How to Grow Sunflowers

Bright, cheerful sunflowers look beautiful in the yard and garden, and make wonderful cut flowers.

  • Plant in a sunny location with moist, well-drained soil.
  • Prepare the existing soil by adding Miracle-Gro® All Purpose Garden Soil.
  • Sow seeds directly in the garden when the soil warms up in the spring.
  • Water seeds at the time of planting and regularly throughout the growing season.
  • Feed sunflowers with Miracle-Gro® Water Soluble All Purpose Plant Food, starting a month after planting.
  • Stake sunflowers if they have multiple branches or heavy flower heads.
  • Prevent pests from digging up newly planted seeds and from eating seed heads you hope to harvest.
  • Harvest flower heads when the back has turned black and the seeds have dried out.

Sunflowers are such a colorful and whimsical addition to every garden. They're easy to grow from seed and make excellent cut flowers. 

There are hundreds of different varieties of sunflowers, including perennial varieties that come back every year. Home gardeners most commonly plant annual varieties (which last only one growing season), including both dwarf and tall varieties with multiple branches and dozens of blooms (perfect for cutting). The types of sunflowers grown especially for seed harvesting also fall into the category of annual flowers. You can find sunflowers with flower colors ranging from pale lemon yellow to orange, pink, burgundy, and bright yellow. There are also bi-color and multi-color varieties. 

No matter which you choose, let us teach you how to grow sunflowers for weeks of gorgeous flowers.

Where to Plant Sunflowers

Sunflowers grow best in full, bright sun, and in evenly moist, well-drained soil. The amount of space they need depends on which varieties you are growing. Branching types with multiple blooms on one stem need more space horizontally than large single-flowered types. Take care to select a spot to grow taller varieties where they won’t throw too much shade on other shorter, sun-loving plants. The north side of a flower border is almost always a good spot.

When to Plant Sunflowers

Sunflowers are warm-weather plants. You can plant sunflowers outside at the same time you plant peppers, tomatoes, eggplants, zinnias, and other warm-season vegetables and flowers. For a longer sunflower bloom period, plant a row or grouping of sunflowers every two weeks for four to six weeks during the early summer. 

How to Prepare the Soil for Planting Sunflowers

Make sure your plants get off to the best start! Prepare new in-ground planting areas with Miracle-Gro® All Purpose Garden Soil, mixing 3 inches of garden soil into the top 6 to 8 inches of native soil. This will feed new plants and help build strong roots, both of which will mean big, beautiful blooms! Of course, your best path to sunflower success comes from a combination of great soil and just the right plant food, so be sure to read the "How to Feed Sunflowers" section below.

How to Plant Sunflowers

While you can start sunflowers from seed indoors, it’s just as easy to grow them from seed outdoors. Plant sunflower seeds directly into the garden when the soil is warm—at least fifty degrees Fahrenheit. Use your thumb to push seeds 1 to 2 inches deep into the soil. Depth and spacing depends on the variety, so read the instructions on the seed package. 

How to Water Sunflowers

Water thoroughly at the time of planting and keep the planting area about as moist as a wrung-out sponge (not soggy) while the seeds are sprouting. Most sunflowers are fairly drought-tolerant once established, but will bloom better with regular water. To be on the safe side, water sunflowers well when the top two inches of soil are dry. 

How to Feed Sunflowers

While sunflowers are not big feeders, you will get more and better blooms if you make sure they get a steady stream of nutrition. A month after planting, begin feeding sunflowers with Miracle-Gro® Water Soluble All Purpose Plant Food. Make sure to follow the directions on the package.

How to Stake Sunflowers

Whether or not you need to stake your sunflowers depends on how tall they get, the strength of the stems, and the branching pattern. If you’re growing a bunch of sunflowers for cut flowers, you can plant the seeds and then create a latticework of stakes and twine for the plants to grow up through. Create two rows of staggered stakes with 3 feet in between each stake. Run twine around the stakes to create a wide lattice. You can also stake individual plants that are beginning to droop by placing a sturdy stake 3 inches from the plant stem and tying the stem to the stake, loosely, with twine in a couple of places.

How to Avoid Pest Problems with Sunflowers

Squirrels and chipmunks can be a problem when you first plant sunflower seeds, as they love to dig them up and eat them. Shake some ground cayenne pepper on the ground around where you’ve planted the seeds. If that doesn’t deter them, try starting seeds indoors and then planting them outside once they have sprouted. If you’re growing sunflowers for seed, these pests can be a problem near the time of harvest as well. When the outer petals dry up, cover the large flower heads with lightweight cloth tied around the stem. 

How to Harvest Sunflower Seeds

Cut the large flower heads off when the back of the large flower disk has turned black and the seed heads are dry. Leave in a cool, dry place for a few days to completely dry out, and then remove the seeds by gently rubbing the flower heads with your thumbs. Keep dried seeds in a breathable paper or cloth bag to prevent mold growth.

Ready to start growing sunflowers? Click on any of the product links above for more information, to purchase the product online, or to find a retailer near you.

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