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When to Plant Milk Thistle in Alaska

Alaska spans USDA hardiness 1a to 8b (zones 1a to 8b 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 1a · Zone 1b · Zone 2a · Zone 2b · Zone 3a · Zone 3b · Zone 4a · Zone 4b · Zone 5a · Zone 5b · Zone 6a · Zone 6b · Zone 7a · Zone 7b · Zone 8a · Zone 8b

Milk Thistle planting calendar for Alaska, Zone 1a

Average last spring frost

May 24

Average first fall frost

August 25

🌿

Direct sow

Jun 7

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 1a (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 1a typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension.

Milk Thistle planting calendar for Alaska, Zone 1b

Average last spring frost

May 29

Average first fall frost

August 28

🌿

Direct sow

Jun 12

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 1b (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 1b typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension.

Milk Thistle planting calendar for Alaska, Zone 2a

Average last spring frost

May 24

Average first fall frost

September 5

🌿

Direct sow

Jun 7

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 2a (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 2a typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension.

Milk Thistle planting calendar for Alaska, Zone 2b

Average last spring frost

May 30

Average first fall frost

September 6

🌿

Direct sow

Jun 13

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 2b (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 2b typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension.

Milk Thistle planting calendar for Alaska, Zone 3a

Average last spring frost

May 30

Average first fall frost

September 10

🌿

Direct sow

Jun 13

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 3a (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 3a typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension. Full zone 3 guide (both 3a and 3b) →

Milk Thistle planting calendar for Alaska, Zone 3b

Average last spring frost

May 20

Average first fall frost

September 15

🌿

Direct sow

Jun 3

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 3b (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 3b typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension. Full zone 3 guide (both 3a and 3b) →

Milk Thistle planting calendar for Alaska, Zone 4a

Average last spring frost

May 15

Average first fall frost

September 20

🌿

Direct sow

May 29

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 4a (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 4a typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension. Full zone 4 guide (both 4a and 4b) →

Milk Thistle planting calendar for Alaska, Zone 4b

Average last spring frost

May 10

Average first fall frost

September 25

🌿

Direct sow

May 24

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 4b (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 4b typically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension. Full zone 4 guide (both 4a and 4b) →

Milk Thistle planting calendar for Alaska, Zone 5a

Average last spring frost

May 5

Average first fall frost

October 1

🌿

Direct sow

May 19

J
F
M
A
M
J
J
A
S
O
N
D
🌱 Start indoors🌿 Growing outside🌾 HarvestTodayZone 5a (approximate)

Milk Thistle needs about 150 days to mature — longer than Zone 5a 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 Alaska, Zone 5b

Average last spring frost

April 30

Average first fall frost

October 5

🌿

Direct sow

May 14

J
F
M
A
M
J
J
A
S
O
N
D
🌱 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 Alaska, Zone 6a

Average last spring frost

April 25

Average first fall frost

October 10

🌿

Direct sow

May 9

🌾

Projected first harvest

Oct 6

J
F
M
A
M
J
J
A
S
O
N
D
🌱 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 Alaska, Zone 6b

Average last spring frost

April 20

Average first fall frost

October 15

🌿

Direct sow

May 4

🌾

Projected first harvest

Oct 1

J
F
M
A
M
J
J
A
S
O
N
D
🌱 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 Alaska, Zone 7a

Average last spring frost

April 15

Average first fall frost

October 20

🌿

Direct sow

Apr 29

🌾

Projected first harvest

Sep 26

J
F
M
A
M
J
J
A
S
O
N
D
🌱 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 Alaska, Zone 7b

Average last spring frost

April 10

Average first fall frost

October 30

🌿

Direct sow

Apr 24

🌾

Projected first harvest

Sep 21

J
F
M
A
M
J
J
A
S
O
N
D
🌱 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 Alaska, Zone 8a

Average last spring frost

April 1

Average first fall frost

November 10

🌿

Direct sow

Apr 15

🌾

Projected first harvest

Sep 12

J
F
M
A
M
J
J
A
S
O
N
D
🌱 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 Alaska, Zone 8b

Average last spring frost

March 20

Average first fall frost

November 20

🌿

Direct sow

Apr 3

🌾

Projected first harvest

Aug 31

J
F
M
A
M
J
J
A
S
O
N
D
🌱 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) →

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

🌱 Grow milk thistle with a calendar built for your exact yard

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milk thistle — full zone guide

All zonesZone 3 →Zone 4 →Zone 5 →Zone 6 →Zone 7 →Zone 8 →