Globe artichoke: growing from seed, vernalisation, harvest and overwintering

In brief: The globe artichoke (Cynara cardunculus var. scolymus) is a heat-loving perennial from the Mediterranean that often dies off over winter here. Sow it in February to March on a windowsill at 21–26 °C and plant it out after 15 May, 75–100 cm apart. Annual varieties produce buds in the first year if the seedlings go through about 10 days of cold at 7–10 °C.

In the bed, an artichoke looks like a giant silvery thistle. What you eat are the unopened flower buds: the fleshy lower part of the bracts and the "heart" at the base of the flower head. A fresh artichoke from your own garden is something completely different from marinated hearts from a jar, and in the garden it also holds its own as an ornamental plant.

In the Czech climate it faces two obstacles: winter, and the fact that it forms buds only after a period of cold. Both can be worked around. Below you will find how to grow an artichoke from seed so that it fruits in its first summer, how to overwinter it, and how to harvest and cook the buds.

What an artichoke is and how it differs from cardoon

The globe artichoke is a perennial of the daisy family (Asteraceae), related to thistles. It comes from the Mediterranean. It grows to 1.2–1.5 m and just as wide, with large, deeply cut, silvery-grey leaves. If you do not harvest the buds, they open into purple flowers that bees and bumblebees love.

Botanically it belongs to the same species as cardoon (Cynara cardunculus). The difference lies in what is eaten: with the artichoke it is the large buds, with cardoon the blanched leaf stalks. When buying seeds, therefore, check what is in the packet.

Why an artichoke needs cold: vernalisation

An artichoke forms buds only after it has experienced a period of cold. In the Mediterranean, winter provides it. A seedling sown in spring in the warmth, however, never gets that cold; it grows only a large leaf rosette and the buds come after winter.

The seed company Johnny's Selected Seeds states that an artichoke needs about 10 days at temperatures of 7–10 °C. Annual varieties such as Imperial Star need less cold than perennial ones. In practice you can manage this here by hardening the seedlings off outdoors in early spring: April and May nights at around 7–10 °C will give them the cold they need. Just protect them from frost, as young plants are damaged by it.

Sowing and raising seedlings step by step

1. Timing: sow from February to early March. Seedlings need 8–12 weeks before planting out.
2. Sowing: place the seeds 1–2 cm deep, ideally one per cell in a seed tray or small pots with seed-sowing compost.
3. Germination: keep the compost moist and warm, at 21–26 °C. Seeds usually germinate in 1–3 weeks.
4. Growth: after emergence, move the seedlings into the light and somewhere cooler, 15–21 °C by day and 10–15 °C at night. Of the seedlings that emerge, select the strong ones and discard the weak and pale ones.
5. Potting on: once they have 3–4 true leaves, pot them on into pots 10–12 cm in diameter.
6. Cold and hardening off: from April put the seedlings outside in a sheltered spot, and leave them out at night as long as the temperature does not fall below 5 °C. About 10 cold days will ensure bud formation later.
7. Planting out: after 15 May in a sunny, warm spot, 75–100 cm apart with 1 m between rows.

When and how to raise other vegetables on a windowsill is summarised in the article what to sow in February, and germination techniques in the article seed germination – techniques for every type of plant.

Site, soil and care during the summer

• Site: full sun, sheltered from cold wind, ideally by a south-facing wall or fence.
• Soil: deep, rich and free-draining. Work compost into heavy soil; winter waterlogging is worse for an artichoke than frost.
• Watering: regular, especially once the buds start to form. In dry spells the buds are small and tough.
• Feeding: an artichoke is a hungry plant. In spring apply compost or fertiliser, and in summer feed once every 3–4 weeks.
• Mulch: a layer of straw or grass clippings around the plant retains moisture and suppresses weeds.

The most common pests are aphids on the buds and the undersides of the leaves, and slugs on young plants. Wash aphids off with a jet of water; for slugs, regular checks at dusk are the most reliable method.

Harvest and preparation in the kitchen

Harvest the buds when they have reached full size but the bracts are still pressed tightly together. The main terminal bud ripens first, then the smaller side ones. Cut them off with a knife, together with 5–8 cm of stem. Once the bracts begin to open, the bud toughens and turns bitter.

1. Pull off the tough lower bracts and trim the tips of the others.
2. Peel the stem; it is also edible.
3. Rub the bud with lemon, otherwise it turns brown at the cut surface straight away.
4. Boil in salted water with lemon for 20–40 minutes, depending on size. It is done when an inner bract pulls out easily.
5. Eat it bract by bract: scrape the soft lower part off with your teeth and discard the rest. In the middle, remove the fuzzy choke and eat the heart.

Small side buds can also be halved, cleared of the choke and fried in a pan or preserved in oil. The artichoke belongs to the daisy family; people allergic to this family should be careful.

Overwintering an artichoke

In the Czech Republic the artichoke is not reliably frost-hardy. In warm regions it may overwinter outdoors as a short-lived perennial; elsewhere treat it more as an annual or overwinter it indoors.

• Outdoors: in autumn cut the leaves back to 20–30 cm, cover the base of the plant with dry leaves or straw, add evergreen branches and, for frosts, horticultural fleece. The main danger is wet, not just frost.
• Indoors: before the frosts, lift the plant with its root ball, cut back the leaves and store it in a box with slightly damp sand in a frost-free cellar. Return it to the bed in spring.
• Rejuvenation: perennial plants crop best for 3–4 years. Then divide them in spring or take off side shoots with roots.

General advice on preparing the garden for winter can be found in the article important tips for winterising the garden. If you like large decorative perennials, also take a look at ornamental perennials.

Why an artichoke has no buds

Frequently asked questions

Can an artichoke be grown in the Czech Republic?

Yes. The simplest approach is to grow it as an annual: sow in February, give it a short spell of cold while hardening off, and plant out after the last frosts. In warm regions it may even overwinter with protection.

When should artichokes be sown?

In February to early March on a windowsill. Seedlings need 8–12 weeks before you plant them out after 15 May.

When should artichokes be harvested?

When the bud has reached full size and the bracts are still tightly closed; when grown as an annual, usually from July to September. A bud that is starting to open is tough.

Does an artichoke survive the winter outdoors?

Reliably only in warm regions, in free-draining soil with good cover. Elsewhere, lift it for the winter and store it in a frost-free cellar.

Why does my artichoke not flower?

Most often it has not experienced the cold that triggers bud formation, or it is a perennial variety sown in spring. Such a plant forms buds only in its second year.

Recommended products

We do not currently stock artichoke seeds. The following are useful for growing it:

• Seed-sowing compost 5 l – for February sowing into seed trays.
• Peat pot 8 cm with a notch – for potting on seedlings; the seedlings are then planted out together with the pot.
• Fleece 1.6 × 5 m for early harvests, white – protects hardened-off seedlings from night frost and serves as a winter cover.
• Hoštice fertiliser 1 kg – an organic fertiliser for demanding fruiting vegetables.

Sources

• Globe artichokes: grow your own – sowing, spacing, harvest, winter protection (Royal Horticultural Society)
• Imperial Star Artichoke – germination temperature and vernalisation (Johnny's Selected Seeds)

Updated: 27 September 2026