Permaculture is a system of agriCULTURE that is PERManent. It is a perennial polyculture of plantings and it's designed to be low-maintenance and food producing. This spring we are gearing up to convert a small swath of property alongside the annuals growing area to an edible forest garden using permaculture principles. While we are busy seeding away for ourselves and our plant sales, part of what I'm trying to plan for is a wide range of flowering plants that will attract beneficial insects. The trick is to have enough flowering plants from spring through late fall to ensure the presence of these welcome bugs. These are called "nectary plants" by Permies.
There are 2 types of beneficial insects. Predatory insects catch and eat pests. Common examples are ladybugs and hover fly larvae. They have an insatiable appetite for aphids. By the way, our county's famous "suburban forager" Paul Tappenden tells me he quite likes the taste of aphids and thinks they have a walnut quality about them. Hmmm. I'll pass. The other type are parasitoid insects which lay their eggs on or inside the eggs, larvae, or adults of the pest in question. When the parasitoid eggs hatch, they devour the pest. A common example, if you re familiar growing tomatoes, is the tomato hornworm. In our first year of growing, I uncovered this horrific looking bug while pruning tomatoes. It was covered with what looked like grains of rice. I screamed and ran far away figuring the ick factor would be lessened by distance. Trying to solve the mystery, I googled "green caterpillar with rice" and voila! I found out that this was a GOOD thing for the garden. Those rice grains hatch to become baby braconid wasps that devour the host and fly on to find the next hornworm. What did we do before the internet?
So the trick is to plan out a place to attract these good bugs by planting nectary plants. One of the best types of nectary plants are in the Apiaceae family, previously known as the Umbelliferae family because their flowers produced umbrellas of tiny flowers. You know this family well: dill, carrots, celery, chervil, cilantro, fennel, parsley, parsnip and angelica. So when you don't get to eating your herbs or veggies before they flower, don't pull them - leave them in the garden to attract these beneficials! They are goreous as well.
This is the list of perennials (and some annuals) we're growing specifically for their nectary properties.
A great introduction to Permaculture and its principles and for more information on beneficial insectaries read Gaia's Garden, Second Edition: A Guide To Home-Scale Permaculture