Planting Calendar for ZIP 81639
Based on your local frost dates - last spring frost around Jun 1, first fall frost around Sep 20 - here is when to plant 79 common crops near ZIP 81639.
Last spring frost
Jun 1
First fall frost
Sep 20
Hardiness zone
5a
Vegetables
| Crop | Start seeds indoors | Plant outside | Fall planting by |
|---|---|---|---|
| Tomatoes | Apr 20 | Jun 8 (Transplant out) | - |
| Peppers | Apr 6 | Jun 15 (Transplant out) | - |
| Cucumbers | May 11 | Jun 8 (Transplant out) | Jul 13 |
| Zucchini | May 11 | Jun 8 (Transplant out) | Jul 18 |
| Summer Squash | May 11 | Jun 8 (Transplant out) | Jul 16 |
| Winter Squash | May 11 | Jun 8 (Transplant out) | - |
| Pumpkins | May 11 | Jun 8 (Transplant out) | - |
| Green Beans | - | Jun 1 (Direct sow) | Jul 13 |
| Sweet Corn | - | Jun 8 (Direct sow) | - |
| Melons | May 11 | Jun 15 (Transplant out) | - |
| Watermelon | May 11 | Jun 15 (Transplant out) | - |
| Okra | - | Jun 15 (Direct sow) | - |
| Eggplant | Apr 6 | Jun 15 (Transplant out) | - |
| Lettuce | May 4 | May 4 (Transplant out) | Jul 18 |
| Spinach | - | Apr 20 (Direct sow) | Jul 23 |
| Kale | Apr 20 | May 11 (Transplant out) | Jul 13 |
| Peas | - | Apr 20 (Direct sow) | Jul 8 |
| Carrots | - | May 11 (Direct sow) | Jun 28 |
| Beets | - | May 4 (Direct sow) | Jul 13 |
| Radishes | - | May 4 (Direct sow) | Aug 9 |
| Broccoli | Apr 20 | May 18 (Transplant out) | Jul 3 |
| Cauliflower | Apr 20 | May 18 (Transplant out) | Jun 28 |
| Cabbage | Apr 20 | May 11 (Transplant out) | Jun 28 |
| Onions | Mar 23 | May 4 (Transplant out) | - |
| Potatoes | - | May 18 (Direct sow) | - |
| Swiss Chard | May 4 | May 18 (Transplant out) | Jul 13 |
| Sweet Potatoes | - | Jun 22 (Direct sow) | - |
| Brussels Sprouts | Apr 20 | May 18 (Transplant out) | May 29 |
| Celery | Mar 23 | Jun 8 (Transplant out) | - |
| Leeks | Mar 23 | May 18 (Transplant out) | May 9 |
| Turnips | - | May 18 (Direct sow) | Jul 18 |
| Rutabaga | - | Jun 1 (Direct sow) | Jun 3 |
| Parsnips | - | May 18 (Direct sow) | May 9 |
| Kohlrabi | May 4 | May 18 (Transplant out) | Jul 13 |
| Collard Greens | Apr 20 | May 18 (Transplant out) | Jul 3 |
| Mustard Greens | - | May 18 (Direct sow) | Jul 23 |
| Arugula | - | May 18 (Direct sow) | Jul 28 |
| Bok Choy | May 4 | May 18 (Transplant out) | Jul 18 |
| Green Onions | - | May 18 (Direct sow) | Jul 8 |
| Tomatillos | Apr 20 | Jun 8 (Transplant out) | - |
| Fennel | May 4 | May 18 (Transplant out) | Jun 18 |
| Popcorn | Jun 1 | Jun 15 (Transplant out) | - |
| Black-Eyed Peas | Jun 1 | Jun 15 (Transplant out) | Jun 18 |
| Lima Beans | Jun 1 | Jun 15 (Transplant out) | - |
| Edamame | Jun 1 | Jun 15 (Transplant out) | - |
| Peanuts | Jun 1 | Jun 15 (Transplant out) | - |
| Globe Artichoke | Apr 6 | May 18 (Transplant out) | Jun 8 |
| Horseradish | Jun 1 | May 18 (Transplant out) | - |
| Ground Cherries | Apr 20 | Jun 15 (Transplant out) | - |
| Radicchio | Apr 27 | May 18 (Transplant out) | Jun 28 |
| Endive | Apr 27 | May 18 (Transplant out) | Jun 8 |
| Watercress | May 11 | May 18 (Transplant out) | Jul 8 |
| Sorrel | Apr 20 | May 11 (Transplant out) | Jul 8 |
| Sunchokes | Jun 1 | May 18 (Transplant out) | - |
| Malabar Spinach | Apr 20 | Jun 15 (Transplant out) | - |
| Amaranth Greens | May 11 | Jun 15 (Transplant out) | Jul 23 |
| Luffa Gourd | Apr 20 | Jun 15 (Transplant out) | - |
| New Zealand Spinach | May 4 | Jun 15 (Transplant out) | - |
| Fava Beans | Jun 1 | May 4 (Transplant out) | Jun 13 |
| Chayote | May 4 | Jun 15 (Transplant out) | - |
| Corn Salad | Jun 1 | May 4 (Transplant out) | Jul 8 |
| Bitter Melon | May 4 | Jun 15 (Transplant out) | - |
| Cardoon | Apr 20 | Jun 1 (Transplant out) | - |
Herbs
| Crop | Start seeds indoors | Plant outside | Fall planting by |
|---|---|---|---|
| Basil | Apr 20 | Jun 8 (Transplant out) | - |
| Cilantro | - | May 18 (Direct sow) | Jul 18 |
| Parsley | Apr 6 | Jun 15 (Transplant out) | Jun 23 |
| Dill | - | Jun 8 (Direct sow) | Jul 8 |
| Lemon Balm | Apr 20 | Jun 1 (Transplant out) | - |
| Borage | Jun 1 | Jun 1 (Transplant out) | Jul 13 |
| Chervil | Jun 1 | May 11 (Transplant out) | Jul 13 |
| Lemongrass | Apr 6 | Jun 15 (Transplant out) | - |
| Summer Savory | Apr 20 | Jun 1 (Transplant out) | - |
| Marjoram | Apr 20 | Jun 8 (Transplant out) | - |
| Lovage | Apr 20 | Jun 1 (Transplant out) | Jun 8 |
| Anise Hyssop | Apr 6 | Jun 1 (Transplant out) | - |
| Shiso | Apr 20 | Jun 8 (Transplant out) | - |
| Stevia | Apr 6 | Jun 15 (Transplant out) | - |
| Chamomile | Apr 20 | May 18 (Transplant out) | Jul 3 |
| Tarragon | Jun 1 | Jun 1 (Transplant out) | - |
How to read this calendar
Start seeds indoors is when to sow in trays inside so seedlings are ready to transplant. Plant outside is when to transplant seedlings or direct-sow seed, based on frost tolerance. Fall planting by is the latest date to start a fall crop and still harvest before the first fall frost. Tender crops wait until after the last spring frost; hardy crops can go out earlier.
Computed from NOAA 1991–2020 Climate Normals at Hayden, Co, 5 miles away. Averages for planning, not a forecast. Page updated Aug 4, 2026.