With their large leaves and sturdy rosettes, the artichoke is a distinctive plant. A herbaceous perennial, artichokes are part of the asteraceae family alongside sunflowers, thistles and dandelions.
These unusual, architectural vegetables are commonly grown for their edible flower buds that are harvested before the flowers open. But they also have ornamental value. Despite looking soft, the arching, silver green leaves can feel prickly. Beyond the foliage you can find thick, fleshy stems. As the flower forms a tender, flavorful bud, known as the artichoke heart also develops. This can be harvested for culinary purposes or left in place. If left in place the plant flowers produce large, purple thistle like flowers with a pleasant aroma.
Popular in the Mediterranean, from where they originate, these tall branching specimens are not as common in the United States outside California. However, while they may not be common, the artichoke plant (Cynara scolymus) is surprisingly easy to grow. If this attractive specimen interests you, why not add some to your garden? Despite their unusual appearance they are pleasingly easy to grow. If you want to learn how, this is your complete guide to growing artichokes.
Growing artichokes adds interest and drama to the garden. Attractive ornamental plants, they also have many culinary qualities.
Selecting an Artichoke Variety
Also known as green, globe or French artichokes, most varieties are hardy in USDA zones 7 to 11. These resilient plants prefer cooler climates where they happily grow as annuals. In warmer climates you can also grow the plants as short lived perennial vegetables.
When selecting a variety try to choose a modern or heirloom artichoke. Avoid Chinese and Jerusalem artichokes, these are not true artichoke plants. The Chinese artichoke is actually the rhizome of the plant while the Jerusalem artichoke is a member of the sunflower family that is grown for its edible tubers.
One of the best artichoke cultivars is the Globe cultivar which produces the classic, large round artichoke heads. Green Globe is commonly grown in California but tends to struggle in conditions that are not ideal.
Green Globe cultivars like fertile, well draining sunny sites. Once established they are pleasingly drought tolerant.
Other popular cultivars include:
- Gros vert de Laon, a French heirloom cultivar which is grown for its large, attractive hearts.
- Colorado Star, a small cultivar which is rich in flavor. It is also one of the earliest cultivars to mature.
- Emerald is a reliable cultivar which produces large, round green heads without spines.
- Violetto is an Italian heirloom cultivar. It is prized for its production of numerous small side shoots.
- Imperial Star is a versatile plant which is easy to grow from seed. It can be grown as an annual. Ideal for zones 6 and colder.
- Purple of Romagna is a tender italian heirloom with good tasting flower buds. An attractive plant, it is a popular choice for ornamental gardens,
- Big Heart is a thornless variety that is partly heat tolerant.
There are a range of different cultivars which are all pleasingly easy to grow.
Growing artichokes from seed is a lengthy process. Most varieties need between 85 and 100 days to mature. In warmer climates if you are growing artichokes from seed, you will need to start sowing the seeds in late summer so that they are ready for transplanting in mid fall. Additionally, it can take up to 2 years for growing artichokes to mature and flower.
To speed up the process, artichoke plants are commonly sold as either container plants already in their second year of growth or as established root crowns. When selecting your plant or root crown, try to select the healthiest possible specimen. This makes transplanting and growing artichokes a lot easier.
Where to Plant
Growing artichokes thrive in fertile, well draining, pH neutral soil. A sandy, Mediterranean type soil is ideal.
Your chosen location should be as light and sunny as possible. Planting in too shady a position can deter flowering.
When selecting your planting site, bear in mind the final size of the plant. Mature artichoke plants can be between 3 and 6 ft tall and around 5 ft wide.
If your soil is poor, take the time to amend it before planting. You can also grow the plants in raised beds or planters.
Unlike many vegetables, growing artichokes don’t fit into a crop rotation system. This means that you can plant them wherever you have room.
The artichoke does best in well draining, sunny positions.
How to Plant
When you start growing artichokes depends on your climate. Growing artichokes as annual plants is recommended for growers in cooler climates that don’t want to protect the plants overwinter. If this is the case, plant in the spring. In warmer areas, where the plants grow as perennials, you can plant in the fall.
Prepare your chosen planting site by diggin over the area, working in lots of organic matter as you do so.
