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When to Plant Milk Thistle in California

California spans USDA hardiness 5b to 11a (zones 5b to 11a 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 · Zone 10a · Zone 10b · Zone 11a

Milk Thistle planting calendar for California, Zone 5b

Average last spring frost

April 30

Average first fall frost

October 5

🌿

Direct sow

May 14

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🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 5b (approximate)

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 California, Zone 6a

Average last spring frost

April 25

Average first fall frost

October 10

🌿

Direct sow

May 9

🌾

Projected first harvest

Oct 6

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🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 6a (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 6 guide (both 6a and 6b) →

Milk Thistle planting calendar for California, Zone 6b

Average last spring frost

April 20

Average first fall frost

October 15

🌿

Direct sow

May 4

🌾

Projected first harvest

Oct 1

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🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 6b (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 6 guide (both 6a and 6b) →

Milk Thistle planting calendar for California, Zone 7a

Average last spring frost

April 15

Average first fall frost

October 20

🌿

Direct sow

Apr 29

🌾

Projected first harvest

Sep 26

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🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 7a (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 7 guide (both 7a and 7b) →

Milk Thistle planting calendar for California, Zone 7b

Average last spring frost

April 10

Average first fall frost

October 30

🌿

Direct sow

Apr 24

🌾

Projected first harvest

Sep 21

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🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 7b (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 7 guide (both 7a and 7b) →

Milk Thistle planting calendar for California, Zone 8a

Average last spring frost

April 1

Average first fall frost

November 10

🌿

Direct sow

Apr 15

🌾

Projected first harvest

Sep 12

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🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 8a (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 8 guide (both 8a and 8b) →

Milk Thistle planting calendar for California, Zone 8b

Average last spring frost

March 20

Average first fall frost

November 20

🌿

Direct sow

Apr 3

🌾

Projected first harvest

Aug 31

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🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 8b (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 8 guide (both 8a and 8b) →

Milk Thistle planting calendar for California, Zone 9a

Average last spring frost

March 1

Average first fall frost

December 1

🌿

Direct sow

Mar 15

🌾

Projected first harvest

Aug 12

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🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 9a (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 9 guide (both 9a and 9b) →

Milk Thistle planting calendar for California, Zone 9b

Average last spring frost

February 15

Average first fall frost

December 15

🌿

Direct sow

Mar 1

🌾

Projected first harvest

Jul 29

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F
M
A
M
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J
A
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O
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D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 9b (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 9 guide (both 9a and 9b) →

Milk Thistle planting calendar for California, Zone 10a

Average last spring frost

January 30

Average first fall frost

December 30

🌿

Direct sow

Feb 13

🌾

Projected first harvest

Jul 13

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F
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A
M
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D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 10a (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 10 guide (both 10a and 10b) →

Milk Thistle planting calendar for California, Zone 10b

Average last spring frost

January 30

Average first fall frost

December 30

🌿

Direct sow

Feb 13

🌾

Projected first harvest

Jul 13

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 10b (approximate)

Milk Thistle is ready to harvest in about 150 days. Full zone 10 guide (both 10a and 10b) →

Milk Thistle planting calendar for California, Zone 11a

Zone 11a doesn't get a seasonal frost — milk thistle plants on a warm/cool-season calendar instead of frost dates.

🗓️

Best planting window

Year-round

🌾

Time to harvest

~150 days

🌴 Your zone never frosts, so planting is timed to the cooler vs. warmer seasons rather than a frost date.

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🌿 Planting windowTodayZone 11a: frost-free; timed to seasons, not frost

Milk Thistle is ready to harvest in about 150 days.

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.

Milk Thistle →

Common problems with milk thistle

What to watch for, with identification and treatment for each

Four-Lined Plant BugCommon Stalk BorerGroundhogsAntsAphidsArmywormsAnthracnoseDamping-OffFrost & Cold InjuryGray MoldHerbicide InjuryMosaic Virus

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milk thistle — full zone guide

All zonesZone 5 →Zone 6 →Zone 7 →Zone 8 →Zone 9 →Zone 10 →