Growing and Harvesting Sunflowers

Sunflowers are perhaps the most cheerful and endearing native flower in the United States. For centuries, Native American tribes have harvested these versatile flowers for a variety of nutritional, medicinal and spiritual purposes. Today, they are grown on virtually every continent in the world. Here are some helpful hints for growing and harvesting your own.

Easy-to-Plant & Grow

Sunflowers are one of the easiest garden crops to grow. They tolerate most soil types and their roots grow deep and spread wide, giving them the ability to withstand a fair amount of drought as well as tolerate any soil disturbance brought about by the cultivation of nearby crops. Seeds come in a variety of colors including black, white, red and black and white striped. Start seeds indoors in 4-inch peat pots or sow them directly into the soil. Plant them in a sunny position in soil that affords adequate drainage and has warmed to at least 45º F (preferably above 50ºF). For plant to develop fully flowering heads, avoid fertilizers high in nitrogen.

When purchasing seeds, keep in mind that most commercial varieties of sunflowers seeds are hybrids. This won't make a difference when consuming the seeds, but if your planning on collecting seed for future stock, look for heirloom varieties instead. Seeds should be planted at a depth of 2 inches and spaced 12 inches apart in rows spaced 24 inches apart. Tall varieties or those with extra large heads will need more space. Germination occurs quickly, usually within 7-10 days (often sooner). Most varieties reach maturity in 80-90 days.

The twenty-day period leading up to harvest is the most critical time in the development of sunflower seeds. Avoid placing water stress on plants during this time (either too much or too little) and keep soil moisture levels as consistent as possible.

Pests & Disease

Common Diseases: Watch for verticillium wilt, downy mildew, rust and white mold. As with most garden diseases, prevention is the best medicine. Good sanitation and cultivation techniques (e.g. crop rotation) will go along way toward warding off potential problems.

Non-Insect Pests: Birds and Squirrels love sunflower seeds as much as the gardeners that grow them. Because sunflower seeds mature right around the time these critters are gearing up for fall, your sunflower crop can quickly become ransacked if not protected. Cover sunflower heads with nylon stockings, cheesecloth or paper bags to make robbing the seeds more difficult. Avoid growing your sunflowers near fences or low buildings that offer quick access to squirrels.

Insect Pests: Sunflower moths (the larvae), aphids and white flies are the primary insect pests to watch out for. Sunflowers need bees for pollination, so the use of chemical insecticides isn't recommended. Aphids and white flies can usually be kept under control by periodically spraying your sunflowers with a strong jet of water. Delaying planting until late May or early June will reduce the likelihood of sunflower moth problems.

Drying Flower Heads

To dry heads for floral displays, cut the heads (with the desired portion of stem attached ) just as they are starting to open. The heads will continue to open as they dry. Bind the stems together with a rubber band or soft string and hang them upside down in a warm, dark room to dry.

Harvesting Your Seeds

Seeds can be harvested while green or allowed to remain on the plant to ripen. Regardless of the variety, most sunflowers will tell you when their seeds are ready to be harvested. Their heads will stop tracking the sun and start bowing to the ground, the backs of their heads will turn a light yellow color, the florets in the center of the head will start to shrivel and when cracked open, the seeds will be plump with meat.

Cut off heads along with a portion of the stems and hang them upside down to try. Cover the heads with paper bags or cheesecloth to catch any falling seeds. When seeds are dry, simply scrape them away from the head with a knife, or thrash them onto a sheet.

Roasting Your Seeds

To prepare seeds for roasting, cover unshelled seeds with a solution containing 1/4 to 1/2 cup of salt in 2 quarts of water and allow them to soak for 24 hours. Drain and spread out on an absorbent material to dry. Roast sunflower seeds on a cookie sheet or in a shallow pan at 300º F for 30 to 40 minutes or until golden brown. Optional: Add one teaspoon of butter to 1 cup of roasted seeds and salt to taste. Seeds intended for animal food can be stored immediately after drying in an airtight container.