Last year we started experimenting with our own artichokes in containers. We planted a variety called Italian Purple Globe. It takes seed grown artichokes one year to become established so this year we are looking forward to our first harvest of purple artichokes. At the farmers markets we will be selling Italian Purple Globe transplants and Improved Green Globe crowns. The crowns should produce artichokes this year.
Soil preparation: Although their ancestors were weeds, artichokes are bred for richer soils, so amend the soil with 2-3″ of good garden compost or composted manure and give these large plants plenty of space if you want a good yield. Work the manure or compost into the top 10″ of soil before planting, along with some dolomite lime, dried, ground eggshells, or ground oyster shells for supplemental calcium. Optimal pH for growing artichokes is 6.5-7.0.
Planting: In mild climates, artichokes are grown as perennials, and they produce buds in the second growing season. Plant the nursery plants outside when all danger of frost has past. In warmer climates, plant divisions or set out 6 week old seedlings when nighttime temperatures stay above 50 degrees consistently. Artichokes do best with filtered afternoon shade in the Inland Empire.
Spacing: Plant three feet apart.
Container Planting: Growing artichokes in containers is easy*provided the container is large enough, 24* x 24* x 24*. Artichokes have large root systems, and need a large soil volume*or a rich potting soil in a smaller volume, and much more frequent watering*to form heavy, solid buds. The artichoke gets all it needs in a box or large container with plenty of good compost in the potting mix.
Watering: Growing artichokes requires regular, steady water, 1-1 ” per week. Lots of water at bud set in spring or summer helps produce large, dense, chokes..
Fertilizing: Artichokes are heavy feeders, even if you build organic soil amendments into the soil at the start of the season. Just before they start to bud out, side-dress with composted chicken manure (1-2 lbs) or a good organic fertilizer like EB Stone Tomato, Vegetable, and Herb Fertilizer, then water thoroughly.
Keep an eye out for aphids, caterpillars, slugs and snails.
You can harvest your artichokes any time after the flower buds form until they start to open. Artichoke flavor is not dependent on maturity the way it is with a tomato. Slice the buds off at the base using a sharp knife.
Plant Care: You can keep your artichokes from one season to the next. In USDA Plant Hardiness Zones 7 and warmer, protect the plants with a thick mulch of straw or cover with heavy burlap. If you’re growing artichokes as perennials, you have to cut the plants back after they flower, and mulch them to keep them from freezing in colder zones. You might get another couple years of productivity out of the plants if you divide them after the first 3 years, and plant the divisions as separate plants.
Notes for Growing in Zone 9: Here in the hot Inland Empire it is best to plant artichokes in the fall and let them overwinter through our rainy season unprotected. You can broadcast seeds or plant seedlings, both work. The plants grow through the winter, put on a big burst of growth in March and April, then flower in May. We eat the big, dense artichokes from the middle of the plant first, then harvest the abundant baby chokes that follow until mid-June. In July, with the peak of summer heat coming, we cut them back. They re-sprout in August, leaf out in the fall, and grow through winter, then flower again the next spring.