When to Plant Dahlias in Colorado
In a typical Colorado location, plant outdoors May 10 – May 24. Across the state, the outdoor planting window starts as early as Apr 21 in Grand Junction and as late as Jun 28 in Edwards.
Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive.
Dahlias Planting Dates by City
| City | Plant outdoors |
|---|---|
| Denver | May 7 – May 21 |
| Colorado Springs | May 10 – May 24 |
| Aurora | May 11 – May 25 |
| Fort Collins | May 9 – May 23 |
| Lakewood | May 10 – May 24 |
| Thornton | May 9 – May 23 |
| Westminster | May 9 – May 23 |
| Arvada | May 12 – May 26 |
| Centennial | May 12 – May 26 |
| Pueblo | May 7 – May 21 |
| Greeley | May 9 – May 23 |
| Boulder | May 13 – May 27 |
| Highlands Ranch | May 12 – May 26 |
| Longmont | May 14 – May 28 |
| Loveland | May 17 – May 31 |
| Broomfield | May 9 – May 23 |
| Grand Junction | Apr 21 – May 5 |
| Castle Rock | May 16 – May 30 |
| Commerce City | May 11 – May 25 |
| Parker | May 16 – May 30 |
| Littleton | May 9 – May 23 |
| Northglenn | May 9 – May 23 |
| Brighton | May 10 – May 24 |
| Dakota Ridge | May 9 – May 23 |
| Englewood | May 9 – May 23 |
| Security-Widefield | May 10 – May 24 |
| Windsor | May 10 – May 24 |
| Ken Caryl | May 9 – May 23 |
| Wheat Ridge | May 12 – May 26 |
| Pueblo West | May 3 – May 17 |
Showing the 30 most populous of 65 Colorado cities. Dates are estimates from each city's NOAA frost normals and university extension timing guidelines. See all Colorado cities.
Frequently Asked Questions
When should I plant dahlias in Colorado?
In a typical Colorado location, plant outdoors May 10 – May 24. Across the state, the outdoor planting window starts as early as Apr 21 in Grand Junction and as late as Jun 28 in Edwards.
When is the last frost in Colorado?
The average last spring frost in Colorado ranges from April 14 in Grand Junction to June 21 in Edwards, based on NOAA 1991–2020 climate normals.
How long do dahlias take to grow?
Dahlias typically take 90–120 days from planting to harvest. Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive.
Other Crops in Colorado
- Tomatoes
- Peppers
- Eggplant
- Cucumbers
- Zucchini
- Winter Squash
- Pumpkins
- Watermelon
- Cantaloupe
- Corn
- Green Beans
- Peas
- Lettuce
- Spinach
- Kale
- Arugula
- Swiss Chard
- Broccoli
- Cauliflower
- Cabbage
- Brussels Sprouts
- Carrots
- Beets
- Radishes
- Turnips
- Onions
- Garlic
- Potatoes
- Sweet Potatoes
- Asparagus
- Basil
- Cilantro
- Parsley
- Dill
- Oregano
- Thyme
- Sunflowers
- Zinnias
- Marigolds
- Cosmos
- Nasturtiums
When to plant dahlias in other states