Dig a hole large enough to comfortably hold the rootball. Place the plant in the hole, the crown of leaves should sit at soil level. You may need to add or remove some soil before you get the positioning exactly right. When you are happy with the position of the plant, backfill the hole with a mix of organic matter and excavated soil.
Gently firm down the soil and spread a granular, general purpose fertilizer around the plant. Water well before applying a 2 to 3 inch layer of organic mulch.
If you are planting in pots, fill a large pot, at least 3 ft wide and 1 ft deep, with good quality, well draining potting soil. Plant as described above and water well.
Growing artichokes require lots of room to develop.
Caring for Growing Artichokes
After planting, mulch the soil around the plants. This is particularly useful if you are growing artichokes in a warm area. Ideally temperatures should be between 70 and 80 ℉ in the summer and 50 to 60 ℉ during the winter months. In warmer areas mulching helps to keep the soil and the roots cool. This prevents flowers from emerging too early in the growing process.
Use a hose to water growing artichokes regularly and deeply. Depending on the amount of rainfall this can be anything from one to three times a week. Regularly watering helps to keep the buds tender and fleshy. It also encourages a strong root system to form. A strong root system is vital for encouraging plants to stand upright and not topple over onto the floor.
Remember plants growing in pots and planters may require more regular watering than those growing in the ground.
Mulch the soil in the spring with rich home made compost or well rotted manure. Apply a balanced vegetable plant food every two weeks during the growing season.
A regular dose of fertilizer encourages buds to form.
Pruning Artichoke Plants
These low maintenance plants require little regular pruning. In the fall use a small garden scissors to cut back old foliage and, if necessary, mulch to protect the plants from winter temperatures.
After 3 to 5 years of continuous, healthy growth artichokes develop side shoots. These emerge from the base of the plant. Prune away and discard the shoots. Or, if you want to propagate new artichoke plants, lift the plant and divide the shoots.
Lift and divide the plants every 4 years to keep them vigorous and productive. This is also the easiest way to propagate artichoke plants. I will explain how to divide and propagate growing artichokes later in the article.
Growing artichokes as perennials, or in cooler climates means that you must protect them against winter temperatures and frosts. How much action you must take depends on what USDA zone you are growing artichokes in.
In zones 8 and higher cut the plants down to soil level when the last flowers start to fade. Cover the soil above the root system with a 2 to 4 inch layer of organic mulch.
If you are growing in zones 6 and 7, cut down the plants after the last harvest to about 12 to 18 inches above soil level. Cover the plants with an organic mulch such as leaves, straw or compost. Cover the mulch with a large basket or cloch before mounding more straw and leaves on top. I find these GrowAway Reusable Garden Cloche Domes a great way to protect sensitive plants from the weather. Cover the mound with waterproof tarp.
Finally, growers in zones 5 and colder can either cut back and cover the plants as described for growers in zones 6 and 7 or transplant the dormant artichoke plants into pots filled with fresh potting soil.
Place the pots in a sheltered, cool, dark position such as an unheated garage. Water the plants occasionally throughout winter to prevent the soil from completely drying out. In spring return pots outside after the last frost has passed and either replant or continue to grow your artichokes in pots.
Whatever zone you are growing artichokes in, remove the coverings the following spring as soon as the soil thaws and no hard frosts are expected.
When planting, there are no plants that you should avoid positioning neary your artichoke. But be mindful of the size of an artichoke plant. As they grow these develop into large plants that can easily smother nearby smaller specimens.
Peas make for good companion plants because they add nitrogen to the soil. Growing artichokes thrive on nitrogen. Other good companions include:
How to Propagate an Artichoke
You can propagate artichoke plants either by harvesting and sowing seeds or dividing a mature plant.
Propagation by Division
The easiest way to propagate new plants is by dividing mature plants. This is a far quicker and more reliable way to get new artichoke plants than harvesting and sowing seeds. Division also helps to rejuvenate the original, mature plant.
As growing artichokes mature they send out offshoots. Allow the offshoots to reach about 8 inches in length before dividing. Use a spade or shovel to dig a circle around the offshoot. Loosen as much of the soil as possible. When you can clearly see the point where the offshoot joins the parent plant, use a spade or sharp knife to cut away the offshoot and some of its roots.
