An Insectary is an area of plantings which attract natural predators to your garden. Although this may seem counter to your thinking, allowing “Good” bugs to fight the “Bad” bugs is the way nature intended. Insects are our pollinators and by providing habitat, shelter and alternative food sources you can attract these beneficial insects to your garden. They can then do battle with those pests you do not want in the garden, aphids, scale, thrips, whitefly, mites , even grubs and slugs.
Aphid predators such as lady beetles need the pests to be present in order to reproduce, since their larvae are even more ferocious than they are. These pests will remain on the desired plant in your mini insectary yet provide an ideal breeding ground for the associated predators and parasites. Although Lady bug beetles may be purchased through the mail, once released they seldom stay in the garden unless you have an unusually large number of aphids to eat. Most gardens have some lady bugs to start with if you haven’t been eliminating them in your quest to eradicate the problem pests.
To establish an Insectary plant a “weed patch” somewhere in an out of the way place or add selective plants into your already established gardens. Either way will be a benefit to your garden and can eliminate pesticide usage. The plot does not have to be large, just big enough to hold 6-7 varieties of plants which attract insects, ours is on the site of our former compost pile and contains Feverfew, Garlic, Echinacea, Fennel, Tansy, Fleabane, Mullein, Chamomile and Yarrow. Now that it is full bloom, the blooms are covered with beneficial and predatory insects, ready to go to battle in the garden. This is not a quick fix and does require some patience but is a healthy way to garden.
In very simple terms, insectary plants are those plants which attract beneficial insects. Beneficial insectary plants are intentionally planted in a garden to increase the pollen and nectar resources which are required by “Good” bugs which are the enemy of “Bad Bugs”. In addition the Good bugs assist in pollination while “eating” in the garden.
“Good” bugs include ladybeetles, ground beetles, hoverflies parasitic wasps and bees. In addition, lizards, spiders, toads, insect eating birds and even hummingbirds are beneficial in your garden. Beneficial insects can be up to 10 times more plentiful when you have an insectary planting on your property. Many of these plants can be interspersed among your existing plants; many probably already are in your garden today. The insects which visit will help other nearby plantings too.
Although many of these plants are considered weeds; Queen Annes’ Lace, and Wild carrot, a majority are herbs which we desire in the garden. Fennel, Lovage, Angelica, Cilantro, Dill, and Parsley are some of the most common and they are also used as host plants for caterpillars. These plants bloom with an Umbel shaped bloom, many tiny blooms, attract a diverse group of parasitic wasps. Clover, wild yarrow and even rue also attract predatory insects (those that hunt down their prey). Creeping plants such as Thyme, Chamomile and low growing mints, provide shelter for beneficial as well as ground beetles. Composite flowers, daisy like blooms, Tansy, Feverfew, Echinacea flowers are great for pollinators and will also attract predatory wasps, hoverflies and robber flies and mints. Parasitic wasps will attack caterpillars and grubs to feed t heir young while predatory and parasitic flies will feed on leaf hoppers and other Bad bugs.
I realize some of you are now shaking your head. I suggest you plant host plants to attract caterpillars, now I suggest planting plants which will attract a wasp which may eat the caterpillars. Yes, I am, there is a happy median. If every caterpillar made it to an adult butterfly there would never be enough nectar for them anyway. By allowing nature to keep things in check you may lose a few butterflies but you will have a healthier ecosystem in our gardens. Since none of us can control things on a planet scale, let’s start one yard at a time.