Written by Rhonda Ferree, retired horticulture educator
Sunflowers are popular. It seems one can find a sunflower on almost anything, from throw pillows to towels to floor mats and rugs. I've also noticed more and more gardeners growing sunflowers for their beauty, their tasty seeds, or for wild bird feed. My son Tyler has several sunflowers growing in his vegetable garden this year.
True sunflowers are in the plant genus Helianthus and include about 70 species in the Aster family. All but three are native to North America.
I often see our native sunflowers growing along roadsides in central Illinois. These include the annual sunflower (Helianthus annuus) as well as the fall blooming Jerusalem artichoke (Helianthus tuberosus). Jerusalem artichoke has 2 – 3 inch yellow flowers with yellow centers on 2 to 8 foot tall plants. It is also known as the 'Indian Potato' because the Native Americans cultivated it and ate the edible root tubers.
The sunflower is often grown as a garden plant. It is easy to grow and even tolerates heat and drought. Simply sow the seeds, after danger of frost, in the sunny garden.
In recent years, there has been an explosion of different types of sunflowers available to home gardeners. Some varieties grow extremely tall, while others have been developed for ornamental use with multiple yellow, red, white or a combination of colored flower heads. I like to categorize them as single stem, branching, or dwarf.
'Teddy Bear' is a nice dwarf one (24") with a showy, fuzzy, fluffy flower. This double flower is brilliant golden yellow with no "centers". The dwarf 'Sunspot' looks more like the traditional sunflower, but only grows 2 ½ feet tall.
'Mammoth Russian' and 'Grey Striped' are tall single stem varieties. They grow 6-12 feet tall with a single 12 to 24 inch seed head on each sturdy stalk. 'Giant Sungold' is a full-sized version of the dwarf Teddy Bear. It grows 10-inch, super-double flowers on 6 to 7 foot plants.
Have you ever passed a sunflower field and noticed that all the flower heads face east? Some researchers refer to this as solar tracking. On sunny days, immature flower buds of some sunflowers track the sun across the sky from east to west. However, as the flower bud matures and blossoms, the stem stiffens and the flower becomes fixed facing the eastward direction.
Another interesting fact about sunflowers is that their hulls have a toxin that prevents the growth of other plants. You might have noticed that soil is often bare under birdfeeders where sunflower hulls accumulate on the ground. This is called allopathy. Remove the hulls regularly or site the feeder where there is no danger of damage to lawns or other desirable vegetation.
Add some cheer to your garden with sunflowers.
MEET THE AUTHOR
As horticulture educator, Rhonda Ferree inspired citizens in local communities to grow their own food and improve their home landscapes. She focused on high quality, impactful programs that taught homeowners how to create energy-efficient landscapes using sustainable practices that increase property values and help the environment.
After 30 years with University of Illinois Extension, Rhonda retired in 2018. She continues to share her passion for horticulture related topics as “Retro Rhonda” on social media.
ABOUT THE BLOG
ILRiverHort is a blog that helps people connect to nature and grow.