Trap moles and gophers as new mounds appear.
Control spittle bugs and aphids in strawberries and ornamentals, if present; wash off. Follow label directions.
Fertilize rhododendrons and azaleas; remove spent blossoms
Plant chrysanthemums for fall color.
Plant dahlias 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.
Control aphids with soap, a hard spray of water, hand removal; by promoting natural predators;.
Tiny holes in foliage and shiny, black beetles on tomato, beets, radishes, and potato indicate flea beetle attack. Use nematodes for larval stage as recommended by product label.
Fertilize roses and control rose diseases. 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, screens.
Control slugs with bait or traps, or 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.
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.