Frost Dates & Planting Calendar for Prineville, OR
Plan your garden around Prineville, OR's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.
Last Spring Frost
June 1
Safe Jun 22
Typical Jun 1
Risky May 8
First Fall Frost
September 22
Safe Aug 31
Typical Sep 22
Risky Oct 9
Growing Season
113 days
Typical last frost to typical first frost.
USDA Hardiness Zone
Zone 6b
A classic four-season climate with cold winters and a solid summer growing season.
Data: NOAA station PRINEVILLE, OR US, 0.5 km away.
—
days until the typical last spring frost
Monthly Temperatures
Avg. high
Avg. temp
Avg. low
Planting Calendar
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Tomato | Apr 6 – Apr 20 | — | Jun 8 – Jun 15 | — | 60–85 days | Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed. |
| Pepper | Mar 23 – Apr 6 | — | Jun 8 – Jun 22 | — | 60–90 days | Slow to germinate; start indoors 8-10 weeks before last frost. Transplant only once nights stay above 55F, 1-3 weeks after last frost. |
| Eggplant | Mar 23 – Apr 6 | — | Jun 15 – Jun 22 | — | 65–85 days | Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant. |
| Cucumber | May 4 – May 11 | Jun 8 – Jun 15 | Jun 8 – Jun 15 | — | 50–65 days | Can be started indoors 3-4 weeks before transplanting, or direct-sown 1-2 weeks after last frost once soil is warm. |
| Zucchini | May 11 – May 18 | Jun 8 – Jun 22 | Jun 8 – Jun 15 | — | 45–55 days | Fast-growing squash; direct sow 1-3 weeks after last frost, or start indoors 2-3 weeks early for a head start. |
| Winter Squash | May 4 – May 11 | Jun 8 – Jun 22 | Jun 8 – Jun 15 | — | 80–110 days | Long season; direct sow after soil warms, or start indoors 3-4 weeks before last frost in short-season climates. |
| Pumpkin | — | Jun 8 – Jun 22 | — | — | 90–120 days | Direct sow 1-3 weeks after last frost; back-time from your first fall frost so the 90-120 day maturity window lands before it. |
| Watermelon | May 4 – May 11 | — | Jun 15 – Jun 22 | — | 70–90 days | Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost. |
| Cantaloupe | May 4 – May 11 | — | Jun 15 – Jun 22 | — | 70–90 days | Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting. |
| Corn | — | Jun 1 – Jun 15 | — | — | 60–100 days | Direct sow at last frost to 2 weeks after, once soil reaches 60F; does not transplant well. Succession sow every 2 weeks. |
| Green Bean | — | Jun 1 – Jun 15 | — | — | 50–65 days | Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush. |
| Pea | — | Apr 20 – May 4 | — | — | 55–70 days | Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Lettuce | — | May 4 – May 18 | — | Jul 28 – Aug 11 | 45–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts. |
| Spinach | — | Apr 20 – May 4 | — | Jul 28 – Aug 11 | 40–50 days | Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Kale | — | May 4 – May 18 | — | Jul 14 – Jul 28 | 50–65 days | Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants. |
| Arugula | — | May 4 – May 18 | — | Aug 11 – Aug 18 | 30–40 days | Fast-growing, cold-tolerant green; direct sow 2-4 weeks before last frost, succession sow every 2-3 weeks. |
| Swiss Chard | — | May 11 – May 25 | — | — | 50–60 days | Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too. |
| Broccoli | Apr 13 – Apr 27 | — | May 11 – May 18 | Jul 21 – Jul 28 | 55–80 days | Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost). |
| Cauliflower | Apr 13 – Apr 27 | — | May 18 – May 25 | Jul 14 – Jul 21 | 55–85 days | Fussier than broccoli about temperature swings; start indoors 5-7 weeks before last frost, transplant 1-2 weeks before last frost. |
| Cabbage | Apr 13 – Apr 27 | — | May 4 – May 18 | Jul 14 – Jul 28 | 60–100 days | Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost. |
| Brussels Sprouts | Apr 13 – Apr 27 | — | May 11 – May 25 | — | 90–110 days | Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost. |
| Carrot | — | May 4 – May 18 | — | Jun 30 – Jul 14 | 60–80 days | Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked. |
