When to Plant Spinach in Colorado
Colorado spans USDA hardiness 4a to 7a (zones 4a to 7a on this page). Plant spinach 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
Spinach planting calendar for Colorado, Zone 4a
Average last spring frost
May 15
Average first fall frost
September 20
spring planting
Start seeds indoors
Mar 13
Transplant outdoors
Apr 17
Projected first harvest
May 29
fall planting
Direct sow
Aug 16
Projected first harvest
Sep 27
spring planting
fall planting
Most spinach mature in about 41 to 45 days depending on the variety. Full zone 4 guide (both 4a and 4b) →
Spinach planting calendar for Colorado, Zone 4b
Average last spring frost
May 10
Average first fall frost
September 25
spring planting
Start seeds indoors
Mar 8
Transplant outdoors
Apr 12
Projected first harvest
May 24
fall planting
Direct sow
Aug 21
Projected first harvest
Oct 2
spring planting
fall planting
Most spinach mature in about 41 to 45 days depending on the variety. Full zone 4 guide (both 4a and 4b) →
Spinach planting calendar for Colorado, Zone 5a
Average last spring frost
May 5
Average first fall frost
October 1
spring planting
Start seeds indoors
Mar 3
Transplant outdoors
Apr 7
Projected first harvest
May 19
fall planting
Direct sow
Aug 27
Projected first harvest
Oct 8
spring planting
fall planting
Most spinach mature in about 41 to 45 days depending on the variety. Full zone 5 guide (both 5a and 5b) →
Spinach planting calendar for Colorado, Zone 5b
Average last spring frost
April 30
Average first fall frost
October 5
spring planting
Start seeds indoors
Feb 26
Transplant outdoors
Apr 2
Projected first harvest
May 14
fall planting
Direct sow
Aug 31
Projected first harvest
Oct 12
spring planting
fall planting
Most spinach mature in about 41 to 45 days depending on the variety. Full zone 5 guide (both 5a and 5b) →
Spinach planting calendar for Colorado, Zone 6a
Average last spring frost
April 25
Average first fall frost
October 10
spring planting
Start seeds indoors
Feb 21
Transplant outdoors
Mar 28
Projected first harvest
May 9
fall planting
Direct sow
Sep 5
Projected first harvest
Oct 17
spring planting
fall planting
Most spinach mature in about 41 to 45 days depending on the variety. Full zone 6 guide (both 6a and 6b) →
Spinach planting calendar for Colorado, Zone 6b
Average last spring frost
April 20
Average first fall frost
October 15
spring planting
Start seeds indoors
Feb 16
Transplant outdoors
Mar 23
Projected first harvest
May 4
fall planting
Direct sow
Sep 10
Projected first harvest
Oct 22
spring planting
fall planting
Most spinach mature in about 41 to 45 days depending on the variety. Full zone 6 guide (both 6a and 6b) →
Spinach planting calendar for Colorado, Zone 7a
Average last spring frost
April 15
Average first fall frost
October 20
spring planting
Start seeds indoors
Feb 11
Transplant outdoors
Mar 18
Projected first harvest
Apr 29
fall planting
Direct sow
Sep 15
Projected first harvest
Oct 27
spring planting
fall planting
Most spinach mature in about 41 to 45 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
3 varieties of spinach in the HomeSown library. Tap any for its full grow guide.
Common problems with spinach
What to watch for, with identification and treatment for each
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