First week: Spray cherry trees for cherry fruit fly and brown rot if fruit is ripening. Spray for codling moth and scab in apple and pear trees. Continue use of pheromone traps for insect pest detection.
Apples and crabapples that are susceptible to scab disease will begin dropping leaves as weather warms. Rake and destroy fallen leaves; spray with summer-strength lime sulfur, wettable sulfur, Immunox or Captan.
Plant dahlias and gladioli.
Learn to identify beneficial insects and plant some insectory plants (alyssum, phacelia, coriander, candytuft, sunflower, yarrow, dill) to attract them to your garden. Check with local nurseries for best selections.
Lawn mowing: Set blade at 3/4-inch to 1-inch for bentgrass lawns; 1 1/2 to 2 1/2 inches for bluegrasses, fine fescues and ryegrasses.
Spray with Orthene to control adult root weevils in rhododendrons, azaleas, primroses and other ornamentals. Or, use beneficial nematodes if soil temperature is above 55 degrees.
Remove seed pods from rhododendrons and azaleas after blooms have dropped.
Prune lilacs, forsythia, rhododendrons and azaleas after blooming.
Fertilize vegetable garden one month after plants emerge by side dressing alongside the rows.
Harvest thinnings from new plantings of lettuce, onion and chard.
Construct trellises for tomatoes, cucumbers, pole beans and vining ornamentals.
Use organic mulches to conserve soil moisture. An inch or two of sawdust, barkdust or composted leaves will minimize loss of water through evaporation.
Pick ripe strawberries regularly to avoid fruit-rotting diseases.
Blossoms on squash and cucumbers begin to drop: nothing to worry about.
Control garden weeds by pulling, hoeing or mulching.
Control aphids on vegetables as needed by hosing off with water or by using insecticidal soap or a registered insecticide.
Watch for cabbage worms, 12-spotted beetles on beans and lettuce, flea beetles in lettuce. Remove the insect pests or treat with labeled pesticides.
Spray peas as first pods form, if necessary, to control weevils.
After normal fruit drop in June, consider thinning the remainder to produce a larger crop of fruit.
Late this month, begin to monitor for late blight on tomatoes.
Birch trees dripping means aphids are present. Control as needed.
If indicated, spray cherries at weekly intervals for fruit fly.
Last week: second spray for codling moth and scab in apple and pear trees.
Move houseplants outside for cleaning, grooming, repotting and summer growth.
Make sure raised beds receive enough water for plants to stay free of drought stress.
Plant sweet corn, other tender vegetables.
Apply fertilizer to lawns.
Oregon State University Extension Service encourages sustainable gardening practices. Always identify and monitor problems before acting. First consider cultural controls, then physical, biological, and chemical controls (which include insecticidal soaps, horticultural oils, botanical insecticides, organic and synthetic pesticides). Always consider the least toxic approach first. For more information, contact your local office of the OSU Extension Service.
