Part of the thistle family, globe artichokes can be grown as an edible garden plant or as a stunning architectural aspect to your landscape. These luscious herbaceous perennials produce flower buds that can be eaten raw, steamed, or pickled like their store-bought equivalent, or the flowers can be left to open, producing stunning purple flowers.
Globe artichokes can be grown as either a perennial or annual plant, depending on the growing zone and the winter temperatures. These half-hardy thistles originated in the southern Mediterranean and will be killed by temperatures before 20 degrees Fahrenheit. If your winters are colder than this, it's best to plant them as annual plants.
- Start seeds indoors
Globe artichokes need a long growing period to come to maturity and develop the buds that are harvested to eat. Plant seeds indoors about 8 weeks before the last frost date. Seeds will germinate in about a week's time.
- Plant outside before last frost
About a month before the last frost in your area, move your seedlings outside and plant them in the garden. According to Dengarden, globe artichokes need temperatures below 45 degrees to trigger flowering.
- Space plants 3 feet apart
Plants can grow upwards of 5' tall, so it's important they are properly spaced. When transplanting seedlings outside give them 3' between plants so there isn't competition for sunlight, water, or soil nutrients.
- Fertilize with high nitrogen
A month after planting (or late spring if growing as perennials), drench plants with a high nitrogen fertilizer to promote vegetative growth.
- Keep weed free
One of the best ways to keep weeds down around the plants is to heavily mulch with well decomposed compost or manure. Spread 3-4" around the base of plants, making sure to avoid touching the stems.
- Harvest main bud first
Plants will send up a stalk in early summer that will develop the flower buds. Harvest the main bud when it reaches about 3" in diameter, before it begins to open up. Removing the main bud will cause secondary buds to appear; they will be smaller in size but can still be harvested to eat.
- Protect from cold winter temperatures
If you are growing your globe artichokes as perennials, make sure to cover them with a solid layer of straw or mulch in the fall if you live in a colder climate. This will help protect them over the winter from the frigid temperatures.
- Divide plants every 2 to 3 years
To keep your stock healthy and vigorous (if growing globe artichokes as perennial plants), it's best to divide plants every couple of years. This keeps them from getting too crowded and fighting for nutrients and water in the soil. My Productive Backyard provides a step by step account on how to divide plants.