This tall native wildflower makes a great back border or a annual hedge screen. It needs very little water and will grow on relatively poor soil with little or no maintenance. It flowers fairly late in the season when most other plants are coming to an end so it provides color and flowers when little else is blooming. Deer don't seem to eat it. It is hardy to zone 4.
Perennial sunflowers die back in winter. In spring it produces a rosette of long narrow lance shaped leaves up to 10 inches long. By late spring it begins to send up long slender stems that can grow up to ten feet in height. Each stem is covered in long slender leaves that are alternate up the stem. In early to mid fall it produces numerous yellow flower heads at the end of the stalk. Flowers will appear anywhere from August through November depending on your zone. Here in zone 6 our plants will flower until late October possibly early November depending on the weather. These daisy like flowers can be up to five inches across with bright yellow petals that are deeply veined.
Flowers are very popular with wildlife, butterflies love the flowers and birds adore the seeds.
Will grow on most soil types but seems to prefer a sandy well drained soil. It needs full sun to thrive. It does not use a lot of water so once established does not need watering or any other care. They don't need fertilizing either, this will often produce lush growth and weaker stems which then flop over. For the same reason we strongly suggest that you don't plant it in a very sheltered location. Exposure to the wind helps develop strong stems, and since they grow very tall in sheltered locations they tend to be weaker and flop over. The plants still look attractive but it will encourage them to increase their colony size by dropping seeds further from the plant. In a more exposed location the stems are stronger and make an excellent temporary hedge for screening or some wind shelter.
Cutting it back in the fall is about all you need to do. This is strongly suggested otherwise seed may fall in areas where you don't want the plant to spread to. Once established this plant will form colonies that will spread from the rhizomes or seeds that fall. Be sure that you have sufficient room for this plant and can allow for it to spread before you plant it. To keep the plant under control dig up rhizomes on the edges of the colony. The good thing about this is since they are edible you don't have to waste them! They are very similar to Jerusalem artichoke and were used extensively by native Americans.
Seeds need to be refrigerated over the winter before they will germinate well. All our seeds are refrigerated. Germination is quick and easy. If sowing directly in the ground seed sparsely as the plants will grow quite large. If planting directly try to remove as many weeds as possible for until well established perennial sunflowers are not good at beating out the weeds.
Dividing the plant and growing from rhizomes is a good method of propagation. However plants need to be replanted very soon after digging and well watered in since they don't like being moved. Water frequently after transplanting until plant recovers.
If you want to collect your own seed you many need to bag the heads to ensure you get there before the finches as they love these seeds.
From our experience the deer don't eat this plant. They seem to go around it and eat others instead. Our farm has a pretty high deer population (we back on to a wildlife management area - read hunting land) but we also have other fields around so the deer might just be more choosy about what they eat. I would prefer to list this as not deer preferred rather than deer proof.
The thick tubers can be washed and prepared in the same way as Jerusalem artichoke. They have a similar taste but are not as high yielding. However they do have much showier flowers so being able to eat the roots should be considered a bonus not the main reason to grow them.