Planting Calendar for ZIP 80474
Based on your local frost dates - last spring frost around Jun 21, first fall frost around Sep 2 - here is when to plant 79 common crops near ZIP 80474.
Last spring frost
Jun 21
First fall frost
Sep 2
Hardiness zone
5b
Vegetables
| Crop | Start seeds indoors | Plant outside | Fall planting by |
|---|---|---|---|
| Tomatoes | May 10 | Jun 28 (Transplant out) | - |
| Peppers | Apr 26 | Jul 5 (Transplant out) | - |
| Cucumbers | May 31 | Jun 28 (Transplant out) | Jun 25 |
| Zucchini | May 31 | Jun 28 (Transplant out) | Jun 30 |
| Summer Squash | May 31 | Jun 28 (Transplant out) | Jun 28 |
| Winter Squash | May 31 | Jun 28 (Transplant out) | - |
| Pumpkins | May 31 | Jun 28 (Transplant out) | - |
| Green Beans | - | Jun 21 (Direct sow) | Jun 25 |
| Sweet Corn | - | Jun 28 (Direct sow) | - |
| Melons | May 31 | Jul 5 (Transplant out) | - |
| Watermelon | May 31 | Jul 5 (Transplant out) | - |
| Okra | - | Jul 5 (Direct sow) | - |
| Eggplant | Apr 26 | Jul 5 (Transplant out) | - |
| Lettuce | May 24 | May 24 (Transplant out) | Jun 30 |
| Spinach | - | May 10 (Direct sow) | Jul 5 |
| Kale | May 10 | May 31 (Transplant out) | Jun 25 |
| Peas | - | May 10 (Direct sow) | Jun 20 |
| Carrots | - | May 31 (Direct sow) | Jun 10 |
| Beets | - | May 24 (Direct sow) | Jun 25 |
| Radishes | - | May 24 (Direct sow) | Jul 22 |
| Broccoli | May 10 | Jun 7 (Transplant out) | Jun 15 |
| Cauliflower | May 10 | Jun 7 (Transplant out) | Jun 10 |
| Cabbage | May 10 | May 31 (Transplant out) | Jun 10 |
| Onions | Apr 12 | May 24 (Transplant out) | - |
| Potatoes | - | Jun 7 (Direct sow) | - |
| Swiss Chard | May 24 | Jun 7 (Transplant out) | Jun 25 |
| Sweet Potatoes | - | Jul 12 (Direct sow) | - |
| Brussels Sprouts | May 10 | Jun 7 (Transplant out) | May 11 |
| Celery | Apr 12 | Jun 28 (Transplant out) | - |
| Leeks | Apr 12 | Jun 7 (Transplant out) | Apr 21 |
| Turnips | - | Jun 7 (Direct sow) | Jun 30 |
| Rutabaga | - | Jun 21 (Direct sow) | May 16 |
| Parsnips | - | Jun 7 (Direct sow) | Apr 21 |
| Kohlrabi | May 24 | Jun 7 (Transplant out) | Jun 25 |
| Collard Greens | May 10 | Jun 7 (Transplant out) | Jun 15 |
| Mustard Greens | - | Jun 7 (Direct sow) | Jul 5 |
| Arugula | - | Jun 7 (Direct sow) | Jul 10 |
| Bok Choy | May 24 | Jun 7 (Transplant out) | Jun 30 |
| Green Onions | - | Jun 7 (Direct sow) | Jun 20 |
| Tomatillos | May 10 | Jun 28 (Transplant out) | - |
| Fennel | May 24 | Jun 7 (Transplant out) | May 31 |
| Popcorn | Jun 21 | Jul 5 (Transplant out) | - |
| Black-Eyed Peas | Jun 21 | Jul 5 (Transplant out) | May 31 |
| Lima Beans | Jun 21 | Jul 5 (Transplant out) | - |
| Edamame | Jun 21 | Jul 5 (Transplant out) | - |
| Peanuts | Jun 21 | Jul 5 (Transplant out) | - |
| Globe Artichoke | Apr 26 | Jun 7 (Transplant out) | May 21 |
| Horseradish | Jun 21 | Jun 7 (Transplant out) | - |
| Ground Cherries | May 10 | Jul 5 (Transplant out) | - |
| Radicchio | May 17 | Jun 7 (Transplant out) | Jun 10 |
| Endive | May 17 | Jun 7 (Transplant out) | May 21 |
| Watercress | May 31 | Jun 7 (Transplant out) | Jun 20 |
| Sorrel | May 10 | May 31 (Transplant out) | Jun 20 |
| Sunchokes | Jun 21 | Jun 7 (Transplant out) | - |
| Malabar Spinach | May 10 | Jul 5 (Transplant out) | - |
| Amaranth Greens | May 31 | Jul 5 (Transplant out) | Jul 5 |
| Luffa Gourd | May 10 | Jul 5 (Transplant out) | - |
| New Zealand Spinach | May 24 | Jul 5 (Transplant out) | - |
| Fava Beans | Jun 21 | May 24 (Transplant out) | May 26 |
| Chayote | May 24 | Jul 5 (Transplant out) | - |
| Corn Salad | Jun 21 | May 24 (Transplant out) | Jun 20 |
| Bitter Melon | May 24 | Jul 5 (Transplant out) | - |
| Cardoon | May 10 | Jun 21 (Transplant out) | - |
Herbs
| Crop | Start seeds indoors | Plant outside | Fall planting by |
|---|---|---|---|
| Basil | May 10 | Jun 28 (Transplant out) | - |
| Cilantro | - | Jun 7 (Direct sow) | Jun 30 |
| Parsley | Apr 26 | Jul 5 (Transplant out) | Jun 5 |
| Dill | - | Jun 28 (Direct sow) | Jun 20 |
| Lemon Balm | May 10 | Jun 21 (Transplant out) | - |
| Borage | Jun 21 | Jun 21 (Transplant out) | Jun 25 |
| Chervil | Jun 21 | May 31 (Transplant out) | Jun 25 |
| Lemongrass | Apr 26 | Jul 5 (Transplant out) | - |
| Summer Savory | May 10 | Jun 21 (Transplant out) | - |
| Marjoram | May 10 | Jun 28 (Transplant out) | - |
| Lovage | May 10 | Jun 21 (Transplant out) | May 21 |
| Anise Hyssop | Apr 26 | Jun 21 (Transplant out) | - |
| Shiso | May 10 | Jun 28 (Transplant out) | - |
| Stevia | Apr 26 | Jul 5 (Transplant out) | - |
| Chamomile | May 10 | Jun 7 (Transplant out) | Jun 15 |
| Tarragon | Jun 21 | Jun 21 (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 Boulder 14 W, Co, 7.9 miles away. Averages for planning, not a forecast. Page updated Aug 4, 2026.