As summer brings out our gardens’ glory, pests and weeds are sure to follow. Metro Natural Gardening Expert Carl Grimm showed us how to deal with these outdoor annoyances without resorting to toxic chemicals.
Do your petunia petals look positively ragged? It may be the work of budworms. Chop off the affected flowers and search the base of the plant for little green caterpillars – then smash ‘em or snip ‘em in half. If you have too many to use hand-to-hand combat, try using natural bT, a safe-to-humans-and-pets bacterium from the nursery. But don’t spray it all over your garden – it kills all kinds of butterfly larvae.
Powdery mildew? Pow!
If a white powder seems to dust the leaves of your squash, bee balm, dogwood or roses, you may have a case of powdery mildew. Don’t despair. Just chop off the affected leaves and buds, water more consistently and scratch some crushed eggshells, lime or other calcium source into your soil, along with a topdressing of compost.
If thousands of tiny, slow-moving insects cover your rose buds, broccoli heads, nasturtium stems or other plants, you probably have aphids. These little creatures can multiply fast and transmit plant disease, but a strong blast of water can kill them as dead as a pesticide. After getting knocked off a plant, they are almost surely down for the count. To keep them from having so many pregnant babies (aphids are usually born pregnant!), use less nitrogen fertilizer and include a trace-mineral fertilizer like kelp or greensand.
Leaf miner mayhem?
Do your spinach and Swiss chard look like there are tunnels running throughout the older leaves? These are the signature of leaf miners. No worries – just chop off and compost the affected leaves and harvest the younger ones more often so the leaf-mining fly larvae don’t have time to do their dirty work.
Wrestling weeds – mano-a-mano
Hand pulling by the root is the most effective method of removing weeds. Always slap some mulch down on the soil or stick in a new plant wherever you pull a weed.
Free resources from Metro
Natural Gardening booklet – describes our region’s most common pests, weeds and diseases and how to control them naturally, including with beneficial insects.
Grow Smart, Grow Safe – a consumer guide to the health and environmental impacts of 600 garden products, now available online at www.growsmartgrowsafe.org.
For publications and more information about natural gardening, visit www.oregonmetro.gov/garden or call 503-234-3000.