When to Plant Milk Thistle in Oregon
Oregon spans USDA hardiness 5b to 9b (zones 5b to 9b on this page). Plant milk thistle by your local frost date, not the calendar — pick your zone below for exact start-indoors, transplant, and harvest dates.
Jump to: Zone 5b · Zone 6a · Zone 6b · Zone 7a · Zone 7b · Zone 8a · Zone 8b · Zone 9a · Zone 9b
Milk Thistle planting calendar for Oregon, Zone 5b
Average last spring frost
April 30
Average first fall frost
October 5
Direct sow
May 14
Milk Thistle needs about 150 days to mature — longer than Zone 5b typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension. Full zone 5 guide (both 5a and 5b) →
Milk Thistle planting calendar for Oregon, Zone 6a
Average last spring frost
April 25
Average first fall frost
October 10
Direct sow
May 9
Projected first harvest
Oct 6
Milk Thistle is ready to harvest in about 150 days. Full zone 6 guide (both 6a and 6b) →
Milk Thistle planting calendar for Oregon, Zone 6b
Average last spring frost
April 20
Average first fall frost
October 15
Direct sow
May 4
Projected first harvest
Oct 1
Milk Thistle is ready to harvest in about 150 days. Full zone 6 guide (both 6a and 6b) →
Milk Thistle planting calendar for Oregon, Zone 7a
Average last spring frost
April 15
Average first fall frost
October 20
Direct sow
Apr 29
Projected first harvest
Sep 26
Milk Thistle is ready to harvest in about 150 days. Full zone 7 guide (both 7a and 7b) →
Milk Thistle planting calendar for Oregon, Zone 7b
Average last spring frost
April 10
Average first fall frost
October 30
Direct sow
Apr 24
Projected first harvest
Sep 21
Milk Thistle is ready to harvest in about 150 days. Full zone 7 guide (both 7a and 7b) →
Milk Thistle planting calendar for Oregon, Zone 8a
Average last spring frost
April 1
Average first fall frost
November 10
Direct sow
Apr 15
Projected first harvest
Sep 12
Milk Thistle is ready to harvest in about 150 days. Full zone 8 guide (both 8a and 8b) →
Milk Thistle planting calendar for Oregon, Zone 8b
Average last spring frost
March 20
Average first fall frost
November 20
Direct sow
Apr 3
Projected first harvest
Aug 31
Milk Thistle is ready to harvest in about 150 days. Full zone 8 guide (both 8a and 8b) →
Milk Thistle planting calendar for Oregon, Zone 9a
Average last spring frost
March 1
Average first fall frost
December 1
Direct sow
Mar 15
Projected first harvest
Aug 12
Milk Thistle is ready to harvest in about 150 days. Full zone 9 guide (both 9a and 9b) →
Milk Thistle planting calendar for Oregon, Zone 9b
Average last spring frost
February 15
Average first fall frost
December 15
Direct sow
Mar 1
Projected first harvest
Jul 29
Milk Thistle is ready to harvest in about 150 days. Full zone 9 guide (both 9a and 9b) →
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 milk thistle in the HomeSown library. Tap any for its full grow guide.
Common problems with milk thistle
What to watch for, with identification and treatment for each
🌱 Grow milk thistle 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 →