks about. Varieties that are parthenocarpic — forming fruit without pollination — offer several advantages. You can grow them in a greenhouse, for one, to lengthen your season. Even outdoors, they can set fruit before it's warm enough for bees to be out on the job of collecting pollen, and give you ripe tomatoes several weeks before other types.
Another thing I appreciate is when a catalog states for each variety whether the plant is determinate (forming a bush) or indeterminate (sprawling all over as a vine). It's important to know ahead of time the spacing and trellising you'll need for each plant you put in.
I noticed a landscape crew cutting an ornamental grass bed plus some evergreen shrubs. Is February too early to do such chores here? Should I cut my ornamental grass now in early February?
I think most grasses could be cut here in late February to early March.
The chances of a hard winter event get more remote as the late winter days go by -- I expect we can see some wet snowy days here and there yet, but it's getting late for the real plant-killers. The trouble comes when the plants are dry in the ground and then we have a period of hard ground freeze.
As for your own ornamental grasses, if you see new growth deep in the plant, it's getting going, so you might cut off last year's growth soon. In the higher areas of the county, though, you might wait a few weeks.
Celeste Lindsay is a WSU-certified master gardener. Send questions to email@example.com.