Yellow Hardhead, Bighead Knapweed, Giant Knapweed, Armenian Basketflower, Lemon Fluff Knapweed
Centaurea macrocephala

Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Centaurea (sen-TAR-ee-uh) (Info)
Species: macrocephala (mak-roh-SEF-uh-luh) (Info)

Category:

Perennials

Height:

36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 m)

Spacing:

18-24 in. (45-60 cm)

Hardiness:

USDA Zone 3a: to -39.9 C (-40 F)

USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

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

Danger:

Parts of plant are poisonous if ingested

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

Pollen may cause allergic reaction

Bloom Color:

Bright Yellow

Bloom Time:

Late Summer/Early Fall

Foliage:

Herbaceous

Other details:

May be a noxious weed or invasive

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

Drought-tolerant; suitable for xeriscaping

Average Water Needs; Water regularly; do not overwater

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

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:

Non-patented

Propagation Methods:

From seed; sow indoors before last frost

From seed; direct sow after last frost

Seed Collecting:

Allow seedheads to dry on plants; remove and collect seeds

Regional

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

Juneau, Alaska

Menifee, California

Kiowa, Colorado

Parker, Colorado

Hayden, Idaho

Chicago, Illinois

Greenville, Indiana

Barbourville, Kentucky

Mason, Michigan

Pinconning, Michigan

Hackensack, Minnesota

Minneapolis, Minnesota

Rosemount, Minnesota

Saint Cloud, Minnesota

Mathiston, Mississippi

Munsonville, New Hampshire

Hilton, New York

Ithaca, New York

Syracuse, New York

Wallkill, New York

Brinkhaven, Ohio

Columbus, Ohio

Patriot, Ohio

Westerville, Ohio

Albion, Pennsylvania

Norristown, Pennsylvania

Wilkes Barre, Pennsylvania

Kalama, Washington

Olympia, Washington

Spokane, Washington

show all

Gardeners' Notes:

3
positives
2
neutrals
1
negative
RatingContent
Negative

On Aug 24, 2013, pookha from edmonton
Canada wrote:

This species has been classified as a prohibited noxious weed by the Alberta Government
Please check your province/state

Positive

On Aug 4, 2010, kobwebz from columbia, TN (Zone 7a) wrote:

have had this for years, love the flower head,It's even self sowed a few times.

Positive

On Mar 14, 2005, lmelling from Ithaca, NY (Zone 5b) wrote:

I grow these flowers for use in dried arrangements. The "basket weave" pods look wonderful, with or without the flower still showing in the top.

I had about 10 of these plants in an area that was normal to dry in full sun. They grew wonderfully until we had two "wet" years in a row. Our ground literally has not dried out for about 2 years...Unbeknownst to us a chipmunk had dug a hole from a culvert in back of this hillside garden, which allowed water to divert into the garden itself and came out just below where these plants were. Because of the water load the whole area became saturated and killed every one of the Centaurea's. I also lost two very large Centaurea's in another garden when the water table rose.

Make sure to plant these where you can be su... read more

Positive

On Aug 3, 2004, llebpmac_bob from Zephyr
Canada wrote:

My plant is in it's second year and now has over a dozen flowers. the leaves are not particularly attractive but it's well worth it for the flowers, which are a lovely clear lemon yellow.
The buds are also very interesting, even if you have to get close to the plants to appreciate them.
Of course it's a bit over three feet tall so you need a fair bit of space to enjoy this plant.

Neutral

On Aug 31, 2002, Weezingreens from Seward, AK (Zone 3b) wrote:

I was attracted to this plant when I saw it in a seed catalog under the name 'Armenian Basket Flower', probably due to the unusual pattern of the bud and flower base. The plants survived the winter, but have not thrived in the less than fertile spot where they reside. I have, however, seen them doing quite well in another garden in our small Alaskan town.

One should use caution when introducing this plant to the garden. It is considered a noxious weed in Washington state, and others, I'm sure. One might be well-served to clip the spent flower heads if this plant thrives in your area, so as not to introduce it to the wild.

Neutral

On Nov 2, 2001, poppysue from Westbrook, ME (Zone 5a) wrote:

This bold perennial adds an informal touch to the garden. The foliage is course, and strong stems support the large 3-4 inch flowers. The yellow thistle-like blooms can reach a height of 4 feet and the scaly base below the petals adds an interesting touch. This is an excellent plant for the back of the border, and will attract loads of butterflies. It prefers a sunny location and well-drained soil. Its hardy from zones 9-3 and quite tolerant of dry conditions