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Milk Thistle, Mary's Thistle
Silybum marianum 'Adriana'

Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Silybum (SIGH-lee-bum) (Info)
Species: marianum (mar-ee-AH-num) (Info)
Cultivar: Adriana




4-6 ft. (1.2-1.8 m)


24-36 in. (60-90 cm)


USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:

Full Sun


Plant has spines or sharp edges; use extreme caution when handling

Bloom Color:

White/Near White

Bloom Time:

Late Spring/Early Summer

Mid Summer


Grown for foliage



Other details:

May be a noxious weed or invasive

This plant is attractive to bees, butterflies and/or birds

Average Water Needs; Water regularly; do not overwater

Self-sows freely; deadhead if you do not want volunteer seedlings next season

Soil pH requirements:

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

From seed; direct sow outdoors in fall

From seed; winter sow in vented containers, coldframe or unheated greenhouse

From seed; sow indoors before last frost

From seed; direct sow after last frost

Seed Collecting:

Collect seedhead/pod when flowers fade; allow to dry

Wear gloves to protect hands when handling seeds

Properly cleaned, seed can be successfully stored


This plant has been said to grow in the following regions:

Gray, Louisiana

Eidson, Tennessee

Spring, Texas

Gardeners' Notes:


On Sep 20, 2010, GretchenA from Spring, TX wrote:

I was surprised to read here about milk thistle having no positive qualities. It is well known to be a powerful liver detoxifier and is useful for some gallbladder disorders.


On May 27, 2009, saya from Heerlen
Netherlands (Zone 8b) wrote:

Yeah.. pretty and very useful to keep unwanted visitors out of the garden. I've put paper bags over the spent flowers so it could set seeds but also to prevent sprinkling its seeds around. I've saved these sharp and spiny seedheads for the birds in my neighbours aviary. The birds loved to pick out the seeds, they were fighting about it. To remove the plants at the end of the season is a very unpleasant and nearly dangerous job.