When to Plant Zucchini in Colorado
Colorado spans USDA hardiness 4a to 7a (zones 4a to 7a on this page). Plant zucchini by your local frost date, not the calendar — pick your zone below for exact start-indoors, transplant, and harvest dates.
Jump to: Zone 4a · Zone 4b · Zone 5a · Zone 5b · Zone 6a · Zone 6b · Zone 7a
Zucchini planting calendar for Colorado, Zone 4a
Average last spring frost
May 15
Average first fall frost
September 20
Start seeds indoors
Apr 24
Transplant outdoors
May 29
Projected first harvest
Jul 23
Most zucchini mature in about 50 to 55 days depending on the variety. Full zone 4 guide (both 4a and 4b) →
Zucchini planting calendar for Colorado, Zone 4b
Average last spring frost
May 10
Average first fall frost
September 25
Start seeds indoors
Apr 19
Transplant outdoors
May 24
Projected first harvest
Jul 18
Most zucchini mature in about 50 to 55 days depending on the variety. Full zone 4 guide (both 4a and 4b) →
Zucchini planting calendar for Colorado, Zone 5a
Average last spring frost
May 5
Average first fall frost
October 1
Start seeds indoors
Apr 14
Transplant outdoors
May 19
Projected first harvest
Jul 13
Most zucchini mature in about 50 to 55 days depending on the variety. Full zone 5 guide (both 5a and 5b) →
Zucchini planting calendar for Colorado, Zone 5b
Average last spring frost
April 30
Average first fall frost
October 5
Start seeds indoors
Apr 9
Transplant outdoors
May 14
Projected first harvest
Jul 8
Most zucchini mature in about 50 to 55 days depending on the variety. Full zone 5 guide (both 5a and 5b) →
Zucchini planting calendar for Colorado, Zone 6a
Average last spring frost
April 25
Average first fall frost
October 10
Start seeds indoors
Apr 4
Transplant outdoors
May 9
Projected first harvest
Jul 3
Most zucchini mature in about 50 to 55 days depending on the variety. Full zone 6 guide (both 6a and 6b) →
Zucchini planting calendar for Colorado, Zone 6b
Average last spring frost
April 20
Average first fall frost
October 15
Start seeds indoors
Mar 30
Transplant outdoors
May 4
Projected first harvest
Jun 28
Most zucchini mature in about 50 to 55 days depending on the variety. Full zone 6 guide (both 6a and 6b) →
Zucchini planting calendar for Colorado, Zone 7a
Average last spring frost
April 15
Average first fall frost
October 20
Start seeds indoors
Mar 25
Transplant outdoors
Apr 29
Projected first harvest
Jun 23
Most zucchini mature in about 50 to 55 days depending on the variety. Full zone 7 guide (both 7a and 7b) →
Not sure which half-zone you're in? Set your ZIP in HomeSown for dates tuned to your exact location.
Varieties to grow
2 varieties of zucchini in the HomeSown library. Tap any for its full grow guide.
Common problems with zucchini
What to watch for, with identification and treatment for each
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