In a garden, a pest is a bug that feeds on or transmits disease to desired plants, whereas beneficial insects maintain the ecosystem balance by consuming these pests. A diverse garden includes a whole host of insects! Some act as pests, but by encouraging beneficial insects, you can be sure that the overall balance means fewer pests and diseases will take hold.
Roles & Types of Beneficial Insects
Pollinators (Lacewings, Mason Bees, Hoverflies): Not only do many bees, butterflies, and flies pollinate plants, but many species also eat or destroy “bad bugs” in the landscape during their larval stage.
Predators (Lacewings, Ladybugs, Nematodes, Praying Mantises): Some insects are predaceous in their larval stage, while others predate insects as adults. Some predatory bugs have a diverse diet, while others specialize, eating only one type of food source.
Decomposers (Earthworms, Hoverflies): Both in the larval stage or as adults, many beneficial bugs live in the soil, eating leaf litter and other dead parts of plants or dead insects. By eating dead material, they help break down complex parts into their essential components and return carbon, sugars, and nutrients to the soil.
Parasitoids (Parasitoid Wasps): Parasitic insects live on or in a host insect so they can feed on it, usually killing it in the process. Many are parasitic fly or wasp species that inject their eggs into the host. The eggs hatch, then transform into larvae, and because they’re within the host insect, they have a natural food source immediately available.
See our chart below for more information about the beneficial insects we sell in store, including their specific benefits, active time of year, and how to use them in your garden.
How to Attract Beneficial Insects to Your Garden
Creating a diverse environment in your landscape is a guaranteed way to attract beneficial insects to your garden. A diverse garden is one planted with a mixture of plants that have varied bloom time over the entire year, with lots of different flower shapes and in different sizes all interplanted with one another. One excellent approach is to co-plant vegetables with companion flowers such as marigolds, cosmos, and nasturtium. Did you know that planting garlic with peas, lettuce, and celery will naturally help keep aphids away from your crop?
All beneficial insects require a reliable food source, and for some of them, it is specific—ladybugs in their larval stage especially are voracious aphid predators! You can take things a step further by installing a ladybug house. When beneficial insects have a safe place to call home year-round, they’re far more likely to stick around.
When creating your plant collection, remember our beautiful Pacific Northwest native plants! Many wonderful beneficial insects and pollinators rely on our own native flora. For ideas on which natives to plant for a beautiful and diverse garden, check out our blog on the 7 Best Native Plants!
Below is a list of plants that attract and keep beneficial insects in the garden:
Flowers, Vegetables & Herbs to Attract Beneficial Insects
- Angelica – Angelica spp.
- Blazing Star/Gayfeather – Liatris spp.
- Broccoli – Brassica oleracea
- Candytuft – Iberis umbellate
- Carrot – Daucus carota sativus
- Chamomile – Chamaemelum nobile
- Coreopsis – Coreopsis spp.
- Cosmos – Cosmos bipinnatus
- Daisy – Bellis perennis and Leucanthemum
- Dianthus – Dianthus spp.
- Dill – Anethum graveolens
- Fennel – Foeniculum vulgare
- Flowering Sage – Salvia
- Goldenrod – Solidago altissima
- Lavender – Lavendula spp.
- Lemon balm – Melissa offocinale
- Lilyturf – Lirope spicata
- Lovage – Levisticum officianle
- Lupine – Lupinus spp.
- Marigold – Tagetes spp.
- Oregano – Origanum vulgare
- Parsley – Petroselinum crispum
- Phlox – Phlox spp.
- Sage – Salvia spp.
- Statice – Limonium spp.
- Sunflower – Helianthus annuus
- Sweet alyssum – Lobularia maritima
- Thyme – Thymus spp.
- Yarrow – Achillea spp.
- Zinnia – Zinnia spp.
Pacific Northwest Native Plants to Attract Beneficial Insects
- Bugleweed – Ajuga reptans
- Buttertfly Weed – Ascelpias species
- Elderberry – Sambucus
- Evergreen Huckleberry – Vaccinium ovatum
- Gaultheria shallon – Salal
- Joe Pye Weed – Eupatorium purpureum
- Larkspur – Delphium
- Madrone – Arbutus menziesii
- Oregon Grape – Mahonia aquifolium
- Pincushion Flower – Scabiosa columbaria
- Red Flowering Currant – Ribes sanguinium
- Red Twig Dogwood – Cornus sericea
- Snowberry – Symphoricarpos alba
- Stonecrop – Sedum
- Wallflower – Erysimum linifolium
Additionally, planting fruit trees raspberries, and brambling plants provides wonderful habitat and food supply.
How to Protect Beneficial Insects in Your Garden
Because most insecticides are “broad spectrum,” meaning they kill a wide variety of insects, beneficial insects are extremely vulnerable. To promote beneficial insects in your garden, it is our recommendation that insecticides should not be used. In fact, one of our favorite tips for reducing pest populations is to spray with water before using any sort of chemical intervention.
Should you decide to use insecticides in your home landscape, great precaution must be taken to protect beneficial insect populations:
- Whether natural or chemical-based, choose the least toxic product available for the situation.
- Spray only the area(s) on the plant that are affected.
- Spray when many insects are less active—dawn or very early morning.
- Do not spray plants that are in bloom!
Once you choose to use beneficial insects in your garden, protect their survival by avoiding the use of insecticides unless absolutely necessary. Call or visit your local Dennis’ 7 Dees Garden Center—our knowledgeable staff may have alternative suggestions for you!
Beneficial bugs are a brilliant, natural way to reduce issues in your garden. From improving pollination rates, to eating pests, to recycling garden waste, beneficial insects help restore balance, and the end result leads to a healthier, happier, more attractive garden!
Beneficial Bug Resources
- Good Bug, Bad Bug by Jessica Walliser
- The Great Sunflower Project
- Oregon State Extension Services
- WSU Clark County Extension
- Xerces Society