What to plant this week in Denver, CO
With average last frost in Denver hovering around April 21, your garden is now officially in the swing of late spring growth and early summer harvests. While the air still carries that high-desert chill, you can aggressively plant warm-weather crops like okra and watermelon while simultaneously harvesting your mature tomatoes and peppers.
The next 7 days
Denver, COGrowing in Denver right now
- Take advantage of Denver's rapid soil warming by sowing heat-loving seeds like French marigolds and nasturtiums directly into cool ground this week to avoid shock.
- Be mindful that while rain is often delayed until later in the growing season, check your beds for dry cracks caused by wind; mulch heavily around squash and zucchini to retain moisture before summer storms arrive.
- As the sun sets earlier than in lower zones, provide evening shade or row covers for young transplants if a late spring freeze threatens after April 21.
- Leverage the city's thin soil profile by incorporating compost into raised beds this week to improve water retention and nutrient availability for your expanding harvest.
Sow this week
7 crops- Bush Bean
- Cucumber
- French Marigold
- Nasturtium
- Okra
- Yellow Summer Squash
- Zucchini
Transplant this week
Nothing is due to go out this week.
Harvest soon
58 crops- Anaheim (New Mexico) Pepper
- Banana Pepper
- Basil
- Beefsteak Tomato
- Beet
- Bell Pepper
- Borage
- Brussels Sprouts
- Bush Bean
- Cantaloupe
- Carrot
- Cayenne Pepper
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dahlia
- Edamame
- Eggplant
- Fennel
- Flour Corn
- French Marigold
- Garden Geranium (Zonal)
- Garden Verbena
- Garlic
- Honeydew Melon
- Jalapeño
- Lantana
- Lima Bean
- Malabar Spinach
- Marconi Pepper
- Nasturtium
- Okra
- Ornamental Sweet Potato Vine
- Parsley
- Parsnip
- Petunia
- Poblano Pepper
- Pole Bean
- Potato
- Roma Tomato
- Rutabaga
- Scallion (Bunching Onion)
- Scarlet Runner Bean
- Serrano Pepper
- Shiso (Japanese Basil)
- Snapdragon
- Summer Savory
- Sunflower
- Sweet Corn
- Thai Basil
- Tomatillo
- Tomato
- Vinca (Madagascar Periwinkle)
- Watermelon
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans every two weeks for a continuous harvest throughout summer.
- Mulch around established tomato and pepper plants to retain moisture as soil temperatures rise.
- Prune dead or diseased foliage from Brassicas like Brussels Sprouts and Kale to improve air circulation.
Pest & disease watch
- Watch closely for aphids on new growth of basil, beans, and tomatoes as temperatures climb above 60°F.
- Monitor brassicas like Brussels sprouts and cabbage for early flea beetle damage which can appear even before full summer heat.
- Check seedling sunflowers and cosmos for spider mites that thrive in Denver's dry, windy conditions.
Watering this week
Water deeply in the morning to encourage strong root growth while minimizing fungal disease risk.
Pinch back the tips of young Bush Bean plants if they are leggy to encourage bushier, more productive growth.
Denver gardening questions
3Can I finally transplant my tomato and pepper seedlings outside this week?
Yes, provided there is no threat of a drop below 50°F overnight after the average last frost date. Ensure your plants are hardened off for a few days to handle Denver's intense afternoon sun before they hit full exposure.
What vegetables can I plant directly in the ground right now?
This is an ideal time to sow bush beans, cucumbers, okra, and watermelon seeds directly into the soil. These warm-season crops will struggle if started indoors or transplanted too early due to their sensitivity to cold roots.
When should I expect my first major harvest from the current season's plants?
You can begin picking ripe tomatoes, peppers like jalapeño and poblanos, and beans soon as they mature. Keep harvesting regularly to encourage continued production throughout the summer growing window.
Other cities in zone 6a
12See the full zone 6a guide → · Plan your Denver garden in SproutGuide →