Planting calendar
April Planting Guide for Denver, CO: Raised Beds, Containers & In-Ground
April is an ideal month to start planting cool-season crops in Denver, CO. You can sow hardy vegetables directly in raised beds, containers, or in-ground gardens while starting warm-season plants indoors for transplant later. Focus on frost-tolerant greens and root vegetables now, and prepare for warmer crops as the month progresses.
Plant now (quick list)
spinach, kale, lettuce, radishes, carrots, peas, beets, broccoli
Plant now
- spinach
- kale
- lettuce
- radishes
- carrots
- peas
- beets
- broccoli
- cauliflower
- onions (sets or seedlings)
Start indoors
- tomatoes
- peppers
- eggplants
- basil
- cilantro
- cucumbers
- melons
- zucchini
- pumpkins
- squash
Avoid
- corn (too early for direct sow)
- beans (wait until soil warms)
- sweet potatoes
- tender herbs like basil outdoors
- warm-season flowers (too cold)
- cucumbers outdoors (wait for warmer soil)
- tomatoes outdoors (risk of frost)
- peppers outdoors
- eggplants outdoors
- pumpkins outdoors
Next 2 weeks
- harden off indoor seedlings by gradually exposing them outdoors
- direct sow beans and corn once soil reaches 60°F
- continue planting cool-season crops like lettuce and spinach
- monitor soil moisture and avoid waterlogging
- apply mulch to protect young plants from late frosts
- thin seedlings to proper spacing
- start preparing soil for warm-season crops
- watch for pests like aphids and flea beetles
- fertilize leafy greens with nitrogen-rich feed
- prune and maintain early spring perennials
FAQs
Can I plant tomatoes outdoors in Denver in April?
No, tomatoes are sensitive to frost. Start them indoors in April and transplant after the last frost, typically in late May.
What vegetables grow best in raised beds in April?
Cool-season crops like spinach, kale, lettuce, radishes, and carrots thrive in raised beds during April.
How do I protect seedlings from late frosts?
Use row covers, cloches, or cold frames to shield young plants during cold nights.
When should I start hardening off indoor seedlings?
Begin hardening off seedlings about two weeks before transplanting by gradually exposing them to outdoor conditions.
Is it better to plant peas in containers or in-ground?
Peas do well in both containers and in-ground beds as long as they have support and cool temperatures.
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