Regional guide

Central Oregon Seed-Starting Schedule

OSU Extension Central Oregon schedule for May 31 frost-free planning, indoor sowing count-backs, and crop-level examples.

Climate signals

OSU Extension's When to start seeds indoors in central Oregon page is by Amy Jo Detweiler and was Published July 2018, Reviewed 2024.
The source is specifically about central Oregon seed-starting timing, not statewide Oregon planting dates.
Most gardeners in central Oregon use May 31 as the average frost-free date, but OSU says to use the date most applicable to your area.
Use the schedule to count back or ahead from the frost-free date for the outdoor planting date, then count back from that date for the indoor sowing date.

Beans use the May 31 example frost-free date, 1 week after for set-out timing, June 7 as the set-out date, 4 weeks indoors, and May 10 as the sow date.
Lettuce uses the May 31 example frost-free date, 2 weeks before for set-out timing, May 17 as the set-out date, 5 weeks indoors, and April 12 as the sow date.
Cool-season rows include Broccoli 4 weeks before the frost-free date and 6 weeks indoors, Brussels sprouts 4 weeks before and 6 weeks indoors, Cabbage 5 weeks before and 6 weeks indoors, Cauliflower 2 weeks before and 6 weeks indoors, Kale 5 weeks before and 6 weeks indoors, Leeks 5 weeks before and 10 weeks indoors, and Peas 4 weeks before and 4 weeks indoors.
Warm-season rows include Corn on the frost-free date and 4 weeks indoors, Cucumbers 1 week after and 3 weeks indoors, Melons 2 weeks after and 3 weeks indoors, Peppers 2 weeks after and 8 weeks indoors, Squash 2 weeks after and 3 weeks indoors, and Tomatoes on the frost-free date and 8 weeks indoors.
Onions are listed 6 weeks before the frost-free date and 10 weeks indoors, but that source row has no conservative catalog link because the catalog onion is a bunching onion.
The source credits the Original chart format courtesy of National Gardening Association and notes it was Previously titled Seed starting schedule.
Use these priority catalog links as crop-level examples for OSU Extension rows, not OSU cultivar recommendations.

These catalog entries match crops covered by the regional timing source; variety-specific details remain tied to each seed entry's own source.

Oregon Four-Region Vegetable Garden A guide for Oregon gardeners who need different planting windows for the coast, western valleys, high elevations, and Columbia/Snake valleys.
Willamette Valley Oregon Garden Calendar OSU EM 9032 Willamette Valley monthly calendar for average-weather timing, soil checks, protected starts, transplants, and crop examples.
Eastern Oregon Seed-Starting Schedule OSU Extension Eastern Oregon schedule for May 21 frost-free timing, semi-arid frost risk, indoor starts, direct seeding, and hardening off.
Oregon Coast Vegetable Climate Guide OSU Extension coastal vegetable guide for mild, rainy, cool-summer gardens, wind, fog, protection, and crop-level catalog examples.