4/1/2018
How to Bug a Gardener
John Friel
As the public increasingly embraces the idea that beautiful gardens needn’t be chemically dependent, the industry has responded admirably with natural solutions. Growers and gardeners alike have numerous safer alternatives to jugs emblazoned with skull and crossbones logos.
Even formerly spray-happy gardeners have accepted that all insects are not created equal—that good bugs should be actively encouraged, even introduced to fight bad bugs. That’s what Alison Kutz of Sound Horticulture and Cascade Cuts, Bellingham, Washington, has preached since 1981.
“We were definitely the first commercial nursery in North America to utilize compost teas in day-to-day production,” she says. “I’ve used beneficial insects since the beginning. I’m just a weirdo!” Weirdo? That was then.
I asked Alison for comments and recommendations: What’s best for home gardeners? Sound Horticulture’s website lists over a dozen beneficial insects. This Space can’t accommodate them all, so we’ll review some common ones. All quotes are Alison’s.
Praying Mantis
“We love them and find them fascinating. We will sell them or donate them for educational projects, but don’t push them hard.” They ARE fascinating, but natural? Not exactly. Most aren’t from around here; naturalized Asian species are more widespread than natives. This equal-opportunity omnivore kills and eats whatever its spiny forelegs can grasp: siblings, good bugs, bad bugs, even hummingbirds. It’s April, but I’m not fooling.
Lacewings
These are sold as eggs, larvae and adults. “We let the flying adult use her wisdom to seek out the food resource (like young caterpillars and aphids) and dump her stash of eggs right there! They’re amazing.”
Trichogramma Wasps
“Great for the homeowner—the most used beneficial insect worldwide. The eggs arrive on little cards to hang in the foliage. These can really help veggie gardeners with a variety of caterpillars, especially in broccoli, cabbage or cauliflower.”
But not all caterpillars are the enemy. There are those that destroy vegetables and then there are five larval instar stages of Danaus plexippus, the beloved Monarch butterfly. No caterpillars, no Monarchs. Just plant that asclepias where the inevitable damage is hidden.
Soil Nematodes
“Homeowners can and should use beneficial nematodes for soil-dwelling pests—grubs, cranefly, Japanese beetle or flea larvae in their lawn or local dog park. The trick is getting high-quality FRESH material. Perishability challenges affecting viability are the greatest difficulty facing the homeowner market. Garden center customers complain ‘they tried that and it didn't work.’ Well, nematodes DO work, fantastically.”
Ladybugs
Each spring, my prized lonicera would emerge from dormancy, green up and blanket my lamp post in flowers, only to be ravaged by aphids. I’d retaliate with chemical warfare.
One year, the aphids got ahead of me. But after a week of ugliness, the plant was once again lush, full and blooming copiously anyway. Why? Ladybugs, hundreds of them, devouring aphids. I never sprayed that plant again.
You can buy a bunch to scatter around, but Alison calls that “a poor idea. They do work, so they’ve become emblematic; but they’re scooped up in the Sierra Nevada mountains by companies with permits to do so (because) they’re difficult to rear in captivity. Shipped around the U.S., they can displace wild populations (and) have been known to transmit viruses.”
Other options include parasitoid wasps for mealybug and predatory mites for spider mites and aphids.
“In a nutshell, the topic of ‘Biological Controls’ is broadening each day, when we include emerging products (fungal, bacterial) that work well with the predator insects themselves.”
Couldn’t have said it better myself, so let’s stop there. GP
John Friel is marketing manager for Emerald Coast Growers and a freelance writer.