Two of my Statesman podmates — Dana Oland and Katherine Jones — were commiserating recently about battling bugs on their yard and garden plants. So I took notes.
Nothing really new, they said, just those pesky aphids.
I’ve either been really lucky, or not observant enough to notice aphids on my plants (probably the latter). They leave a cruddy, sticky film on plant leaves.
They’re not always a problem requiring intervention but an infestation can literally suck the life out of plants, said master gardener Debbie Courson Smith.
“If the aphid load becomes too great, the plant can die. Aphids spread disease, too,” she said.
Aphids reproduce rapidly in an asexual process called parthenogenesis, with one bug capable of producing billions of offspring in a single season.
Debbie said she once used a systemic pesticide to control aphids on her plants.
“It worked, but the systemics can also harm beneficial insects,” she said. “I don’t think it’s a good idea to eat plants treated with systemics (check the pesticide label), and since I enjoy making candied rose petals, I stopped using chemicals.”
Her recommended method of aphid removal will cost you time, not money.
“I blast them with the hose,” she said.
In this week’s Dig In video, Debbie demonstrates how some gardeners slip on plastic gloves and wipe the bugs off plants.
The garden hose “blast” method definitely looks more fun, though you obviously have to be careful about not turning the stream up so high that it knocks the blooms off your plants. A nonchemical method of removing aphids from plants will also mean you’re not inadvertently killing the beneficial bugs.
But a lot of gardeners, including Dana and Katherine, talk about killing aphids by spraying soapy concoctions on them. Dana said she has had good luck with an insecticidal soap she bought from Edwards Greenhouse in Boise.
I stopped off at North End Organic Nursery to see what they recommended for aphids — and walked out with a bag of 1,500 live ladybugs. Ladybugs and their larvae feast on aphids, so they can be a natural control.
But University of California researchers say that ladybugs must be handled and applied properly to be effective.
In an article on the UC Division of Agriculture and Natural Resources’ Green Blog online, researchers advise keeping ladybugs refrigerated until they are released — and that should be done in the evening or morning, when it is cool and dark. Applying water to plants before releasing the ladybugs is also advised because they’re likely to stick around longer (that’s important since it’s their larvae that eat the most aphids).
The California researchers advise two applications of 1,500 ladybugs about a week apart to treat one large, heavily infested rose bush. The package of ladybugs I bought at North End Organic Nursery was $8.29.
But again, the hose works too.