How to Grow Sunflowers

Sunflowers are often grown for their ornamental value but their seeds can be harvested and they make great cover crops and feed for birds and livestock as well. What’s more, they can be grown by just about anyone in almost any environment. Check out these instructions on how to grow sunflowers.

Sunflowers come in a surprising number of varieties. Some can grow as large as 15 feet tall, while others will grow only about 1 foot. Try ‘Autumn Beauty’ for its gorgeous 6-inch flowers that will be bright yellow, bronze and mahogany. ‘Mammoth’ is the traditional, behemoth sunflower grown for its towering ornamental quality as well as the edibility of its seeds.

Sunflowers grow best over the course of a long, hot summer. Plant them after the danger of frost has passed in the spring and once soil temperatures are 55° F – 60° F.

Sunflowers can be grown anywhere with enough frost-free days to reach maturity but prefer hot weather. They should be planted in the full sun in a place that’s protected from strong winds, particularly if you are growing the taller varieties. Grow sunflowers near a fence to protect from winds and provide support if necessary.

Sunflowers will grow in any type of soil that has good drainage, but prefers sandy loam. Amend the soil with mature compost or enrich with fertilizer prior to planting. Fertile soil will help the roots to grow strong and deep, lessening the risk of toppling sunflowers. The pH can be relatively wide: 6.0 – 7.5.

Sow sunflower seeds 1 inch deep and 6 inches apart. Keep the soil moist during germination. Thin seedlings to 1-2 feet apart once they reach 6 inches tall. Give more space to the larger, taller varieties.

Sunflowers like deep, infrequent waterings. This will ensure deep rooting.

Provide a layer of organic mulch around the base of each sunflower plant. This will keep weeds down and help to preserve moisture in the soil.

Some tall varieties of sunflowers will benefit from the support of a stake or fence, particularly if their heads become larger than their stems can handle. Watch for droopy flowers as they grow tall.

Sunflowers shouldn’t need fertilizer if planted in fertile soil. In fact, too much feeding can cause the stems to break once they get too tall and top heavy.

Birds, squirrels and deer will often feast on sunflowers and their seeds. Netting and fencing are often your best option if they become a problem. Insects usually do not pose a problem to sunflowers. In fact, sunflowers tend to attract beneficial insects like bees and butterflies to the garden.

Sunflower seeds are ready for harvest once the bracts begin to dry out. The seeds will begin to turn brown and the back of the flower heads will turn yellow and sag. Cut them off with 2 inches of stem and hang in a dry, well-ventilated place that is protected from pests like mice and birds.

Dried sunflowers can be fed to birds and animals as they are. For human consumption, soak the seeds in water (or salt water for a salty taste) over night. Drain the water and bake them at 200° until crisp, which usually takes about 3 hours. Store sunflowers in an airtight container.

Sunflowers can provide nice shade to vegetables that need it, but avoid planting them near vegetables that need full sun.

In short season regions, choose cold-resistant varieties and plant them a few weeks before the last frost of winter.

Sunflower petals can be used to make dye.

Grow sunflowers with pole beans and train the bean vines to grow up them.

Do you have questions or tips on how to grow sunflowers? Let us know in the comments section below.

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