It’s time to start some seeds!
Although it’s way too early to start tomato, and even broccoli seeds indoors in Chicago, it is the right time to start other edibles like celeriac and globe artichokes.
Globe artichokes (not to be confused with Jerusalem artichokes) are a perennial plant in warmer climates (zones 7-10), but they can be grown as an annual in Chicagoland. They are large plants and take a long time to produce from seed to harvest, so make sure you have the space and time to dedicate for growing as much as you want to eat. As most of the artichokes in our grocery stores come from California (sometimes weeks after harvest) growing your own tender buds can be a real treat!
Artichokes should be started indoors from seed early- through mid-February in Chicagoland. Artichokes generally require warm soil temperatures to germinate, so a seedling heat mat will be helpful if the seed-starting area in your home is cooler than 70F. After germination, they can grow in temperatures as low as 60F, so that’s a good time to remove the seedling heat mat.
The important thing to remember about growing artichokes as annuals is to make sure the seedlings are exposed to at least 10 days of cool (below 50F) temperatures after germination. This chilling period, known as vernalization, will help induce flowering in the plants so you are sure to have buds (which are the edible parts) to harvest. Vernalization is tricky to simulate (perennial-grown artichokes experience this naturally during the few cool nights in their native climates), but it can be done!
Here are some tips:
-When you are ready to start vernalization (usually in mid-April), make sure your seedlings have at least 2 sets of true leaves and go through a full hardening-off. They need to be hardened-off not only to adjust to outside temperature fluctuations, but also stronger wind and much-brighter sunlight.
-Set out your seedlings (keep them in pots) when nights are reliably no lower than 45F. If temperatures dip and there’s a frost warning, you can use a row cover to add a few degrees of warmth and protection (but be sure to remove during the day if temperatures are above 45F so the plants properly experience the chilling period).
-After vernalization, transplant your seedlings into the garden in soil with a high amount of organic matter and the correct amount of all-purpose fertilizer (application rates will be on the fertilizer label). Artichoke plants get very large, so be sure to give each plant spacing of at least 3′.
-Harvest your artichokes after the flower buds have swelled, but while they are still tight and unopened. If left on the plant too long, the gorgeous blossom will bloom