Artichoke

Start seeds indoors 8 to 12 weeks before transplanting out. Artichoke seeds germinate best after a period of cold stratification in the fridge. Artichoke plants also require a ~10-day period of cool (but not freezing) temperatures below 50°F (10°C) to induce flowering. After hardening seedlings place them in a cold frame or use other means of protection to expose them to cool spring temperatures without allowing them to freeze. In climates with milder winters artichokes can be sown in the fall for a spring harvest.

Artichokes can grow very large, sometimes 4 feet in diameter so spacing is very important. When grown as an annual, they must be planted in spring. In warmer zones where they survive as perennials, plant as seeds in late summer or transplant in mid-autumn. Artichokes produce for about three to five years and will develop side shoots at their bases. At this time, you can lift, divide, and replant the new shoots. To grow artichokes as perennials, over-winter them according to your planting zone. For zones 8 and warmer, after the last harvest, cut the plants to soil level and cover with 2 to 4 inches of mulch (staw works well). For zones 6 to 7, after the last harvest , cut the plants down to about 12 to 18 inches. Cover the plant with organic mulch, like straw, leaves, or even compost, and then cover that with a large basket. Mound another layer of straw or leaves over the basket and cover everything with a waterproof tarp. Zone 5 and cooler: You can try the method described for zones 6 to 7, or you can pot up your plants, move them to a dark spot that stays cool, but above freezing, and water them occasionally throughout the winter. In the spring, move the pots back outdoors after all danger of frost, and either replant the artichokes in soil or continue to grow them in the containers.