When to Plant St. John's Wort in Zone 4
In USDA zone 4a, start seeds indoors around March 20, transplant or plant outdoors May 29 to September 26, and expect your first harvest around September 26. (4a shown here — see 4a and 4b dates separately below.)
St. John's Wort planting calendar for USDA Zone 4a
Average last spring frost
May 15
Average first fall frost
September 20
Start seeds indoors
Mar 20
Transplant outdoors
May 29
Projected first harvest
Sep 26
St. John's Wort is ready to harvest in about 120 days, needing roughly 128 frost-free days in zone 4a.
St. John's Wort planting calendar for USDA Zone 4b
Average last spring frost
May 10
Average first fall frost
September 25
Start seeds indoors
Mar 15
Transplant outdoors
May 24
Projected first harvest
Sep 21
St. John's Wort is ready to harvest in about 120 days, needing roughly 138 frost-free days in zone 4b.
Not sure whether you're in 4a or 4b? Set your ZIP in HomeSown for dates tuned to your exact location.
Varieties to grow
1 variety of st. john's wort in the HomeSown library. Tap any for its full grow guide.
Common problems with st. john's wort
What to watch for, with identification and treatment for each
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