NEWBERG, Oregon—In an earlier issue, I mentioned my trouble with mice eating my herb seed in the greenhouse, and I thought I’d bring you up to date on my progress. By chance, I discovered the fatal attraction, the final solution—filbert nuts. I had been complaining to my friend Joan about finding filbert shells brought in from the orchard and scattered under flats and between rows of potted herbs throughout the greenhouse. They were evidence that my cheese-baited traps weren’t working. She suggested that since filberts seemed to be the preference of our local mice, why not use the nutmeats as bait? I had tried so many other tactics that I was desperate. One day after baiting a trap with the nuts, I caught a mouse! For the next three weeks, I averaged one to three mice a day. I had had no idea that my mouse problem was that bad. Perhaps I was just luring them into the greenhouse with this new menu item.
It makes sense to use filberts as bait because the oils in the nutmeat last longer than cheese, but I am sorry that the traps also attracted a few hungry shrews, which pose no harm to my herbs and eat insects in the bargain. One day, a shrew no bigger than my thumb even came out from under a pot and nosed around my shoe.
Having dealt with my mouse problem, I cannot say enough about vigilance in greenhouse sanitation, especially constant weeding under the benches. I eliminate a lot of potential pest invasions by removing susceptible host plants of aphids, spider mites, and whitefly and possible winter homes for slugs. Sometimes I even recover the odd herb seedling that has sown itself under the bench from the stock plants above.
On the other hand, I intentionally use certain host plants to trap insect pests. I find that Nicotiana sylvestris and N. rustica, both members of the tobacco family and loaded with nicotine (a poisonous alkaloid), serve as particularly deadly attractants for aphids and fungus gnats. I situate them in pots strategically around the greenhouse.
In the herb garden, cardoon (Cynara cardunculus) is a good trap plant for black aphids. I would rather that the aphids congregated on it than my precious basil plants. There is nothing more satisfying on a hot summer night than a plump, sun-ripened tomato, sliced and topped with minced basil leaves in a dressing of oil and vinegar.
I’m very pleased with a couple of new acquisitions. Many people know of the caraway-scented thyme (Thymus herba-barona) with its wonderful fragrance, but a delightful lemon-scented version adds rich lemon overtones to the main caraway scent and is equally prostrate, a fast-growing ground cover smothered with dark pink flowers for weeks in the summer. Another recent purchase is sorrel geranium (Pelargonium acetosum), which although listed among the scented geraniums has no foliage scent and by all appearances looks like some strange succulent plant with rather large salmon flowers. Its name comes from its edible foliage that tastes like French sorrel and is used in salads.
At this time of year, I like to take advantage of the cooler temperatures in the evening to go for a relaxing stroll through the garden just before dusk. That’s when I can understand the attraction of designing a garden to be viewed by the light of the moon, which brings out wonderful silver tones and delicate hues often obliterated by stronger, harsher sunlight. Such silver-leaved plants as the artemisias, rues, and santolinas are often at their best in half-light. Perhaps I should get some white or silver pajamas for my moonlight strolls.