The Cupertino Courier

Gardening

Simply Blue: Cornflower, also called bachelor's button, is an easy-to-grow annual best known for its lacy blue flowers, but other floral colors exist. Cornflowers prefer full sun exposure and moderate irrigation.

Warning: Cigarettes can be hazardous to aphid's health

By Tony Tomeo

The main advantage of getting so many telephone calls and emails about gardening issues is that I get to hear about what other people are doing to solve problems in their gardens. Then, anyone else who later inquires about the same problems thinks I am so very knowledgeable because I happen to know of a possible solution. In my own garden, problems typically arise after their solutions have already been received.

For example, I have often been told that a bit of Tabasco sauce in a solution of very mildly soapy water will both kill certain insects and discourage their return for a couple of weeks. Although practical only for small applications where it will not be rinsed off, such as houseplants and potted plants, this concoction can be effective against aphid, mealybug, whitefly, thrip and mite infestation. (Mites are actually arachnids, not insects.) The soap alone will kill aphid, and really annoys thrips and mites. The chemical that makes peppers "hot," capsaicin, kills some of the other insects, and really offends those that survive.

Squirrels do not like capsaicin, either. In the hardware store, I noticed ground chili pepper is the active ingredient of a product that is mixed with birdseed to keep squirrels from tampering with birdfeeders. There are no birdfeeders in my garden, but squirrels had been digging in my flats of seedlings. I just happened to have a large, cheap can of chili powder, so tried sprinkling some of it out over the seedlings. The squirrels have not been a problem since. Unfortunately, I do not know how to water the flats without washing the powder away, or if the absence of squirrels is actually a direct result of the powder application.

Another slick trick I heard about is the use of cigarette butts and filters as an aphid repellant for small plants. Fortunately for both people and insects, cigarette butts are not quite the commodity they used to be. Those of us who happen to have a source can simply place them on the soil near the base of the plants. No one seems to know why this works, but many believe the aroma is as offensive to the aphid as it is to some of us, which is why it does not work for larger plants with foliage suspended farther from the ground. Although nicotine is toxic to insects, plants probably do not absorb it as a systemic.

The drawbacks to this procedure is that it can smell bad up close, and no one really wants all the cigarette butts strewn about their potted plants. My attempt was actually unsuccessful for my potted impatiens, and the ash made a mucky gray mess. I would suggest separating the butts from the ash instead of simply dumping the contents of the ashtray. Too much ash can contribute to soil alkalinity anyway. My second attempt with tobacco from cigar butts seemed to be successful, but the slightly rotten aroma that developed after a few days was as bothersome as the aphid.

The unpleasant aroma of fish emulsion fortunately dissipates within a day. This may disappoint neighborhood cats, but not the plants that are grateful for this very basic fertilizer. It works as quickly as soluble fertilizers (applied in solutions) but, unlike soluble fertilizers, does not cause salt burn, even if a bit too much is used, or if it is applied a bit too often.

The Smart Gardening Faire on June 24 will be an excellent source of even more gardening wisdom. Open from 9 a.m. to 5 p.m. in the Scotts Valley Skypark, the Smart Gardening Faire will feature demonstrations by local gardening groups, children's activities, horticultural lectures and a marketplace of gardening accouterments, plants, books and art. There will be live music and healthful food vendors. Admission is free. For more information, call 831.457.7272 or visit www.smartgardening.org.

Flower of the Week:
cornflower

Those who like blue in the garden should be familiar with cornflower, or bachelor's button, Centaurea cyanus. It is most popular for its clear blue, 1 ¹/2-inch- wide flowers, which incidentally can also bloom in white, pink, rose red or burgundy red. The narrow plants are about a foot tall, with thin, 2-inch-long, silvery green leaves. Plants grown from seed sown in early spring should bloom by the end of spring for a month or two.

Horticulturist Tony Tomeo can be contacted at 408.358.2574 or at LGHORTICULTURE@aol.com.