What to plant this week in Denver, CO
Denver gardeners are currently in the critical transition window where late spring frosts can still damage tender crops, but the long growing season is kicking into high gear. This week marks the final push to harden off transplants before the average last frost date of April 21, ensuring your harvests for basil, beans, and melons start strong.
The next 7 days
Denver, COGrowing in Denver right now
- Protect young plants with row covers immediately if overnight temps dip near the -10°F zone minimum or approach freezing, as dry air accelerates cold damage on foliage. Take advantage of Denver's intense afternoon sun by using shade cloth now to prevent bolting in warm-weather crops like okra and sweet corn before harvest.
- Address local soil compaction common in the Front Range by incorporating organic matter before planting; sandy-loam textures here drain quickly but require extra moisture retention for newly sown beans and cucumbers. Monitor watering closely during this dry spring period to ensure deep root establishment in our fast-draining soils.
- Time your harvest of early bush beans and zucchini carefully now that temperatures have risen past the frost danger, utilizing the 107+ day window before the first fall freeze on October 17.
Sow this week
No direct sowing windows open this week.
Transplant this week
Nothing is due to go out this week.
Harvest soon
41 crops- Basil
- Borage
- Bush Bean
- Cantaloupe
- Celery
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dahlia
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Ghost Pepper (Bhut Jolokia)
- Gourd (Ornamental/Bottle)
- Honeydew Melon
- Lima Bean
- Lisianthus (Prairie Gentian)
- Loofah (Luffa)
- Malabar Spinach
- Nasturtium
- Okra
- Pole Bean
- Pumpkin
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Sweet Potato
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow bush beans and sweet corn every two weeks for continuous harvests through summer.
- Pinch back the tops of zucchini and squash plants now to encourage more fruit development rather than just vines.
- Cut back dying foliage on basil and borage after heavy harvesting to promote a second, smaller flush of growth.
Pest & disease watch
- Watch for aphid colonies forming on the undersides of newly transplanted leafy greens and basil as humidity levels fluctuate in early spring.
- Check cucumber and squash plants for early signs of powdery mildew, which thrives in the dry Denver air when overhead watering is practiced. Scout for spider mites on delicate flowers like cosmos and zinnias before populations explode with rising temperatures.
Watering this week
Water deeply in the early morning to reduce evaporation while supporting heavy fruit production on melons and squash.
Pull any volunteer weeds immediately around your transplants like edamame and fennel before they compete for nutrients.
Denver gardening questions
3Can I plant garlic bulbs this week despite the frost dates?
Yes, if you missed the ideal fall planting window, early spring garlic can still be set in the ground now to develop roots for summer harvest. However, ensure the soil is workable and not soggy given Denver's rapid thaw patterns.
When should I start harvesting my first bush beans?
You can begin picking pods of your Bush Bean variety as soon as they reach 2-3 inches in length, usually 50 to 60 days after transplanting in our zone 6a climate. Pick frequently to encourage continued production through the long summer.
Are there specific pest risks for my Ghost Pepper plants right now?
While the Ghost Pepper plant itself is resilient, watch for spider mites and whiteflies which can stress the foliage before the heavy fruiting period sets in. A strong spray of water or neem oil can keep these early-season pests at bay.
Other cities in zone 6a
12See the full zone 6a guide → · Plan your Denver garden in SproutGuide →