Artichoke: Indoor Sow Vegetable or Potted Plant
How to Sow and Plant
Sowing Seed Indoors:
- Wrap artichoke seeds in a damp towel and store in the refrigerator for two weeks before sowing. This will provide the cold period that they need in order to germinate.
- Once chilled, plant seeds ¼ inch deep in individual pots 6-8 weeks before last expected frost.
- Seedlings emerge in 14-21 days.
- As soon as seedlings emerge, provide plenty of light on a sunny windowsill or grow seedlings 3-4 inches beneath fluorescent plant lights turned on 16 hours per day, off for 8 hours at night. Raise the lights as the plants grow taller. Incandescent bulbs will not work for this process because they will get too hot. Most plants require a dark period to grow, do not leave lights on for 24 hours.
- Seedlings do not need much fertilizer, feed when they are 3-4 weeks old using a starter solution (half strength of a complete indoor houseplant food) according to manufacturer’s directions.
- If you are growing in small cells, you may need to transplant the seedlings to 3 or 4 inch pots when seedlings have at least 3 pairs of leaves before transplanting to the garden so they have enough room to develop strong roots
- Before planting in the garden, seedling plants need to be “hardened off”. Accustom young plants to outdoor conditions by moving them to a sheltered place outside for a week. Be sure to protect them from wind and hot sun at first. If frost threatens at night, cover or bring containers indoors, then take them out again in the morning. This hardening off process toughens the plant’s cell structure and reduces transplant shock and scalding.
Planting in the Garden:
- Select a location in full sun with deep, fertile, well-drained soil. In hot areas, afternoon shade is helpful.
- Prepare the bed by turning the soil under to a depth of 8 inches. Level with a rake to remove clumps of grass and stones.
- Set plants 3-4 feet apart in rows 4-5 feet apart.
- Dig a hole for each plant large enough to amply accommodate the root ball.
- Carefully remove the plant from its pot and gently loosen the root ball with your hands to encourage good root development.
- Fill the planting hole with soil to the top and press soil down firmly with your hand leaving a slight depression around the plant to hold water.
- Use the plant tag as a location marker. This is particularly important if you are trying different varieties. It is very difficult to tell which variety is which from the foliage.
- Water thoroughly, so that a puddle forms in the saucer you have created. This settles the plants in, drives out air pockets and results in good root-to-soil contact.
- Mulch deeply to keep the soil as cool as possible.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating. Avoid disturbing the soil around the plants when weeding.
- Keep plants well watered during dry periods to promote rapid, uninterrupted growth. Plants need about 1 inch of rain per week during the growing season. Use a rain gauge to check to see if you need to add water. It’s best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
Harvest and Preserving Tips
- In areas with short growing seasons artichokes will not flower until the second year.
- The flower buds and stalks contain the tender heartmeat that is consumed.
- For single harvest, cut the flower buds and stem by the base of the leaves just before the bud opens, which is about 180 days from transplanting.
- For multiple harvests, cut the flower bud one inch below the bud and allow the stem to send out additional flower buds.
- Successive buds will be smaller than the first, but just as tasty.
- The artichoke petals, heart, and stem all contain the tender fiber that is so delicious when steamed.
- Store fresh artichokes in a sealed plastic bag in the refrigerator for a week.
- Artichoke hearts may be preserved in olive oil, or pickled.
- Artichoke hearts or the whole bed may be blanched and frozen.
Common Disease Problems
Artichoke Curly Dwarf: This virus causes plants to exhibit significant reductions in growth and vigor, and makes them severely stunted. Buds are deformed. Burpee Recommends: Remove affected plants. Contact your Cooperative Extension Service for recommendations.
Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Damping Off: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason. Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer. Burpee Recommends: Keep seedlings moist but do not overwater; avoid over-fertilizing your seedlings; thin out seedlings to avoid overcrowding; make sure the plants are getting good air circulation; if you plant in containers, thoroughly wash them in soapy water and rinse in a ten per cent bleach solution after use.
Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.
Verticillium Wilt: This fungus causes a wilting of the leaves and stems on several branches. Leaf margins cup upward, leaves turn yellow and drop off. If fruit if buds are produced, they are usually smaller than normal. Like fusarium wilt, this will enter through the roots, migrating up the stem and plugging a plant's transport vessels. It is transmitted in the soil. It can also be spread by water and tools. Burpee Recommends: Practice at least a 4 year crop rotation. Remove and burn crop debris.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps which feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Armyworm: Holes in leaves can be singular or clumped together. Leaves can become skeletonized. Egg clusters may be evident on foliage with a cottony or fuzzy appearance. Young larvae are pale green and adults are darker with a light line along the side and pink underside. Burpee Recommends: Introduce natural enemies to the area.
Flea Beetles: These small hopping beetles feed on plant foliage and may spread diseases. Burpee Recommends: Rotate crops with plants in a different plant family. Use floating row covers to prevent damage to young foliage.
Leafminers: These insects bore just under the leaf surface causing irregular serpentine lines. The larvae are yellow cylindrical maggots and the adults are small black and yellow flies. They do not usually kill plants, but disfigure the foliage. Burpee Recommends: Remove affected foliage.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Artichoke FAQs
I received my plant. It is damaged: the bottom leaves are broken/limp, what can I do? This is entirely normal. Artichoke plants shed their outer leaves as new growth emerges from the center.
I grew my artichoke and it didn’t flower. Most varieties (not all) will not produce a crop of flower buds their first year in your garden. Expect buds the second year and for up to three years if artichokes are perennial in your area.
I grew my artichoke-it flowered but didn’t fruit. The edible part of the artichoke is the flower bud before it opens into the flower. Once the flower opens, it is not edible anymore (although it is attractive in the garden!)
How do I over winter my artichoke? Protect the growing center of the plant with loose straw, light mulch or leaf mold. Artichokes will rot if the soil they are in does not drain well.
Can I grow artichokes in containers? Artichokes grow into large plants and do not tend to grow well in a container. If containers are your only choice, use a large one at least 30 inches in diameter and give it extra protection in the winter.