The source says gardening in Eastern Oregon has unpredictable spring frosts and a semi-arid climate.
Regional guide
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.
Regional timing
Current regional planting plan
OSU Extension Eastern Oregon schedule for May 21 frost-free timing, semi-arid frost risk, indoor starts, direct seeding, and hardening off.
Source-backed timing
OSU Extension Eastern Oregon seed-starting schedule
Eastern Oregon Seeds
7 climate signals
Source
source cues
Local
conditions
- OSU Extension's Eastern Oregon seed-starting schedule by Russell Smith-Ollivierre was Revised April 2025.
- The source says gardening in Eastern Oregon has unpredictable spring frosts and a semi-arid climate.
- The schedule is based on the local average frost-free date, and most gardeners in Eastern Oregon use May 21.
- Catalog priority
- 20 priority crops 20 catalog examples
- Climate checks
- 7 climate signals 5 planning notes
- Timing basis
- Use regional source signals source guidance first
Detroit Dark Red Beet, Waltham 29 Broccoli, Long Island Improved Brussels Sprouts, Golden Acre Cabbage
Cool-season transplant 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, Lettuce 2 weeks before and 5 weeks indoors, and Peas 4 weeks before and 4 weeks indoors.
Calendar
Convert regional timing into dated sowing, transplant, and harvest jobs.
Frost dates
Keep hardiness zone context separate from local first and last frost dates.
All regions
Compare this guide with the broader regional atlas.
Oregon Regions
A guide for Oregon gardeners who need different planting windows for the coast, western valleys, high elevations, and Columbia/Snake valleys.
Climate signals
- OSU Extension's Eastern Oregon seed-starting schedule by Russell Smith-Ollivierre was Revised April 2025.
- The source says gardening in Eastern Oregon has unpredictable spring frosts and a semi-arid climate.
- The schedule is based on the local average frost-free date, and most gardeners in Eastern Oregon use May 21.
- Use the schedule to count back or forward from the frost-free date for the outdoor planting date, then count back further for the indoor sowing date when crops are started indoors.
- Frost-tolerant plants can withstand light frost from 28 to 32 degrees F and in some cases below 28 degrees F.
- Frost-sensitive plants are susceptible to damage or death at 32 degrees F or below.
- Adjust the schedule based on local microclimates and weather patterns.
Planning notes
- Direct-seed rows include Beets 6 weeks before the frost-free date, Carrots 4 weeks before and Direct seed, Spinach 5 weeks before and Direct seed, Swiss chard 4 weeks before and Direct seed, and Radishes 6 weeks before and Direct seed.
- Cool-season transplant 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, Lettuce 2 weeks before and 5 weeks indoors, and Peas 4 weeks before and 4 weeks indoors.
- Warm-season rows include Beans 1 week after the frost-free date and 4 weeks indoors, Corn 1 week after and 4 weeks indoors, Cucumbers 1 week after and 3 weeks indoors, Eggplant 2 weeks after and 9 weeks indoors, Melons 2 weeks after and 3 weeks indoors, Peppers 2 weeks after and 8 weeks indoors, and Tomatoes on the frost-free date and 8 weeks indoors.
- Harden transplants off for 7 to 10 days by starting in a sheltered, shady spot for a few hours each day, then increasing time outside and sun exposure.
- Use these priority links as crop-level catalog examples for OSU Extension rows, not as onion, squash, watermelon, edamame, yardlong bean, flower, or exact cultivar recommendations.
Catalog crop examples
These catalog entries match crops covered by the regional timing source; variety-specific details remain tied to each seed entry's own source.
- Detroit Dark Red Beet Vegetable · Cool · 58 days
- Waltham 29 Broccoli Vegetable · Cool · 74 days
- Long Island Improved Brussels Sprouts Vegetable · Cool · 100 days
- Golden Acre Cabbage Vegetable · Cool · 64 days
- Danvers 126 Carrot Vegetable · Shoulder · 70 days
- Snowball Y Cauliflower Vegetable · Cool · 70 days
- Lacinato Kale Vegetable · Cool · 60 days
- American Flag Leek Vegetable · Cool · 120 days
- Black Seeded Simpson Lettuce Vegetable · Cool · 45 days
- Sugar Snap Pea Vegetable · Cool · 62 days
- Bloomsdale Spinach Vegetable · Cool · 42 days
- Bright Lights Swiss Chard Vegetable · Shoulder · 55 days
- French Breakfast Radish Vegetable · Cool · 28 days
- Provider Bush Bean Vegetable · Warm · 50 days
- Golden Bantam Sweet Corn Vegetable · Warm · 80 days
- Marketmore 76 Cucumber Vegetable · Warm · 58 days
- Black Beauty Eggplant Vegetable · Warm · 80 days
- Hale's Best Jumbo Melon Vegetable · Warm · 85 days
- California Wonder Pepper Vegetable · Warm · 72 days
- Roma Tomato Vegetable · Warm · 76 days
Related regional guides
- 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.
- Central Oregon Seed-Starting Schedule OSU Extension Central Oregon schedule for May 31 frost-free planning, indoor sowing count-backs, and crop-level examples.
- Oregon Coast Vegetable Climate Guide OSU Extension coastal vegetable guide for mild, rainy, cool-summer gardens, wind, fog, protection, and crop-level catalog examples.