After removing the offshoot, repack the soil around the plant. Plant your offshoot in a prepared position in moist, well draining soil.
Harvesting and Sowing Seeds
As flowers fade seeds form at the center of the flower, much like a dandelion head.
Allow the seeds to mature before harvesting. Keep the largest seeds, these should feel hard when squeezed between the fingers. Allow the seeds to dry out in a cool, dry location before storing in a labeled paper envelope or air tight container, such as a Kitchen Storage Mason Jar.
Be warned, if you are saving seeds from plants growing in the garden they may not grow true to type. If you want an exact replica purchase seed produced under controlled conditions.
The fluffy seed heads are similar to dandelions.
Start the seeds undercover at least 8 weeks before the last predicted frost date. Fill trays or pots with moist potting soil. Scatter the seeds along the top of the potting medium before covering with a thin layer of soil. Don’t plant the seeds too deeply, this can hamper germination. Place the trays in a warm, light position. Ideally the temperature should average between 65 and 70 ℉. You may need to place the pots under grow lights to encourage germination.
Following germination, continue to grow seedlings in a warm, light position. Regularly moisten the soil, being careful not to disturb the seedlings. When the seedlings are large enough to handle, transplant them into individual 4 inch pots.
Don’t wait until the last frost date has passed before hardening off the seedlings. The plants need to experience a slight chill before flower buds can set. Allow the seedlings to sit out in temperatures of 45 to 50 ℉ for 7 to 10 days.
You can also sow the seeds directly into their final position in either March or April, depending on where you are growing artichokes. Directly sow 2 to 3 seeds in a shallow hole. Space the seed groups roughly 12 inches apart. Following germination, when they are large enough to handle, thin out the seedlings. If all 3 seedlings have germinated, pick out the weakest two, allowing only the strongest to remain. The seedlings can be thinned out for a second time a few weeks later to a spacing of 2 ft.
Common Artichoke Problems
Growing artichokes is a pleasantly low maintenance practice. If planted in a favorable position and correctly cared for disease and illness is rarely a problem.
Botrytis, or grey mould, can affect leaves and flower bracts. A nasty fungus which targets damaged or stressed plants, botrytis can cause leaves to turn brown and then gray. Lift and destroy affected leaves. If grey mould is a persistent issue fungicides or neem oil can be used to treat infestations.
A number of pests, such as young earwigs, can also target growing artichokes. While the pests create holes in the shoots the damage is largely cosmetic and unlikely to seriously harm a healthy plant.
Slugs can be problematic in damp weather when leaves are young and tender.
Popular with beneficial insects and pollinators, regularly check the foliage for signs of infestation.
Aphids also like to target the foliage of the plants. Regularly check the plants for signs of infestation. Wash pests away with a blast from a hose. Persistent infestations can be treated with an application of homemade insecticidal soap.
Finally, the small larvae of the artichoke plume moth can target the buds. Should you notice any signs of infestation use an insecticide to treat the issue.
How to Harvest your Artichokes
If you are growing artichokes as perennials, in the first year, allow the plants to grow without removing the flowerheads. In the second year, allow heads to develop before harvesting.
In ideal conditions plants produce buds periodically throughout the year. But in most areas buds form in early summer.
Harvest buds as soon as they are large and firm.
The central bud, also known as the terminal bud, matures first. Harvest this as soon as it reaches 3 inches in diameter. Harvest the bud while the bracts are still tightly folded together and it feels firm. Use a scissors to cut 1 to 3 inches of the stem along with the bud. This makes it easier to handle.
After harvesting the central bud, the side shoots begin to produce smaller buds. Again, these can be harvested when firm again 1 to 3 inch diameter. Small buds can be tender and flavorful.
Raw artichokes rarely store well and should be used as soon after harvest as possible. Cooked vegetables can be stored in a refrigerator for several days.
Distinctive plants, growing artichokes is a great way to add drama and structure to a garden.
These tall, arching thistle like plants are pleasingly easy to grow and add interest to flower beds, borders and vegetable gardens. If you don’t want to eat the vegetables it is worth growing artichokes purely for their ornamental interest. Why not add a couple of artichoke plants to your garden this summer?