Rich in antioxidants.a type of perennial sunflower, helianthus tuberosus is grown for its attractive flowers and for its edible tubers. In late summer to early autumn it will produce masses of showy, bright yellow flowers on tall stems which are attractive to both birds and butterflies. They are also ideal for as dried flowers.well suited to the british climate, the tasty tubers are highly nutritious and can be eaten raw or cooked, boiled, grilled or roasted like potatoes. Harvest your artichokes in the autumn, once the leaves have died back down or if you can wait, after the first frosts. Be sure to leave some in the ground for the following year.