Helianthus annuus: The Long Journey of the Immutable Sunflower

Background and History

What says summer like sunflowers? These beautiful pollinator attractors have a long and rich history. We wanted to spotlight these gems that are known to elicit smiles on the faces of all who behold them.

Sunflowers are members of the family Asteraceae. This family includes daisies, dandelions, and lettuce! Sunflowers typically have 1,000 to 1,400 florets (and potentially the same number of seeds per head). 

Sunflowers may have been domesticated before corn as early as 3000 BC in present day Mexico. Various tribes collected their seeds and ground them into flour to make bread. North American Indigenous people also extracted dye and oil from sunflowers for a variety of uses. The Incas saw the sunflower as a symbol of the Sun God.

Europeans brought back sunflowers from North America in the late 16^th century, and cultivated the original tall flower with small seeds into countless varieties with larger seeds ideal for extracting oil. Peter the Great liked sunflowers (he was 6’8”, perhaps he saw them at eye level?) so much, that he encouraged private citizens and companies to grow them throughout Russia.

By 1970, over 5 million acres of sunflowers were being grown in the US alone! Varieties vary in color, size, branching abilities, and whether they produce pollen and seeds.

Selecting the Right Sunflowers for You

Sunflowers make great container plants and definitely bring all the pollinators to the yard! The best sunflowers for your container garden is dependent upon the size of your containers and your own preferences (color, bloom size, desired spread, whether you want cutting flowers or plan to indulge in snacking).

Colors and Hues

Other than the common yellow, there are bicolor (usually blends of yellow and orange), and varieties that produce red, white, and purple blooms.

Size

Shorter or dwarf varieties are typically best for container gardens, with five-gallon planters being suitable for 2-4 ft high varieties and 7-10 gallon planters more suitable for those ~4-6 ft tall.  See our Planting Guide for container recommendations. The taller the sunflower and the larger the flower head, the increased likelihood that they will require staking.

Here are some sunflower options from popular online seed/nursery retailers:

You can also decide whether you would prefer single-stem flowers or branching stems with multiple blooms.

General Sunflower Types

Cutting sunflowers are often hybrids, cultivated to be pollenless, making them less messy when placed in bouquets, and when placed in vases upon tabletops.  While this design makes them convenient, it means less sustenance for pollinators who rely upon both pollen and nectar.  Cutting hybrids only have nectar to offer.

Pollinator-friendly sunflowers, are often the type that branch, growing multiple flowerheads, provide pollen and nectar for a variety of bees, hummingbirds, and butterflies, and once pollinated and mature, seeds for wildlife like birds, squirrels, chipmunks.

Snacking sunflowers are cultivated to form larger, tasty seeds, preferrable for human consumption.  If snacking is what you want, timing is everything! 

When to Sow

Sunflowers grow best when directly sown in warm soil outdoors after threats of frost are long gone.  They germinate best in soil temperatures of 70-80 degrees.  Once the outdoor temperatures are consistently near 70 degrees, it is a good time to sow.  *Note:  Placing black plastic mulching covers/sheets over the soil for several days before sowing can increase soil temperatures.

Dead-Heading

Promote continuous blooms with branching sunflower varieties by cutting the flower heads off at the junction just above the leaf pair below it.  Eventually new blooms will grow, as the plant can divert its energy toward new growth.

Cutting Sunflowers

Cut sunflowers early in the morning, and select blooms that have opening outer petals, but inner petals that have not yet opened.  Ensure that you have sanitized your pruning shears first.  I usually use rubbing alcohol wipes to clean my shears before and in between cuttings.  Cut the stem at a 45 degree angle, common practice when cutting flowers for vases/bouquets.  Remove all leaves other than the uppermost and then promptly place cut sunflowers in a vase.

Harvesting Your Seeds

You may want to harvest your seeds so that you can roast them for snacking or maybe save them for the next planting season.

You will surely have competition in getting to the seeds first! Once the seeds are developed, the petals usually dry out and fall off and the flower head begins to droop.  If you haven’t already, this is a good time to cover the flower heads with a protective barrier (i.e., tightly woven, breathable mesh sacks made for fruits/vegetables, cheesecloth, paper bag). 

When the backs of the flower heads have changed to yellow, you can begin the harvesting process.  In this instance, you cut off the stem with the flower head and can hang it in a cool dry location to complete drying out. 

Another option is to wait until the backs of the flower heads are black, this usually occurs when you have allowed the seeds to dry out before cutting off the flower head.  However, the latter method prolongs the temptation for your natural competitors, and may require a more vigilant gardener. Let the games begin! 

Are you convinced, yet?

Four Reasons to Grow Sunflowers in Your Container Garden

1. Sunflowers make beautiful cut flowers!
2. The flower heads of some sunflower varieties can be saved, dried and the seeds removed for snacking!
3. Attract birds to your garden – Birds will eat your sunflower seeds, but they will also eat insects!
4. Attract and feed your pollinators!  Honey bees and native bees like the bumble bee love the nectar and pollen from sunflowers.

More Sunflower Showstoppers: