Unless we use pesticides, our gardens are crawling with bugs! To have a beautiful and healthy garden, ornamental, edible or whatever, we have to encourage the good bugs that will help us get rid of the bad ones, that eat shrub leaves, put holes in our veggies, bring in plant diseases, and generally make a mess of our plants.
First we have to get to know who is who. So get yourself a small hand lens and start checking out the insects in your garden. You will hopefully see some of the following:
- Ladybugs are the poster girls of beneficial insects, because of their total cuteness! Who doesn't love them. The adults eat up to 50 aphids per day, and the larve – look for yellow and black alligators – eat up to 400 aphids before pupating. Ladybugs also eat other soft bodied insects, like mealybugs, and soft scales.
- Ground beetles are the shiny, dark coloured guys with the jointed legs, often found under plant debris or organic mulches. They work at night, devouring insect eggs and larva.
- Lacewings are those beautiful, gauzy green winged bugs that remind me of Tinkerbell. Their larva (1/2” tiny alligators ) eat voraciously of aphids, mealybugs, leafhoppers and whiteflies. You definitely want them in your garden as they are the most effective predator you can buy.
- Hoverflies are those little bee looking insects with the striped abdomens. But they buzz around like flies when they are laying their eggs near aphids or other soft bodied insects. The hoverfly eggs hatch and eat the aphids. Smart huh!
- Parasitic wasps are tiny, tiny, and non stinging. The best known are the Trichogramma. Parasitic wasps lay their eggs in moth and butterfly eggs, which could grow into those ugly loopers that eat your cole crops or build tents in your trees.
- After getting to know your bugs, you will wish to encourage more of the beneficials into your garden. To do this, you need to provide a diversified habitat of shrubs, perennials and annuals for nectar and protein, water, and shelter. Try to include plants that flower at different times.
Lets start with the annuals as they grow quickly to provide nectar and protein, and there is plenty of choice. Any plant with an umbel flower ie like a dill flower, is beloved by beneficials. This includes dill, Queen Anne's lace, and carrots and parsley if you let them go to seed.
Plants with composite flowers – think daisy here-, are also great. So include cosmos, zinnias, annual asters, marguerites, california poppies, Gem marigolds, sunflowers and bachelor buttons.
I plant a lot of allysum too, especially around roses, because allysum brings in a lot of aphid eating syrphid flies. It also is wonderfully fragrant, and makes a great edging or annual ground cover. Borage is another great annual for dry situations. Lacewings love to lay their eggs on borage, and it has true blue, flowers that taste like cucumbers, and are good in salads.
Include some perennials when you are shopping for annuals. Agastache has leaves that smell like licorice, and the pretty blue, fuzzy flower spikes are very attractive to a number of different beneficials. I recommend trying perennial asters, yarrow (try Moonshine, the designer's favourite), lavender, mint, goldenrod, red flowering thyme, and echinacea.
I'm experimenting with the red flowering thyme in my Brassica veggies this year. I'm hoping it will attract parasitic wasps to eat those looper eggs. Perennials with dense crowns and woody stems are great for shelter. Leave those stems over the winter for best results. Clump forming grasses are good for shelter too.
Last but not least, there are some good shrubs to include in your garden. Pussy willows provide early pollen. Forsythia, potentilla, ceanothus, euonymus, and pyracantha are all helpful for pollen and nectar, and to provide shelter.
Art's Nursery regularly has some benefical insects available, including ladybugs, predatory mites, nematodes for weevil control and nematodes for your lawn. Some may be a special order, so just ask the friendly staff. Other beneficial insects are available by mail order too.
So, it's certainly not a quick bug fix, but over time you can have a beautiful and chemical free garden and habitat for you, and all kinds of other creatures. Experiment and research to find what works best for you. It's fascinating!