We know now that not all insects are harmful to your garden plants. In fact, a number of them are actually good to have around. A number of insects like lady bugs and praying mantis can help control the population of actual garden pests like aphids and caterpillars. But the trick is to encourage these beneficial insects to come and stay in your garden. You need to provide an environment where they can survive. 

The term we are looking for is "garden insectary". This is a kind of gardening where you place companion plants that can attract natural predators, and provide them with a habitat, and an alternative food source. Even though insect predators eat other bugs, they still need pollen and nectar in their diet. This is why you need to add plants that will give them just that.

A garden insectary is a small garden plot of usually small flowering plants which are attracts the beneficial insects. A garden insectary can occupy just a small space in your garden.

It would be ideal if you could plant six to seven varieties of flowering plants to attract different kinds of beneficial insects. Aside from variety, plants of different heights are good for your insectary. Different insects prefer different kinds of plants as their homes, the ground beetle, for example, often needs the cover from low-growing plants such as thyme, rosemary, or mint. Also a good suggestion would be to include both annual and perennial flowers, as well as the native varieties of plants, or shrubs or even trees.

Moreover, it is also often suggested that you put tiny flower producing plants in your garden insectary instead of big blooming ones. Some insects, like the parasitoid wasps, are so small that the large, nectar filled flowers can literally drown them.

When choosing plants for the insectary, it is also good that you first familiarize yourself with the different beneficial and pest insects. Recognizing which is which would help you identify which plants to put in your garden. Some of the best plants include:

The Yarrow. This is a flowering plant that has flat flowerheads and lacy leaves. It is great for attracting hoverflies, ladybugs and parasitic wasps. The only problem is, if left unmonitored, yarrow can easily grow all over your garden choking your other plants. The trick is to plant the yarrow in containers to avoid it growing all over the place.

The Shasta daisy. It is as perennial plant that has the daisy appearance, white petals around a yellow disc. Pirate bugs and beneficial mites seem to be attracted to the flowers. And pirate bugs are good hunters for thrips, aphids, mites, scales, and whiteflies.

Herbs like coriander, dill and fennel are good plants to attract the good guys, more specifically the hoverflies, lacewings, ladybugs and tachnid flies.

Lemon balm is another perennial herb belonging the mint family. The flowers attract bees, but also attracts parasitic wasps, and tachinid flies which are good for controlling outbreaks of whiteflies, moths, and fly larvae

Other plants that are good to have around include sunflowers, Scabiosa or the pincushion flower, Limonium latifolium of Statice, Daucus Carota or Queen Anne's lace, Tanacetum vulgare of Tansy, Foeniculum vulgare or fennel, Achillea filipendulina, Amaranthus, Convolvulus minor, Helianthus annulus, and Iberis umbellata.