GROWING CONCERNS: With invasives, it's pot up or shut up

Several gardeners commented on the May 26 column, which discussed invasive plants. Most wanted to add to the list of disorderly flora. I also heard from Sallie Peterson, who declared, “I won’t give up sweet woodruff. My dog loves to roll in it and it makes him smell good!”

Hurray for your doggie, Sallie. He certainly has better taste in rolling material than mine. Invasive plants have their place, mainly in pots. But if they’re useful or beautiful, make the most of them.

Among the plants mentioned in the previous column were those that reproduce by seed: You know the ones; the seed package casually mentions that they “self sow readily.” Johnny jump-up, English daisy, feverfew, and other prolific producers may be controlled by deadheading, but snipping hundreds of miniscule blossoms can be tedious, at best. So if you can’t snip ‘em, pot ‘em; put them where the seed heads won’t drop into the lawn. Actually, English daisy is purposely included in eco-lawn seed, a mix of low-growing flower and grass seeds for those who would rather grow than mow.

Calendula is so perky and hardy that I feel guilty including it among invasive plants. But it IS an annual on fertility drugs. If you have one calendula this year, you’ll surely have one hundred next year. The same goes for California poppy. However, if you WANT to attract attention, what could be more eye-catching than a floral swath of neon orange fronting your home or business?

Artemesia “Limelight” is a perennial with luscious lime green and cream variegation. Unfortunately, it also makes lots of little Limelights that grow on thick, dandelion-like roots. But pot it with bronzey-pink potato vine or purple- and fuchsia-colored trailing petunias, and it will positively illuminate your patio or porch.

Another prolific spreader is Siberian iris. It can double, even triple in size each year. However, it produces elegant late spring flowers and graceful, grass-like leaves, which handily hide horizontal eyesores such as propane tanks.

Tent caterpillars revisited

During the past few weeks, the majority of calls for help to Island County Master Gardeners have been about tent caterpillars. If you see tent caterpillars outside the tent, they’re no longer feeding; they’re looking for a place to spin cocoons. At that point it’s too late to spray, but you certainly can squish as many as you can find to stop the cycle.

However, I learned for myself that not all tent caterpillars are pupating now, even though it’s beyond their normal season. While taking a sunset stroll around Flying Frog Gardens yesterday, we discovered young caterpillars still squirming in their tents, chowing down on a laurel hedge. We cut off the branch ends and dunked them, tents and all, into a bucket of water. Had their been too many to drown, we’d have reached for the BT (Bacillus thuringiensis), the environmentally safest spray for caterpillar control.

More and more evergreens are dying, even natives such as fir and salal. Learn what’s causing the destruction of these normally hardy Northwest icons in the June 23 column.

Mariana Graham is an Island County Master Gardener and member, Garden Writers Association. Garden problems may be directed to the Master Gardener Hotline Mondays from 10 a.m. to 2 p.m. at 240-5527.

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