Artichokes (Cynara scolymus) are part of the Asteraceae family, which includes thistles, dandelions and sunflowers. Artichokes have large silvery-green leaves with thick stems that produce flower buds that look like pinecones. Leaves look soft, but they can be quite prickly.
This edible plant is mostly known for its flower buds. However, other parts can be used as well, including its leaf extract which is used for sweeteners, fabric dyes, skin creams, pharmaceutical purposes and beverages (including alcoholic). Artichoke has medicinal benefits and it is also considered a herb.
Where can you Grow Artichokes?
They are native to the Mediterranean region, but they will grow in many places, as long as climate conditions are met. Choose a variety that goes according to your specific area. Plants will not survive temperatures below 25 F (-3 C). Cover your plants with a bucket or frost blanket if there is a threat of frost. Those who live in colder areas should cut artichoke plants back to 8 to 10 inches in late October. Make sure to cover the stump with dead leaves or straw to protect the plant.
Artichokes prefer cool locations with moist summers that range between 70 to 80 F (21 to 26 C) and mild winters between 50 to 60 F (10 to 15 C) to be able to grow as perennials. People who live in USDA zones 7 through 11 can grow artichokes as perennials. Plants should be replaced every four to five years. Those that live in cooler climates should grow them as annuals in the spring. Plant artichoke in the fall if you live in a humid, subtropical area (zones 10 and 11).
Varieties of Artichokes
- Green Globe Artichoke: is considered the original artichoke plant. It can grow in cool climates, even as cold as USDA zone 3. It can tolerate winter temperatures as low as 14 F (-10 C) if well mulched and it can also tolerate warm summers as a perennial.
- Big Heart Artichoke: a thornless variety that can handle warm weather. Grow it as an annual from seed.
- Imperial Star Artichoke: mostly grown as an annual. It is a very adaptable plant that can handle cooler temperatures, up to USDA zones 6 and lower. Easy to grow from seed.
- Violetta Artichoke: also known as Violetto, is an Italian heirloom variety. As its name suggests, its buds have a beautiful purple shade. It is a smaller variety of artichoke, which is great for people with limited space.
How to Reproduce Artichokes
Planting artichokes seeds is risky since they can differ from the parent plant. Those who start these plants from seeds need to be patient since they will take quite some time to grow into mature plants. Start your seeds indoors about two months before the last frost date. Harden off the seedlings before planting them outside. This plant needs to experience a chill to be able to produce buds.
Buying established root crowns is your best option. Nurseries also sell them as container plants during their second year of growth. Plants produce side shoots which should be removed when they are less than 10 inches tall to plant elsewhere or share with friends.
How to Grow Artichokes
Most species grow quite tall so it is important to have enough space in your garden. Normal sizes range between 3 to 6 feet tall and 4 to 5 feet wide. Since they are native to the Mediterranean, they will need full sunlight. This plant can handle some shade, but it is best to place them in a sunny area.
Plant them next to plants which don’t need too much nitrogen, including tarragon, peas and cabbage, as these plants are heavy eaters. Fertilize your plants with an organic vegetable based plant food or fish emulsion every two weeks during the growing season.
Artichokes prefer soil that is rich in nutrients and has a lot of organic matter. A slightly alkaline soil pH that ranges between 6.5 and 7.5 is ideal. Soil needs to have good drainage, otherwise the roots will rot, especially in colder climates.
Those who grow artichokes as perennials need to fix the area before planting to ensure they will continue growing in following years. Consider using raised beds if your soil is poor and not well drained. Make sure to plant them in rows that have at least 4 to 6 feet of separation. Larger plant will shade the smaller plants if you plant them too close.
Apply mulch on the soil to keep it cool around the plant, as excessive heat and hot soil will cause the plant to flower too fast. Composting will allow the plant to retain water in the summer and drain in the winter.
Artichokes need a lot of water, so you will need to water them constantly. Regular watering will keep the flower buds tender and fleshy, as well as encourage strong roots.
It is possible to grow artichoke in large containers that are 24 inches in diameter. Half whisky barrels work as well.
Pest and Diseases
This variety of thistle does not suffer from many pest problems. Slugs can attack young plants, especially if the weather is damp. If you see that your plant’s leaves are turning yellow, then it is best to reduce watering and transplant somewhere with more sun. Check leaves for grey mold (Botrytis) which is a common disease found in artichoke plants. Remove leaves as soon as you see them turn brown or grey since this fungus will spread. Use neem as a fungicide if necessary.
Aphids are another pest that can cause problems. Simply blast them off with a stream of water before they spread. Use neem oil or insecticidal soap for heavier infestations.
How to Harvest Artichokes
Artichoke buds usually start forming early in the summer. The center bud will mature first. Wait until it reaches a diameter of 3 inches before harvesting. Harvest when the bracts are still tightly folded and the bud is firm when handled. Use a gardening life to cut the stems about 1 to 3 inches from the base of the bud.
The plant will start to produce smaller buds once the central bud is harvested. These should be cut when they reach between 1 to 3 inches in diameter. Smaller buds are known to be more tender and flavorful. Harvest before buds open, otherwise they will turn into beautiful purple flowers in your garden. These flowers attract pollinators and can be used for seeds once the blooms have dried.
Trim the top third of the artichoke bud with a serrated knife and remove the two outer layers of leaves. Cut off the stem or peel it with a knife and trim the sharp ends of the remaining outer leaf. After this you can eat your buds.
Dunk the buds in water with lemon juice to prevent them from oxidizing. You can also place them in boiling water for 10 minutes, then drain them. Cut them in half and place them in the freezer or in the fridge with a few drops of water in an airtight container or bag. They will last about a week in the refrigerator.
Don’t forget to prune your plants after harvesting to prepare them for the winter months. Cut the artichoke stem down to a few inches above the soil and mulch.