Vegetable · Asteraceae
Cardoon
Cynara cardunculus
Hand it a long season, rich soil, and a few weeks of blanching, and you'll get tender stalks no market bothers to stock.
Full sun
Every 3–7 days
120–150 days
USDA 7–10
Overview
Cardoon's basically a giant silver thistle in the daisy family. It's the same species as the globe artichoke, but instead of going for the buds, you're after the blanched leaf stalks and midribs. They cook up tender with a soft artichoke taste, and folks around the Mediterranean have been growing it in their gardens for centuries.
Here's the thing, it's big. A grown plant gets to 4 to nearly 4 to 6.5 feet (119 to 201 cm) and throws out arching, deeply cut leaves on spiny stalks, so it earns a spot in the bed before you even harvest. Give it full sun, some room, and steady food, and it'll grow fast and look great while it does.
So what's the catch? Just the long wait and the blanching. Cardoon needs 120 to 150 days to fill out, and the stalks go bitter and stringy unless you wrap them up in the dark for a few weeks first. Skip that and you've swapped a real treat for something tough and woody, which would be a shame.
Care
The short version: full sun, deep and steady moisture, and rich, well-drained soil, plus a generous feed all season and a few weeks of blanching before you cut the stalks.
Light
Cardoon really wants full sun, a spot that soaks up direct light most of the day. It'll put up with a bit of partial shade, but the stalks come in thinner and the plant just doesn't grow as strongly, so give it the brightest place you've got.
Water
Keep things deep and evenly moist all through active growth, because dry spells are what make the stalks tough and stringy. Watering every 3 to 7 days usually does it, a little more when it's hot, but don't let the ground sit soggy or you'll rot the crown.
Soil
Get it into deep, fertile, well-drained loam that you've mixed full of compost or aged manure. A pH of 6.0 to 7.0 is what it likes, and loose, rich ground lets those big roots spread out while keeping all that hungry top growth fed.
Temperature
Cardoon's happy across a wide range, roughly 32°F to 86°F (0°C to 30°C), and it takes real heat in stride. A hard frost is another story though, since it'll knock the stalks down, which is exactly why you bring the crop in before the deep cold arrives.
Humidity
Regular outdoor humidity, somewhere around 40% to 70%, is all it's after, so there's nothing to fuss over there. What really counts is good airflow, because crowded, damp leaves are an open invitation to aphids and powdery mildew.
Feeding
This one's a big eater. Work plenty of compost or aged manure into the bed when you plant, then hand it a balanced fertilizer about once a month through spring and summer to keep all that quick growth going.
Pruning
Pull off the old, damaged, or yellowing outer leaves as the season rolls on. Then, about 3 to 4 weeks before harvest, gather the stalks and blanch them by tying and wrapping with cardboard, paper, or soil, which softens the stems and takes the bitter edge off. Growing for stalks and not for show? Just snip the flower stalks off.
Repotting
No pots to deal with here, since cardoon isn't a container plant. It grows in the ground and you usually start it from seed each year, so the only potting you'll do is bumping young seedlings into bigger cells before they go out, just so the roots don't start coiling.
Size & spacing
Plan for a big one, 4 to nearly 4 to 6.5 feet (119 to 201 cm) tall and spreading 3 to 4 feet (90 to 120 cm), and give each plant that kind of room. Spacing them out lets the air move and keeps disease from settling in, so it's worth the space.
When to plant
Cardoon's after a long warm stretch with no frost. Start the seeds indoors in late winter, pop the plants outside once the cold's gone, then blanch the stalks for 3 to 4 weeks and harvest in fall before a hard frost shows up.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 8-10 weeks before the last spring frost
- Plant: After danger of frost has passed in spring
- Harvest: Blanch stalks for about 3-4 weeks, then harvest leaf stalks/midribs in fall before hard frost
Hardiness
USDA hardiness zones: 7–10
Temperature: down to -18°C
Troubleshooting
Most cardoon hiccups turn up in the stalks or the crown, and they're not hard to spot early. Catch them in time and they won't get the chance to ruin your harvest. Find what looks familiar below, then sort it out while it still does some good.
The plant wilts and collapses with a soft, dark crown
When the crown or roots go brown, mushy, and smelly after a wet spell, that's crown or root rot from soggy ground. There's really no saving a plant this far gone, so just lift it and toss it. Fix the drainage and back off the watering before you replant, because water pooling around the crown is what kicks off the rot in the first place.
