Sunflowers are bright cheerful annuals that start blooming in August when other flowers are starting to fade. The size of plant and flower is dependent on the variety and how close together they are planted. Yellow petals with a brown center is the colour of the sunflowers that were grown by Indigenous Americans. While this variety is still the most common they are also available in various shades of red and stripes.
Sunflowers are one of the easiest plants to grow as seen by them popping up in odd places when the seeds are dropped by birds or squirrels.
While sunflowers do best in a sunny location, they will tolerate part shade. Sunflowers grow in most soils as long as there is sufficient moisture. When watering try to apply an inch (2.54 cm) which will encourage the plants to develop a deep root system. If the soil is dry for a long period of time after the sunflower has germinated, the plants will be short and the flower small.
Sunflower plants are divided into two categories: single stems and branching.
Single stemmed plants produce one flower. Some varieties have complete flowers while others are bred for the flower market and do not produce pollen. Seeds will still be produced if there is a sunflower with a complete flower, in the vicinity. Plant single stemmed sunflowers close together and the plants will be short with a flower small. Give the plant at least a foot of growing space and the plant and flowerhead will increase in size.
Single stemmed sunflowers tend to make better cut flowers as the flowers last a long time.
Branching sunflowers produce many smaller flowers over a long period of time. A branching stem is thinner than the single headed sunflower and may break or bend if the flowerheads become too heavy.
Tall sunflower plants develop an extensive root system which keeps them upright. Expect to find lateral roots spreading up to a foot on each side of the stem. It holds that plant, gathers nutrients but can be hard to pull in the fall.
Sunflowers rarely suffer insect damage but they do attract wildlife such as bees, deer, squirrels and birds. Bees feed on the nectar and pollen depending on the variety.
Deer eat the developing flower bud and will knock plants over to reach it.
Squirrels will run up the stems on large stocks to gather seeds. The weight of the squirrels can bend or break the stocks.
Birds feed and spread the seeds in the flowerhead.
For those that do not want to clean up the mess of seeds, there are seedless hybrids available. The seeds of these plants will cost more but they produce less mess, seeds, and attract fewer critters.
Linda Tomlinson has gardened in Central Alberta for over 30 years. She can be reached at firstname.lastname@example.org.