Posts Tagged how to grow sunflowers

How To Grow Sunflowers

How To Grow Sunflowers

      How To Grow Sunflowers    

Charles T. Behnke

Sunflower is the common seed name for the genus Helianthus. The sunflower is native to North America, and was used by early North American Indians for food and pressed to make hair oil. Meal from processed seed has been used for livestock feed. Today, whole seeds are used for oil, bird seed and snacks. The seeds are a rich source of calcium plus 11 other minerals. The 50 percent fat composition is mostly polyunsaturated linoleic acid.


As a garden plant, the sunflower is valuable for forming a background screen. A rapid grower, it reaches a height of 8 to 12 feet in rich soil.

This rapid growth could cause competition with other garden plants, especially by shading. Sunflowers can be planted between groups of shrubs, particularly where these form a background. For smaller gardens, the multi-branched species are more suitable. Dwarf forms of 24 inches in height make a spectacular bed by themselves.

When growing sunflowers for bird food or human consumption, select the confectionery types over the oil types.


Sunflowers do best when grown on soils with adequate water-holding capacity, internal drainage and proper fertility. They will tolerate a wide range of soil types; however, one that is too high in nitrogen encourages excessive plant growth that will check maturity of the flower heads. Adequate levels of phosphorus and potassium are recommended, and, as with any garden activity, frequent soil tests are recommended to get good results. The plant’s roots go deep and spread extensively, so the sunflower can withstand some drought and nearby cultivation. Sunflowers should not be water stressed during the critical period; about 20 days before and after flowering.

Plant seed into moistened soil one to two inches deep, but no deeper than three inches. Space seed 12 inches apart in rows spaced 2 to 2 1/2 feet apart. Plants grown for large heads should be spaced farther apart or scattered around the garden.

In Ohio, planting can take place from early to mid-May. Seed bed soil temperature must be between 42 and 50 degrees F with temperatures above 50 degrees F preferable for germination to occur rapidly. Depending on variety and environmental factors, germination will occur in 7 to 12 days. Plants will mature in 80 to 90 days.

For the home situation, seed can be started in four-inch peat pots and transplanted outdoors. Transplants may grow taller and flower sooner than seed started plants. They should start to flower in ten weeks.

Weeds can be a problem for sunflowers. Weed control is practiced for the first four to five weeks after seed emergence. For the home garden, hand weeding and mulching are the best methods.

Diseases and Pests  

A common disease of sunflowers is Sclerotina or white mold, which causes stalk and head rots. Disease spores can live for many years in the soil. Other common diseases are downy mildew, rust and verticillium wilt. Sanitation and crop rotation should be considered for control in the home garden.

The sunflower head moth is the major insect pest. The moth attacks at flowering time with the larvae feeding on floral parts and tunneling through developing seed. Aphids and whiteflies also can be a problem.

Birds can be troublesome near harvest time. Seeds are exposed and the large flower head serves as a feeding perch. To deter birds, use frightening devices and human activity in the immediate area before damage is expected. Flower heads can be covered with plastic netting or cheesecloth.


Harvest begins in mid-September and can run into October. A check of the flower head will indicate maturity; florets in the center of the flower disk are shriveled, heads are downturned, and a lemon yellow color is on the backside. Pull a few seeds and split them with a knife to check if seed meat has filled. Poorly filled seeds may be due to a lack of pollinating insects.

To harvest, cut the seed head with about a foot of stem attached and hang in a warm, dry, well-ventilated, rodent and insect-free place. A paper bag with holes or cheesecloth can be placed over the heads to catch falling seeds as they drop during drying. Seed heads can be allowed to ripen on the plant, but cheesecloth or nylon netting will be needed for bird protection. Once the seed is dried, it can be rubbed easily from seed heads. Humidity levels must be kept low to prevent spoilage.

Roasting Seeds

Raw mature seeds may easily be prepared at home by covering unshelled seeds with salted water (2 qts. of water to 1/4 to 1/2 cups salt). Bring to a boil and simmer two hours or soak in a salt solution overnight. Drain and dry on absorbent paper.

Put sunflower seeds in a shallow pan in a 300 degree F oven for 30 to 40 minutes or until golden brown, stirring occasionally. Take out of oven and add one teaspoon of melted butter or margarine to one cup of seeds. Stir to coat. Put on an absorbent towel. Salt to taste.

Sunflower Species

Common Sunflower (H. annuus) – Includes the cultivars H. bismarkianus‘s, single yellow flower, 6 to 8 feet tall; H. citrinus, primrose yellow flowers, 6 to 8 feet tall; H. giganteus, Russian Giant, large, single yellow flower grown mainly for seeds, 10 to 12 feet tall.

Silverleaf Sunflower (H. argophyllus) – Stems and leaves covered with silky gray down, especially on younger growth. Flowers golden with purplish brown center, plants 5 to 6 feet tall. Silvery leaves used in fresh and dried flower arrangements.

Cucumberleaf Sunflower (H. debilis) -Four-foot plants with multiple branches. Excellent for cutting. Three-inch flowers have a purple disk and yellow rays.

Ohio State University Extension Fact Sheet Horticulture and Crop Science 2021 Coffey Rd., Columbus, Ohio 43210-1086



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Anyone Can Grow Sunflowers!

Anyone Can Grow Sunflowers!    


By Brenda Hyde of Old Fashioned Living

Sunflowers are easy, and inexpensive to grow, and yes, everyone can do it! The days of sunflowers being contained to the vegetable garden are over. There are now varieties that can be grown in large pots and containers, as well as corners of your yard or garden. Children of all ages love sunflowers and can participate in choosing the variety, planting and harvesting.

The Basics

These are the basic technical tips you need to know about Sunflowers, or Helianthus Annus (their official name).

  • Plant in full sun, where they will not shade other plants.
  • Be sure to plant after the last frost in your area.
  • The seeds should be 1 inch deep and 6 inches apart when planted.
  • When the seedlings pop up, thin them to 1 1/2 foot apart or one foot for the dwarf varieties. (In containers you can squeeze them closer)
  • Water well after planting.

Choosing Your Sunflowers

Children can be involved in every aspect of your sunflower garden. You can guide them in choosing the seeds. These are just a few of the options you will have.

Teddy Bear:

This variety has a full, almost “fuzzy” look and grows only 18 inches tall. You can plant this type in patio boxes or large pots. If you are in an apartment or limited on space this is perfect!

Music Box:

This is also considered a dwarf variety at 28 inches. You can buy a mix of this, so you end up with yellows and creams. This is also a wonderful container sunflower.

Autumn Mix

The colors are yellow and rust; they grow tall, usually over 6 foot. We grew them in a very small corner off our porch and were able to use twine and tie them for support. The gold finches loved this variety. The flower heads are about 5 or 6 inches wide.

Italian White:

These cream colored sunflowers are small, but cheerful. They grow up to 4 foot tall, but stake easily. The gold finches also loved this variety. These too are great for a small corner of your yard or garden.

Large Varieties:

You will have many large varieties to choose from. Russian Giants grow 20 inch seed heads and the Kong Sunflower grows 10-15 foot tall. You will need more space for these, but they are worth it!

Planting Your Seeds

Using the tips above, plant your seeds after the last frost. The children can easily do this with a ruler, and a gardening spade or large spoon. Any soil will work, but a well drained soil with peat added is a better choice. Have the kids dig a bag of peat (very inexpensive)into the area you will be planting in. For the giant sunflowers, a strip of soil, about 1 1/2 to 2 foot wide or wider is great, especially against a fence where they can be tied to protect against the wind. Don’t be afraid to experiment! If you have a spot that needs something cheerful, then use it! Another project for the kids, with your help, is drawing out the area you will planting in and laying out the steps involved. This can be done ahead of time to get them excited. Remember that you don’t have to plant the entire packet of seeds, or limit yourself to one large area. Using several small corners or strips of soil works well.

Growing and Harvesting

Sunflowers will pop out of the ground in a week to two weeks, and will start out slowly. If you notice birds or other animals bothering the little seedlings you can tent a piece of chicken wire, a milk jug with the top and bottom cut off or something similar to protect them. They will pick up speed in their growing process, and the children can be responsible for watching them, watering them, and placing cut up leaves or another type of mulch carefully around the bottoms of each plant.

Many people harvest all of the sunflowers and don’t allow the birds to feed. I think for children, a nice alternative is to cover some of the heads with cheesecloth, mesh bags or old pantyhose, so you can roast the seeds later, but leave the other flowers for the birds. The children can record which birds come to the plants and how many, as an extra project.

When the seed heads start to turn brown, they can be cut with 2 inches of the stem and hung to dry in a ventilated place such as a garage or attic. When they are dry, simply rub them together to loosen, soak over night in salted water and then drain. Spread them on baking sheets and roast for three hours at 200 degrees until dry. These can be stored in a container for eating. Be sure to save some seeds out before this process, place in envelopes and label for planting next year. Store them in a dry cool place until spring.

Growing sunflowers can be a unique, family project. So much can be learned about nature and the growing process, as well as teaching children patience. The end result will be something they will always remember and treasure.

Brenda Hyde is a freelance writer, wife and mom to three living in the Midwest. She is also editor of, where you will find articles on gardening, herbs, crafts and other old fashioned topics.

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