Artichoke (Cynara cardunculus var. scolymus)

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Globe artichoke is a domesticated variety of the wild cardoon (Cynara cardunculus), which is native to the Mediterranean area. Varieties of artichokes were cultivated in Sicily in the classical period of the ancient Greeks and presumably further improved in the medieval period in Muslin Spain and the Maghreb. They are grown for their immature inflorescence – flower buds consumed before the flowers come into bloom – and are known to attract wildlife, especially bees.

Artichoke has interesting nutritional characteristics related to its high content of phenolic compounds, flavonoids, inulin, fiber, and mineral salts. It has become important as a medicinal herb in recent years following the discovery of cynarine. This bitter-tasting compound, which is found in the leaves, improves liver and gall bladder function, stimulates the secretion of digestive juices, especially bile, and lowers blood cholesterol levels.

Growing recommendations

Artichoke plants are short-lived perennials in warmers climates but are normally grown as annuals in cooler regions. The plants do not survive temperatures below -7° C. They can be grown in a fertile, well-drained light (sandy), medium (loamy), or heavy (clay) soil, preferring a rather neutral pH (6.5-7.5), and tolerate saline conditions. Artichokes will usually do best in open locations, in full sun or partial shade, and are reasonable wind resistant. They are commonly propagated vegetatively by division of the suckers. Flowering occur each spring after the plants are well established.

Artichokes can be started from seed indoors in late winter, where they will germinate within 10 days at an optimum temperature of 24° C. Note that the seedlings will be to be hardened off before planting them outside, as artichokes need to experience a slight chilling before they will set buds. This can be done by putting the plants out in mid-spring and exposing them for a week to temperatures of about 10° C. Once outside, the plants should be thinned to 1.50 m. Good drainage of the soil is crucial to prevent the roots from rotting, especially in areas where they will be overwintered.

Common diseases and pests

• Viral diseases: Artichoke curly dwarf virus (ACDV)
• Bacterial diseases: Bacterial crown rot (Erwinia chrysanthemi)
• Fungal diseases: Botrytis rot/gray mold (Botrytis cinerea)
• Insect pests: Armyworms (beet armyworm, yellow striped armyworm) (Spodoptera exigua, Spodoptera ornithogalli), artichoke aphid (Capitophorus elaeagni), artichoke plume moth (Platyptilia carduidactyla), flea beetle (palestriped flea beetle) (Systena blanda), loopers (cabbage looper, alfalfa looper) (Trichoplusia ni), spider mites (two-spotted spider mite) (Tetranychus urticae).

Pollination, crossing, and isolation

Artichokes possess individual florets combined into a bluish-purple capitulum. While hermaphrodite, they are self-sterile, with their anthers releasing pollen five days before the stigmas are receptive to the pollen. However, some of the stigmas can be receptive to the pollen that is being released at any given time. Each floret has the ability to be pollinated by insects with pollen from a second floret located on the same capitulum or another one.

Note that artichokes do not usually come true from seed and will produce offsprings that may vary greatly from the original plant. Plants are instead vegetatively propagated with, however, inbred individuals suffering from inbreeding depression that is often expressed in lower vigor.

To prevent crossing with other artichokes varieties and cardoons, each individual floret can be isolated by covering them with a bag. They will need to be shaken once a day to ensure that the pollen travels down the style and pollinates the ovule. The capitula are cut when they are fully open and exhibit their white seed plumes.

General seed saving guidelines (harvesting and processing)

The harvested capitula can be dry away from sunlight and finish maturing in a protected location. Once they are completely dry, those can be placed inside a bag and strongly beaten with a stick. This will release and separate the seeds from the rest of the flower head, allowing the seeds to be processed easily. They can also be separated by hands (wearing gloves) by rubbing each capitulum over a bowl. Larger debris are removed manually while the remaining chaff is winnowed.

Artichoke seeds will remain viable for an average of seven years when stored under optimum conditions.