If you're a gardener, you know that few things are more discouraging than seeing your tomato vines taken over by a virus, your broccoli enveloped by aphids, or a squirrel digging up your newly planted garlic bulbs. While gardening requires a certain amount of zen and flexibility when dealing with all the “what ifs,” there’s a lot you can do to mitigate troubles beforehand. Rotation-plant the crops in order to avoid viruses and fungi; plant garlic under hardware mesh—and believe it not, battle pests like aphids with other insects. Yes, that’s right: You can create your own insect Thunderdome, right in your garden.
How insects can help a garden
As with all aspects of the animal kingdom, there is a pecking order, and most insects have natural predators as well as intended victims. For instance, earthworms consume nematodes, and then get eaten themselves by bluebirds (really, all kinds of birds, but I enjoy watching the scrub jays really go at it in my yard). We tolerate spiders because they take out the flies, and then those spiders get taken down by amphibians. When your garden is out of balance, you can introduce beneficial insects to even the odds again, and in the process, you can avoid chemicals you might otherwise use to do the same.
Ladybugs aren't actually a great choice
The first introduction most people have to this beneficial bug practice is those packages of ladybugs at the big box store, which promise to dispose of aphids. If you’ve tried this unsuccessfully, that tracks, because you were duped. Ladybugs aren't grown in a lab—they're harvested in the wild, and this is considered problematic by environmentalists. The harvesting has caused the population to drop enough that the invasive Asian lady beetle, an entirely different bug, has been able to establish itself. In fact, you may be getting Asian lady beetles in your ladybug batch. Also, wild-caught ladybugs can introduce parasites to your garden.
Putting all that aside, ladybugs only hang around in specific conditions, which usually aren’t met by those deploying them in gardens (if they were, you’d get tons of ladybugs naturally). Ladybugs love aphids, but not all aphids. I was surprised many years ago to learn, for instance, that they don’t feed on lupine aphids. Also, you have to deploy the bugs at twilight, and they prefer moisture. Lastly, ladybugs are migratory, so they’re not interested in putting down roots in your yard. They’re going to grab a small aphid snack and then GTFO. In short, don’t buy them.
Before you buy, you need to know about your yard
If you have the right conditions in your yard, you will create an environment that invites beneficial insects and a balanced ecosystem. A bathouse invites bats; certain bird shelters will invite swallows. Water features will invite frogs and other amphibians, and if you do it all right, you might end up with an opossum or two. These animals will help keep snails, slugs, aphids, rodents and other pests in check. You can also choose non-toxic methods like sticky traps and tape before you deploy anything live in your yard.
If those methods aren’t possible or you still need a kickstart, you’ll need to complete a few steps before you purchase some beneficial insects. The first is, what kinds of pests are you having issue with, specifically? This is critical because it determines what kind of beneficials to purchase. You also need to know your current climate. What is the temperature during the day and night? This is critical for deployment. You also need an assessment of how bad the problem is.
Some tools to help encourage a balanced ecosystem in your yard:
Cedar bat house: $100.95
Garden water feature: $95.99
Green lacewings, assassin bugs and minute pirate bugs
Most of us suffer from soft-bodied pests like aphids, and beneficials like green lacewings, assassin bugs or minute pirate bugs can help address them. Which you choose will depend on the questions above—minute bugs are fast-acting, but assassin bugs are more heat tolerant. Lacewings are a gentler way to handle pests, but aren’t for severe infestations. How you deploy the insects is going to depend on where the pests actually are—whether you release them into the soil or onto plants.
Nematodes
Nematodes are another beneficial you might have heard of. These microscopic organisms can help manage pests that live in the soil or have pupal stages—so they can get rid of all kinds of moths, weevils, cutworms, maggots and borers, even thrips and termites. There are different types of nematodes, so you’ll need to know more about your specific kind of pest.
Praying mantis
If you’ve seen gardeners going all gooey over finding praying mantids in their garden, there’s a reason. These delightful characters are amazing at pest control in a garden, and you can actually purchase them in their egg case, called an ootheca, to introduce them to your garden. Like all others mentioned above, these bugs are very specific about conditions: They like 60 degree and up temperatures.
To buy these bugs, you want to skip the big box stores and go to a specialist like Arbico or Sound Horticulture. Customer support will help you figure out what kind of bugs to use, how many, where and when.