Artichokes are native to the Mediterranean area of the world and if grown as perennials, they need to be grown in USDA zones 8-11. So, if you are not in these zones, grow Artichokes as annuals. To do this, we need to pull the wool over Mother Nature’s eyes — yes fool Mother Nature…
Artichokes is a biannual which means that its growth cycle is to establish roots and the plant the first year and the second year to produce buds and then flowers then seeds. Well, if you are growing as an annual, this can be a problem unless you engage in a little trickery.
An Artichoke grows 3-5 buds per plant in the spring and then again in the fall, so succession planting isn’t necessary. Soak seeds in warm water for 48 hours. Sow seeds indoors in January at a depth of 1/4″ in 4″ pots and in soil that is between 70-80 degrees F. It will take about 10-14 days to germinate. For the next 6 weeks, keep in an area of the house where the temperatures are between 60-70 degrees F during the day and between 50-60 degrees F at night.
For the next 11 days, you need to trick your Artichoke plants. Place them in an are where they are not exposed to frost, but maintain a cold temperature of between 32-50 degrees F for the next 4 weeks.
After this period, feel free to transplant your Artichokes when soil temperatures are above 60 degrees F and there is no danger of frost. Plant Artichokes 2 feet apart in soil with a pH range of 6.5-8.0. Feed once a month with compost tea or fish fertilizer. Water heavily and evenly at the roots.
Harvest in mid to late spring when weather is cool and moist. Select the top bud first then the other buds, using a sharp knife, cut the base of the bud when the leaves are tight.
Allow 10 buds to flower out and become thistles. Bag the flowers, the pollen will drop into the bag 5 days before the stigmas are receptive. Shake the bags daily to ensure pollination. After the feathery pappus starts to show, bag the head and cut from the stem. Dry the head in a warm spot until it is brittle. Flail the head in the bag, separating the plant material from the seed. Then winnow the seed, removing all plant and flower material.
Dig up roots in cold regions to transplant next spring into a hot bed in mid February. Just before winter, cut back plants to just below soil and cover with mulch in warm regions.