- Leafrolling worms will affect apples and blueberries. Prune off affected leaves and place pheromone traps or spray with approved pesticides.
- Trap moles and gophers as new mounds appear.
- Control spittle bugs and aphids in strawberries and ornamentals, if present; wash off or use insecticidal soap as a contact spray. Follow label directions.
- Fertilize rhododendrons and azaleas; remove spent blossoms.
- Plant chrysanthemums for fall color.
- Plant dahlias, gladioli, and tuberous begonias in mid-May.
- Control cabbage worms in cabbage and cauliflower, 12-spotted cucumber beetle in beans and lettuce, maggot in radishes. Control can involve hand removal, placing barrier screen over newly planted rows, or spraying or dusting with appropriate materials.
- Spray cherries, plums, peaches, and apricots for brown rot blossom blight, if necessary.
- Control aphids with insecticidal soap, a hard spray of water, or hand removal; by promoting natural predators; or by using approved insecticides labeled for the problem plant.
- Tiny holes in foliage and shiny, black beetles on tomato, beets, radishes, and potato indicate flea beetle attack. Treat with Neem, rotenone, Bt, or use nematodes for larvae. Follow label directions.
- Fertilize roses and control rose diseases such as mildew with a registered fungicide. When selecting new roses, choose plants labeled for resistance to diseases.
- Prevent root maggots when planting cabbage family, onions, and carrots, by covering with row covers or screens, or by applying appropriate pesticides.
- Control slugs with bait or traps and by removing or mowing vegetation near garden plots.
- Place pheromone traps in apple trees to detect presence of codling moth. Plan a control program of sprays, baits, or predators when moths are found.
- Monitor broadleaf evergreens for root weevils. Look for notches chewed on new leaves. Mark plants to teat with parasitic nematodes in autumn when soil temperatures are still above 55°F.
- Plant these vegetables (dates vary locally; check with local gardeners):
Oregon coast: snap beans, broccoli, Brussels sprouts, cantaloupes, pickling cucumbers, dill, kale, parsnips, peppers, pumpkins, summer and winter squash, sweet corn, tomatoes.
Western Oregon: mid-May, transplant tomato and pepper seedlings.
Western valleys, Portland, Roseburg, Medford: snap and lima beans, Brussels sprouts, cantaloupes, slicing and pickling cucumbers, dill, eggplant, kale, peppers, pumpkins, summer and winter squash, onions, potatoes, tomatoes, watermelon.
Lower elevations, eastern Oregon (dates vary widely): snap and lima beans, beets, celery, sweet corn, slicing and pickling cucumbers, dill, kale, kohlrabi, onions, parsley, parsnips, peppers, white potatoes, pumpkins, summer and winter squash, tomatoes.
High elevations, central and eastern Oregon: prepare garden soil for spring planting.
Central Oregon and higher elevations of eastern Oregon: early May-onions; mid-May to late May-beets, broccoli, Brussels sprouts, cabbage, carrots, cauliflower, chives, endive, spinach; mid-May to early June-dill, kale, kohlrabi, parsley, parsnips, potatoes; late May to early June-snap beans, sweet corn, cucumbers, peppers, pumpkins, summer squash, tomatoes.
Columbia and Snake River valleys, Ontario: cantaloupes, dill, eggplant, kale, okra, peppers, sweet potatoes, tomatoes, watermelon.