Sunflowers ready to harvest as summer ends

Forget Jack and the Beanstalk. I want to grow giant sunflowers.

Tall stalks of green foliage with droopy yellow, seed-filled flower heads. What fun!

The National Garden Bureau named sunflowers (Helianthus annuus) the 2021 Flower of the Year. No wonder, who doesn’t smile when they see a patch of sunflowers.

The tallest varieties can be 16 feet tall, with flower heads one foot in diameter. Is that too big for your garden? Don’t worry. There are many other varieties, the smallest bred for container gardens reaching about 12 inches tall.
Sunflowers are an easy plant to add to your garden, but pick your spot carefully. Because the plant can grow high, it may cause shade for nearby plants. The best location for sunflowers will receive 6-8 hours of direct sun.
Plant the seeds directly into the soil after the last frost. Take some extra time and prepare the bed. Although the seeds only need to be placed one-and-a-half inches into the soil, it is a good idea to loosen the soil deeper and wider. Sunflowers have long taproots. The root system is essential — it must be healthy and strong to hold the tall stems and help them withstand any summer wind.
Be sure to add organic matter to the soil and maybe even a slow-release fertilizer when planting. Then water like crazy around the root base. Once the plant is established, aim to water weekly and water deeply. This will encourage the roots to grow deep looking for water.

Birds may be attracted to the newly planted seeds. If so, cover them with netting until they have sprouted through the ground. Once the plant is up, be cautious of deer tasting the tender stems.

You may want to have a little fun when planting. Think about the stalks forming a teepee as they grow or use wire arches to train them and create a sunflower tunnel. Both are especially delightful if you have children visiting your garden.

Early fall is the time to harvest the flowers. If you are using them in an arrangement, leave the stem long to create height and drama. If you are harvesting the seeds, cut the stems about six inches long.

You will know it is time to harvest. The plant’s foliage will begin to yellow, the center of the flower head will turn brown, and it will droop. Depending on the end-use, there are different ways to harvest the seeds.

You might want to save a bowl for yourself; salty roasted seeds are delicious.


Pick a place away from wildlife to let the heads dry. Then harvesting should be as easy as rubbing your hand across the seeds and letting them fall into a tray or using a fork to gently rake them loose.

If you want the seeds for next year’s sowing, make sure they are completely dry, then store them in an 
airtight container. If you plan to use them for birdseed, you will not need to be as careful with storage. It’s messy, but you can hang the intact flowers and let the birds pull the seeds.
Fun fact: sunflowers are often thought of as the fourth sister in reference to the Three Sisters of planting, corn, squash, and beans.

If you think all this sunflower talk is for the birds, consider this: in 1987, Vincent Van Gogh’s “Sunflowers” painting sold to an anonymous buyer for $39 million. That is a lot of birdseed!

Make a note in your garden journal, calendar, or phone to plant a few of these golden giants next spring. When the calendar turns to fall, you will be rewarded with flowers, seeds, and stories about how the stalks seem to grow taller each night.