Fix:
- Remove and destroy severely affected plants
- Improve drainage and reduce watering frequency
Tough, stringy, or hollow leaf stalks
Stalks go fibrous and bitter when they're left unblanched or sit around past their prime, and shaky watering just makes them woodier. The fix is easy enough: tie and wrap them 3 to 4 weeks before you cut, keep the soil evenly moist the whole time, and harvest as soon as they soften up. Want to double-check? Slice one crosswise, because an overmature stalk turns up hollow in the middle.
Fix:
- Blanch stalks for 3-4 weeks before harvest by tying and wrapping them
- Harvest at proper maturity before stalks toughen
- Maintain even soil moisture during stalk development
Sticky residue and curled new growth on the leaves
Curled tips and a sticky film usually mean aphids have set up on the undersides and growing points, while a white dusty coating in close, humid air is powdery mildew. Blast the aphids off with a hard jet of water, and only reach for insecticidal soap if some stick around. Open the planting up so air can move and pull the worst mildewed leaves, and it'll be fine.
Fix:
- Dislodge aphids with a strong spray of water
- Apply insecticidal soap if infestation is heavy
- Improve air circulation and remove badly mildewed leaves
Toxicity
Good news on safety, cardoon's an edible vegetable with no poison for pets, livestock, or people. The only real worry is physical, since the leaves and stalks come armed with sharp spines. Just throw on some gloves whenever you handle or harvest it and you're set.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
No poisoning risk to worry about here, since cardoon isn't on the ASPCA toxic list. The only thing to keep an eye on is the sharp spines, which can prick a curious nose.
Dogs None
A dog can chew the leaves and be totally fine, because there's nothing poisonous in the plant. Honestly, the prickly leaves usually put them off well before it comes to that.
Horses Safe
Horses are in no toxic danger from cardoon at all. Most of them just leave the spiny clump alone on their own.
Rabbits Safe
Rabbits can nibble away safely, since there aren't any toxic compounds to worry about. The bristly leaves are pretty much the only thing that holds them back.
Livestock Safe
Cattle, goats, and sheep can graze it without any poisoning. It's the dense spines that tend to keep them off, not a toxin, because there isn't one.
Birds Safe
Birds face no toxic danger from cardoon whatsoever. Backyard flocks can peck at it as much as they like.
People Safe
The blanched stalks and midribs are a traditional vegetable, cooked and eaten with no harm at all. Just remember the gloves at harvest, because those spines can scratch.
The leaves and stalks bear sharp spines and prickles that can scratch or prick skin; wear gloves when handling and harvesting. This is a physical hazard, not a poisoning risk.
Varieties
Most cardoons you'll find are Italian heirlooms bred for plump, tender stalks. These are the ones worth knowing by name.
Gigante di Romagna
A big Italian heirloom that folks grow for its thick, fleshy leaf stalks.
Bianco Avorio
An ivory-white stalk type that's prized for tender, mild midribs once it's blanched.
Gobbo di Nizza Monferrato
The Piedmontese 'hunchback' cardoon, which is clever enough to blanch itself as the stalks curve down into the soil.
How to propagate
Most people just grow cardoon from seed each year, which is the simplest way to go. But if your winters are mild, you can also split an established crown to copy a plant you already like.
SeedModerate
Sow indoors 8-10 weeks before the last frost, then transplant out after frost · 120-150 days to reach harvestable maturity
Seed's the usual way to go. Start it indoors 8 to 10 weeks before your last frost and set the seedlings out once the cold's passed, since the plant needs a good 120 to 150 days to size up before you can harvest.
DivisionModerate
Spring, lifting offsets/suckers from the crown of an established plant · One growing season to establish
If your winters stay mild, here's another option: lift offsets from the crown of an established plant in spring and replant them. That way you can copy a plant you already like, and the new one gets a full growing season to settle in.
Myths
Cardoon and the globe artichoke are totally different species.
Nope, they're two takes on the same plant, Cynara cardunculus. Cardoon's grown for its blanched leaf stalks, while the globe artichoke is the very same species grown for its young flower buds instead.
Cardoon's a harmless garden ornamental no matter where you are.
Not quite, because in California and parts of Australia and Argentina it's slipped out of gardens and become an invasive noxious weed, forming dense spiny stands across rangeland. So it's worth checking whether it's a problem in your area before you plant it.