| Beet | — | May 4 – May 18 | — | Jul 14 – Jul 28 | 50–65 days | Direct sow 2-4 weeks before last frost; tolerates light frost. |
| Radish | — | Apr 27 – May 11 | — | Aug 11 – Aug 25 | 22–30 days | Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked. |
| Turnip | — | May 4 – May 18 | — | Jul 14 – Jul 28 | 40–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. |
| Onion | Mar 23 – Apr 6 | — | May 4 – May 18 | — | 90–120 days | Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings. |
| Garlic | — | — | — | Aug 25 – Sep 8 | 240–270 days | Fall-planted crop only; not planted in spring in most climates. |
| Potato | — | May 4 – May 18 | — | — | 70–120 days | Plant seed potatoes 2-4 weeks before last frost, as soon as soil can be worked and is above 45F; light frost on emerging foliage is usually tolerated. |
| Sweet Potato | — | — | Jun 15 – Jun 29 | — | 90–120 days | Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive. |
| Asparagus | — | — | May 4 – May 18 | — | 730–1095 days | Perennial; plant crowns 2-4 weeks before last frost as soon as soil can be worked. Takes 2-3 years to full production. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Basil | Apr 20 – Apr 27 | — | Jun 8 – Jun 15 | — | 50–70 days | Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm. |
| Cilantro | — | May 11 – May 25 | — | Jul 28 – Aug 11 | 45–70 days | Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring. |
| Parsley | Apr 6 – Apr 20 | — | May 18 – May 25 | — | 70–90 days | Slow to germinate; start indoors 6-8 weeks before last frost, transplant 1-2 weeks before last frost (biennial, cold-tolerant). |
| Dill | — | May 11 – May 25 | — | — | 40–60 days | Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer. |
| Oregano | Apr 6 – Apr 20 | — | Jun 1 – Jun 8 | — | 80–90 days | Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date. |
| Thyme | Apr 6 – Apr 20 | — | Jun 1 – Jun 8 | — | 85–95 days | Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Sunflower | — | Jun 8 – Jun 22 | — | — | 70–100 days | Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting. |
| Zinnia | May 4 – May 11 | Jun 8 – Jun 22 | Jun 8 – Jun 15 | — | 60–70 days | Frost-tender; direct sow 1-3 weeks after last frost, or start indoors 3-4 weeks early for earlier blooms. |
| Marigold | Apr 20 – May 4 | — | Jun 8 – Jun 15 | — | 45–60 days | Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed. |
| Cosmos | May 4 – May 11 | Jun 8 – Jun 22 | Jun 8 – Jun 15 | — | 60–90 days | Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early. |
| Nasturtium | — | Jun 8 – Jun 22 | — | — | 50–65 days | Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed. |
| Dahlia | — | — | Jun 8 – Jun 22 | — | 90–120 days | Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive. |
Date ranges are estimates based on university extension guidelines and this city's NOAA frost normals — not a guarantee. Scroll to see all columns on narrow screens.
Frequently Asked Questions
When is the last frost in Prineville, OR?
Based on 1991–2020 NOAA climate normals for the PRINEVILLE, OR US station, the last spring frost in Prineville typically falls around June 1. A cautious gardener might wait until June 22 (only a 10% chance of a later frost), while May 8 marks an earlier, higher-risk planting date.
When is the first frost in Prineville, OR in fall?
The first fall frost in Prineville typically arrives around September 22. To stay safe, assume frost could start as early as August 31; in milder years it can hold off until October 9.
How long is the growing season in Prineville, OR?
Prineville's average frost-free growing season is about 113 days, running from the typical last spring frost (June 1) to the typical first fall frost (September 22).
What USDA hardiness zone is Prineville, OR in?
Prineville, OR is in USDA plant hardiness zone 6b, per the USDA's 2023 Plant Hardiness Zone Map. A classic four-season climate with cold winters and a solid summer growing season.