When we think of polytunnel growing we tend to focus on annual crops such as tomatoes and peppers. But a polytunnel can also offer a protected space to grow perennial vegetables that will grow in the same spot year after year. The artichoke is one of the best known perennial vegetables. It could be a good choice for those who want options for their polytunnel that will not involve quite as much work. Perennial polytunnel crops can grow happily undercover year after year and as long as their water and nutrition needs are taken care of, they will not require as much work as some other polytunnel crops. Perennial vegetables can be a sustainable choice, in the polytunnel or elsewhere in the garden.
Artichokes are not likely to be the best choice for small polytunnels, since they require quite a lot of space to grow well. Plants will each need around 1m² of space. However, for a larger polytunnel, they could offer a good option for a permaculture polytunnel, in a mixed, poly-culture permanent bed. Good companions for artichokes could include legumes for nitrogen fixing, sunflowers, tarragon and perhaps some perennial brassicas.
A large polytunnel could give northern growers the option to grow artichoke varieties that are not frost hardy in the UK.
Artichokes are not usually grown from seed but are grown from offsets that are taken from the parent plants in the autumn. They can also be grown from seed and will usually flower in the year of planting, though they can be fussy and are not a vegetable that beginners should attempt to grow from seed.
Whether in the polytunnel or elsewhere in the garden, artichokes will need rich soil – they are very hungry plants. They are not too fussy, however, about the type of soil and will thrive in most conditions except heavy clay. Water consistently and do not allow soil to become waterlogged.
Good drainage, no heavy clay.
Plant 1 metre apart, 1 metre between rows.
Keep plants well-watered until established.
Feed fortnightly through summer.
Cut foliage down in late autumn and cover crowns with straw.
The first-year flower heads will be small and should be cut off and discarded. The second year, heads that are golf ball-sized or larger can be utilised in the kitchen. They should be harvested before they open and begin to flower and should be cut from the plant along with around 10cm of stem. After you have taken the main head, secondary heads will form on mature plants and these can also be eaten. You can plant artichokes in April and can expect to harvest between July and September. After a few years, you should renew your plants as the yield will begin to drop with more aged artichokes.
Planting time – April.
Expected cutting time – July to September.