Spring Beneficial Insects


Ladybugs, also known as lady beetles, are beneficial predaceous insects. They are well known for their appetite for aphids and are great for releasing in a greenhouse as it provides a closed and controlled environment.

Releasing Ladybugs

After receiving your live ladybugs, leave bag sealed and place in refrigerator to calm the beetles from their transporting experience. Release at early evening as night time allows them to settle in, find food and water, and get acquainted with their new space, your home garden. Sprinkle some water in your garden before their release to provide immediate moisture. Once they’re settled in, their moisture needs will be met from eating aphids and other plant pests.

Nematodes in Spring

Prevent plant damage with beneficial nematodes.

Beneficial nematodes provide one of the most effective and easy-to-use biological controls for certain difficult insect pests.  Beneficial nematodes only attack insects with a soil-dwelling development stage, so they pose no risks to other animals nor to most other beneficial insects and pollinators.  Because they are sensitive to sunlight, drought, and also restricted by cold soil temperatures, in western Oregon nematodes are mostly applied in the fall or the spring, on moist soil and during the cool hours of morning or evening.

Spring Application

Wait for soil to warm a bit for best results, as early as April or as late as mid June.  Where pest problems are extensive, try a second application about 2 weeks after the first.

-Apply nematodes to lawn to control cutworms, fleas, and sod webworm.  Spring applications are unlikely to provide adequate European cranefly control.
-Apply nematodes to the roots of rhododendrons, azaleas, and similar broad-leaf evergreens to control root weevils; the fall control is better, but spring application can be effective if fall is missed or as a follow-up for very bad infestations.
-Apply nematodes to garden areas to control or reduce your local populations of many beetles (including cucumber beetle), cutworms, and wireworms.

To use beneficial nematodes, first get a rough measurement of how large of an area you need to treat.  The common small size package of 10 million nematodes (no, I didn’t count them!) can treat an urban garden, a dozen or more mature shrubs, or a small front yard – maybe 2000 square feet.  If you are trying to stretch them as far as possible, apply through a sprayer – but if you are treating a few raised beds or rhododendrons it will be easier to use a watering can.

With that in mind, create a solution of nematodes by soaking the media they come on in a bucket with a gallon or so of water.  Skim the media off the top and scatter it into the treatment area; for a small area add enough solution to half fill your watering can and top it off with more water, then pour as evenly as possible over the treatment area.  For larger areas, pour the solution through a filter into your sprayer.  A gallon run through a sprayer should cover about 750 square feet, so if you are doing an entire 2000 square foot yard, mix one part of your solution with two parts water to make enough volume for coverage.

See package or ask your local nursery for additional application suggestions or advice.  A light watering after application is recommended (if the rain doesn’t do the job for you).