Cardoon

Questions about cardoon

Does cardoon need sun or shade?

Cardoon grows in full sun (6 or more hours of direct sun a day).

It wants ordinary well-drained soil, rich in organic matter, and a good soak in dry spells. Once settled in, it stands drought.

What zones does cardoon grow in?

USDA zones 7 to 10. It is hardy to zone 7, which means it survives winter nights down to about 10 °F (−12 °C).

Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.

When does cardoon flower in my zone?

In zone 5 it flowers mid July to late August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.

Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.

How far apart should cardoon be planted?

3½ ft (100 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 4 ft (120 cm), so a group knits into one patch.

It grows 6 ft (180 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many cardoon plants do I need?

At 3½ ft apart, set out in staggered rows:

• 1 to fill 10 square feet (about 1 m²)
• 4 for a single row 10 ft (3 m) long
• 3 to fill a 4 × 8 ft bed on its own

In a mixed border, plant it as one, with clear ground around it: a feature plant is seen as an object, and a group of them is a thicket.

Is cardoon poisonous to dogs and cats?

No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.

"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.

What can I plant instead of cardoon?

Cardoon is listed as invasive in parts of North America, so the planner never uses it. These do the most similar job, and are native:

• Sweet Joe Pye weed: the same job in a bed and the same flowering time; 4 in narrower, pink, not purple.
• Hardy hibiscus: the same job in a bed; 12 in shorter, 4 in narrower.

Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.

Do deer eat cardoon?

Mostly not. NC State lists it as resistant to deer and rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.

Will cardoon spread?

It seeds itself about; the risk of it taking over is moderate. Self-seeds in mild climates. The wild form, artichoke thistle, is a listed noxious weed, invasive in grassland, in California. Cut off the flower heads before they shed seed.

It is listed as invasive in parts of North America, and the planner never chooses it.

What flowers after cardoon?

Cardoon is over by late August. These start as it finishes and carry the same spot on, so it never goes flat:

• Pink muhly grass: from mid September to early November, 3 ft tall, to stand in front of it and cover its fading stems.
• Garden chrysanthemum: from mid September to late October, 24 in tall, to stand in front of it and cover its fading stems.
• Sedum 'Autumn Joy': from mid August to mid October, 24 in tall, to stand in front of it and cover its fading stems.

What does cardoon look like in winter?

Cardoon dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.

Is cardoon good for bees and butterflies?

Cardoon is visited by pollinators, bees and butterflies.