City · Denver
Denver planting calendar
Denver is zone 5–6 at about 1,600 m: a short, intense season between a mid-May last frost and a late-September first frost. Late snow, hail and dry wind are the local hazards, so row cover and windbreaks earn their place.
Zone5–6
FrostLast frost mid-May · first frost late September
ClimateHumid continental
RegionUS Northeast
Months12
| Month | Sow | Plant out | Tend / harvest |
|---|---|---|---|
| Jan | Onion and leek indoors | Nothing | Plan, order seed, prune dormant trees |
| Feb | Celery and onion indoors | Nothing | Chit potatoes, soil test, repair tools |
| Mar | Tomato and pepper indoors | Peas and spinach outdoors | Row cover, wind protection |
| Apr | Beet, carrot and lettuce outdoors | Broccoli, cabbage and potatoes | Harden off; watch for late snow |
| May | Bean, corn and squash after the last frost | Tomato and pepper late in the month | Last frost mid-May; mulch and set supports |
| Jun | Succession lettuce and beans | Cucumber and melon | Water, hail protection, weed |
| Jul | Autumn kale and radish | Late cabbage | Harvest, water, mulch |
| Aug | Spinach, radish and cover crop | Garlic and bulbs | Harvest, compost, save seed |
| Sep | Cover crop | Trees, shrubs and bulbs | First frost late in the month; harvest squash |
| Oct | Nothing | Bare-root trees | Mulch, protect, clean up |
| Nov | Nothing | Dormant trees | Prune, plan, repair structures |
| Dec | Microgreens indoors | Dormant trees | Order seed, service tools |
How to use it. Start with the frost line, not the month name. If your last frost is earlier or later than the one above, shift the spring rows by the same number of weeks. Soil temperature matters more than the date for warm-season crops.
What this calendar assumes
- An open, sunny bed with drainage; shade and wet soil shift every row.
- Typical frost dates for the zone or city, not a specific garden's microclimate.
- Seed and transplant dates for a home garden, not commercial scheduling.
- No heated greenhouse; a polytunnel or conservatory buys two to four weeks at each end.
Check locally
NOAA climate data · USDA NRCS soils. For the US, the USDA Plant Hardiness Zone Map is the zone reference; your state extension service has frost normals for your county.
Related
Horticulture in US Northeast · all calendars · plant spacing chart · soil calculator