OSU Gardening Calendar

August

Planning

Dampwood termites begin flying late this month. Make sure your home is free of wet wood or places where wood and soil are in contact.
Optimal time for establishing a new lawn is August through Mid-September.

Maintenance and Clean Up

Make compost of lawn clippings and garden plants that are ready to be recycled. Don't use clippings if lawn has been treated with herbicide, including "weed-and-feed" products. Don't compost diseased plants unless you are using the "hot compost" method (120° to 150°F).
Fertilize cucumbers, summer squash, and broccoli to maintain production while you continue harvesting.
Clean and fertilize strawberry beds.
Use mulch to protect ornamentals and garden plants from hot weather damage If needed, provide temporary shade, especially for recent plantings.
Camellias need deep watering to develop flower buds for next spring.
Prune raspberries, boysenberries, and other caneberries after harvest. Check raspberries for holes made by crown borers, near the soil line, at base of plant. Remove infested wood before adults emerge (approximately mid-August).
Monitor garden irrigation closely so crops and ornamentals don't dry out.
If a green lawn is desired, make sure lawn areas are receiving adequate water (approximately 0.5 to 1.5 inches per week from June through August). Deep watering less often is more effective than frequent shallow watering. Measure your water use by placing an empty tuna can where your irrigation water lands.
Western Oregon: Prune out dead fruiting canes in trailing blackberry and train new primocanes prior to end of month.
High elevations, central and eastern Oregon: Prune away excess vegetation and new blossoms on tomatoes after mid-August. Concentrate on ripening set fruit.

Planting/Propagation

Plant winter cover crops in vacant space in the vegetable garden.
Plant winter kale, Brussels sprouts, turnips, parsnips, parsley, and Chinese cabbage.
Western Oregon: Mid-summer planting of peas; use enation-virus-resistant varieties, plant fall crops of cabbage, cauliflower, and broccoli.
Oregon coast: Plant spinach.
Western valleys, Portland, Roseburg, Medford: Plant cauliflower, broccoli, Brussels sprouts, spinach, turnips, and parsnips.
Columbia and Snake River valleys, Ontario: Plant Chinese cabbage, and endive.

Pest Monitoring and Management

Check apple maggot traps; spray tree if needed.
Control yellowjackets and wasps with traps and lures as necessary. Keep in mind they are beneficial insects and help control pest insects in the home garden.
First week: If necessary, spray for walnut husk fly.
First week: If necessary second spray of peach and prune trees for root borers.
First week: If necessary, second spray of filbert trees for filbertworm.
Check for root weevils in ornamental shrubs and flowers; codling moth and spider mite in apple trees; scale insects in camellias, holly and maples. Treat as necessary.
Watch for corn earworm on early corn. Treat as needed.
Control caterpillars on leafy vegetables, as needed, with Bt-k, or by hand picking and removal.
For mite control on ornamentals and most vegetables, hose off foliage, spray with approved miticide if necessary.
Remove cankered limbs from fruit and nut trees for control of diseases such as apple anthracnose and bacterial canker of stone fruit. Sterilize tools before each new cut.
Willamette Valley: Corn may need protection from earworm. Spray new silks with appropriate pesticides if necessary.
East of Cascades: Check for tomato hornworm. Remove them if found.
Coastal and western valleys: Spray potatoes and tomatoes for early and late blight.

Download a PDF of the August Calendar for easy printing.

Updated September 10, 2009.

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OSU Gardening Calendar

August