When to Plant St. John's Wort in New Hampshire
New Hampshire spans USDA hardiness 4a to 6b (zones 4a to 6b on this page). Plant st. john's wort 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
St. John's Wort planting calendar for New Hampshire, 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. Full zone 4 guide (both 4a and 4b) →
St. John's Wort planting calendar for New Hampshire, 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. Full zone 4 guide (both 4a and 4b) →
St. John's Wort planting calendar for New Hampshire, Zone 5a
Average last spring frost
May 5
Average first fall frost
October 1
Start seeds indoors
Mar 10
Transplant outdoors
May 19
Projected first harvest
Sep 16
St. John's Wort is ready to harvest in about 120 days. Full zone 5 guide (both 5a and 5b) →
St. John's Wort planting calendar for New Hampshire, Zone 5b
Average last spring frost
April 30
Average first fall frost
October 5
Start seeds indoors
Mar 5
Transplant outdoors
May 14
Projected first harvest
Sep 11
St. John's Wort is ready to harvest in about 120 days. Full zone 5 guide (both 5a and 5b) →
St. John's Wort planting calendar for New Hampshire, Zone 6a
Average last spring frost
April 25
Average first fall frost
October 10
Start seeds indoors
Feb 28
Transplant outdoors
May 9
Projected first harvest
Sep 6
St. John's Wort is ready to harvest in about 120 days. Full zone 6 guide (both 6a and 6b) →
St. John's Wort planting calendar for New Hampshire, Zone 6b
Average last spring frost
April 20
Average first fall frost
October 15
Start seeds indoors
Feb 23
Transplant outdoors
May 4
Projected first harvest
Sep 1
St. John's Wort is ready to harvest in about 120 days. Full zone 6 guide (both 6a and 6b) →
Not sure which half-zone you're in? 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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