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Marge Says, "Plant an Insectary!"

Allen's Cat MargeThe number one question I receive is not about gardening, but my cat Marge.  Everyone wants to know how Marge is doing.  I happy to report that she is holding down the fort at the house.  Right now she is probably stretched out on the loggia with one eye closed and the other open just enough to keep track of the goings on.  Bug activity is of particular interest to her and she has become quite the expert on insects that are helpful in the garden.

In today's column she has some advice for attracting beneficial insects to the garden including how to plant an insectary.

As much as I love Allen, it is often with relief that I watch him walk out of the garden, close the gate behind him and drive away in his car.  The man never sits still, which means I never sit still.  Keeping up with Allen Smith sure takes a lot out of a girl. 

I decided that if he had a little extra assistance in the garden he might be able to slow down a little so I've encouraged him to start a garden for beneficial insects; bugs that lend a helping hand.  Allen likes to call it the insectary, which is just a fancy term for an area dedicated to growing plants these bugs love.  He does enjoy his big words. 

Pollination InsectThere are three kinds of beneficial insects and they are classified by their “lifestyle” so to speak – predators, parasitoids and pollinators.  Predators eat other insects while parasitoids use pest insects as hosts for their eggs and larvae.  The pollinators facilitate pollination so plants can produce fruits and vegetables. 

An insectary will provide food and habitat for all three types of beneficials.  Even the predatory insects will find nourishment.  Don't be intimidated by Allen's big word, planting an insectary is simple.

First, choose a sunny spot in the garden.  Allen created a 3 foot x 12 foot strip at the back of the vegetable garden.  You can modify the size to suit your space.  You can plant several small insectaries around the garden or these plants will grow in containers, too.   Site the plants close to vegetable gardens, roses or other plants that will benefit from the insect helpers.

As with any garden, the secret to success is the soil.  Remove existing sod and vegetation.  Turn the soil to a depth of 18-inches and add amendments such as compost, sand and organic fertilizers as needed.  Rake the soil to make a smooth surface.    

Once the bed is ready you can sow seeds, plant seedlings or potted plants.  When it comes to plant selection choose both flowering and foliage plants so the area will be inviting from spring through fall.  Provide plants of varying heights, the short plants offer cover and the taller ones will be visible and attractive to the insects from a distance.  I was surprised to learn that bugs have a flower preference. They are especially fond of umbel-shaped blooms such as Queen Anne's Lace and dill along with composite shaped blooms  and such as zinnias or sunflowers.

Treat your insectary as you would any newly planted garden, but avoid pesticides and only use organic fertilizer. Give the plants consistent moisture.

Allen Working in the InsectaryBe patient.  Even though a colony of aphids, cutworms or mealy bugs often seem to appear overnight, it takes time to build up an army of beneficial insects.  It's important to get ahead of the curve by starting your insectary in spring.  To further speed the process along you can order beneficials from companies such as Gardens Alive or  Handle and release them according to the directions provided by the source.

Whether you plant an acre-sized insectary or just a few containers, creating a welcoming habitat for beneficials is just good sense.  As I told Allen, once you get the garden in place Mother Nature will handle the rest.  I'd like to say that the additional help has given him time to relax, but it just freed him up to do other things.  I guess a cat's work is never done.  


Beneficial Helps Combat Plants They Like
Lacewings Aphids Cilantro, Cosmos, Dandelion, Dill, Fennel, Queen Anne's Lace, Tansy, Yarrow
Ladybugs Aphids Ajuga, Buckwheat, Butterfly Weed, Cilantro, Dandelion, Dill, Fennel, Marigold, Queen Anne's Lace, Veronica, Yarrow
Hoverflies Aphids, Mealy Bugs Ajuga, Alyssum, Feverfew, Cilantro, Cosmos, Buckwheat, Lavender, Lobelia, Lemon Balm, Mint, Parsley, Sedum, Marigold, Thyme, Veronica, Zinnia
Parasitic Wasps Moths, Flies, White Flies Yarrow, Dill, Cilantro, Cosmos, Queen Anne's Lace, Fennel, Statice, Lobelia, Lemon Balm, Parsley, Sedum, Marigold, Thyme, Zinnia
Tachinid Flies Cabbage Lopper, Cutworms, Squash Bug Nymphs Buckwheat, Lemon Balm, Parsley


Recommended Reading

(And listening! This book includes a disk of insect sounds.)