How long does st. john's wort take to grow?

St. John's Wort is ready to harvest in about 120 days, measured from planting.

When to Plant St. John's Wort

Plant st. john's wort by your frost dates, not the calendar: start seeds indoors about 8 weeks before your last spring frost, then plant outdoors about 2 weeks after your last frost. Pick your USDA zone below for exact dates.

St. John's Wort planting calendar

🌱

Start seeds indoors

Feb 18

🌿

Transplant outdoors

Apr 29

🌾

Projected first harvest

Aug 27

JJan

FFeb

MMar

AApr

MMay

JJun

JJul

AAug

SSep

OOct

NNov

DDec

🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 7a — approximate

St. John's Wort is ready to harvest in about 120 days. Dates above use zone 7 as a reference point. Pick your zone below, or 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.

St. John's Wort →

Common problems with st. john's wort

What to watch for, with identification and treatment for each

Four-Lined Plant Bug Common Stalk Borer Groundhogs Ants Aphids Armyworms Anthracnose Damping-Off Frost & Cold Injury Gray Mold Herbicide Injury Mosaic Virus

🌱 Grow st. john's wort with a calendar built for your exact yard

HomeSown turns your ZIP code into a personalized planting calendar, watering reminders, and pest help. Free to start.

Start your free garden →

When to plant st. john's wort in your zone

Zone 3 →Zone 4 →Zone 5 →Zone 6 →Zone 7 →Zone 8 →Zone 9 →Zone 10 →