The artichoke is a cultivated thistle grown for its edible flower buds, which are either green or purple and must be harvested before the flower begins to bloom. Plants are mostly perennial, although some types can be grown as annuals, and will reach 2–7′ tall with silvery to green leaves. Flower buds grow 3–6″ in diameter with spiny scales. Both the base of the bud and the fleshy lower half of each scale can be eaten. Plants will produce numerous buds, particularly if harvested regularly.
Imperial Star is a green artichoke that is well adapted for annual growing in a wide variety of climates. When grown from seed, it will produce artichokes in its first year. It can also be grown as a perennial in USDA Zones 7 and warmer. Plants are spreading and grow to between 2 and 3 feet tall, producing 1–2 large, edible primary flower buds of 3–4″ diameter and several smaller secondary buds. The buds are nearly spineless and globe-shaped with tight scales when ready for harvest. The leaves are large and rich silvery-green in color. If you do not harvest all of the buds for eating, they will bloom into 6–8″ purple thistle-like flowers.
Seed Depth: 1/4″
Space Between Plants: 2–6′
Space Between Rows: 3–4′
Germination Soil Temperature: 60–80°F
Days for Germination: 10–15
Sow Indoors: 6–10 weeks before average last spring frost.
Sow Outdoors: Not recommended. After average last frost date in areas with long growing season.
Vegetative: Can be propagated by dividing mature plants. Plants will produce rooted shoots near their base, known as offsets or suckers, which can be carefully removed from the main plant and replanted in a new location. The best time for this is in early fall, in order to allow time for establishment before winter, or in early spring. Plants grown this way will produce more quickly and bountifully.
You can also buy artichoke crowns or dormant roots. These are planted directly into the soil.
Grown as an annual in climate zones below USDA Zone 7 or as a perennial in Zones 7–11. Artichokes are best suited to humid climates with cool days and nights and mild winters. However, the Imperial Star variety is more adaptable than other types, allowing almost anyone anywhere to grow fresh artichokes within a single growing season.
Natural: Full Sun.
Artificial: Young plants grow well under fluorescent lamps. Make sure to allow up to 10 hours of light per day.
Soil: Artichoke prefers fertile, loamy, or sandy soil which drains well. A pH range between 6.5–8 will keep plants healthy and nourished.
Soilless: Soilless mixes are used for starting seeds prior to transplanting.
Hydroponics: Clay pellet or other media beds will work best for artichokes.
Water: Artichokes require moderate to heavy watering to imitate the moist climate they naturally prefer. Although somewhat drought tolerant, they will have a greater yield when kept evenly moist, especially while flower buds are forming.
Nutrients: Artichokes require a high level of nutrients.
When planting or transplanting, add well-rotted composted manure or a complete organic fertilizer. Artichokes should be fed every 2–3 weeks during active growth periods, using fish emulsion, compost tea, or a side dressing of compost and cottonseed meal around the base of the plant.
Pruning: For perennial crops, remove less vigorous plants after the first year to get a 5–6′ spacing between plants. In late fall, prune artichoke to 8–12″ above soil level to prepare for winter dormancy.
Mulching: During the growing season, keep soil mulched to help retain moisture. In late fall, after pruning plants, cover base with a layer of mulch and straw to protect artichokes from winter frosts. The plants should overwinter and send up new shoots from the root base in the spring. In extremely cold climates, cover this first layer of mulch with an inverted wooden box or barrel, and mulch over the box as well to provide extra protection.
Disease(s): Artichokes are usually disease-free.
Deficiency(s): Deficiencies can be caused by a low soil pH. To raise pH, amend with lime. The best time to add lime is in the fall or winter, when it will have a chance to break down during the plant’s dormancy. You can use dolomitic or calcitic lime as well as wood ash. Soils that are deficient in calcium will result in a reduced yield of artichokes.
Rotation: Avoid growing artichokes where you have previously grown sunflowers because they can be susceptible to the same diseases.
Companions: Marigold, yarrow, nasturtium, and Queen Anne’s Lace. These flowers will attract beneficial predatory insects.
Harvest: When flower buds have reached full size (3–4″ diameter) but before they have begun to open, cut them from the plant about 1 inch below their base. The smaller they are, the more tender they will be.
When grown as an annual, harvest time will be in the late fall. When grown as a perennial, late spring will be the main harvest.
Storage: Store in the refrigerator for up to 2–3 weeks. Artichokes store best in high humidity. If you rub the cut end with a lemon, it will prevent discoloration of the stem.
Fun Fact: According to Greek mythology, the first artichoke was actually a beautiful woman named Cynara. Seduced by Zeus and changed into a goddess, Cynara wasn’t that stoked to obey Zeus’ demand to stay on Mount Olympus forever. Missing her family, she snuck off to see them, and an enraged Zeus decided to punish her by turning her into an artichoke.
Preserve: Artichokes can be pickled for long-term preservation. Use a pressure canner if canning fresh. Can also be preserved in oil.
Artichokes can be frozen but only after they have been cooked by boiling or steaming. You can add lemon juice to the water while cooking to prevent discoloration.
Prepare: Common uses for artichokes are in salads, steamed, in a dip, on pizza, or cooked into casseroles. To prepare, outer leaves are removed until you reach the tender light yellow-green inner leaves. You can cut off the tips of the spiky leaves. The fuzzy central flower bud, called the choke, is removed and discarded before cooking. Trim the stem to the base of the remaining leaves, then steam or boil the artichoke. If you want to cook a whole artichoke, it can be wrapped in foil and baked. You can add chopped garlic in between the leaves of the bud. To eat, simply remove each leaf, and eat the fleshy part of the leaf where it was attached to the stalk. When you reach the center of the artichoke, scrape the choke off the the base and enjoy the heart of the artichoke.
Nutritional: Artichokes contain 47 calories per 100g of flower bud.
Artichokes are high in dietary fiber and antioxidants. The bitter compounds found in artichokes help to reduce cholesterol levels in the blood. Fresh artichokes are a good source of folic acid, vitamin(s) C, K, B, antioxidants, and flavonoids. They also provide necessary dietary minerals including copper, calcium, potassium, iron, manganese, and phosphorus.
Medicinal: Artichokes have traditionally been used in the treatment of constipation, indigestion, high triglycerides, liver disorders, gallstones, dyspepsia, and high cholesterol. It is used as a part of detoxification programs for treating chronic conditions related to liver and kidney function, liver disease, arthritis, and gout. A tea is brewed from the leaves. Artichokes contain cynarin, the active ingredient known to protect the liver, lower cholesterol and triglyceride levels, and treat indigestion.
Warnings: Individuals with allergies to Compositae/Asteraceae (daisy) family plants will want to avoid consuming artichokes without first consulting with a healthcare provider, as they may be allergic.
Try your hand at making these zesty and sweet Stuffed Artichokes.