The Best Time to Plant Sunflowers Is Coming Up Quickly and You Don’t Want to Miss It

Sunflowers (Helianthus annuus) are annuals, meaning they must be planted each year. To ensure a continuous supply of blooms all season long, people often succession plant sunflowers.

Additionally, to get a jump on the season, sunflower seeds can be started indoors in late winter/early spring, using biodegradable pots and grow lights. Make sure to harden off seedlings before planting them in the garden.

When Should Sunflowers Be Planted?

Typically, sunflower seeds are planted in early to late spring, depending on the temperature in your growing zone. You’ll know when to plant sunflowers once the soil temperature reaches at least 55°F to 60°F and all danger of frost has passed.1 Plant sunflowers around two to three weeks after the last expected frost date for your growing zone.

Some sunflower varieties germinate at soil temperatures between 70°F and 85°F, but seeds can be planted when the soil hits 60°F. You can check soil temperature by sticking an instant-read thermometer in the soil or by consulting your local cooperative extension office.

How to Plant Sunflower Seeds

With their large seeds, sunflowers are easy to direct sow.

1. Choose a spot with slightly acidic, well-drained soil and full sun (at least eight hours) to plant sunflowers. Work organic compost into the soil a few weeks before you plan to plant.
2. Check the seed packet for the spacing and mature size of the sunflower variety you chose to determine spacing. In general, sunflowers under 5 feet tall should be planted at least 6 inches apart, with taller varieties 12 to 15 inches apart. Plant giant sunflower varieties, which can grow up to 15 feet in height, at least 2 feet apart. Space rows at least 2 feet apart.
3. Direct sow sunflower seeds 1 inch deep. Do not plant too deep, or seeds may rot and not germinate.
4. Water sunflower seeds regularly for the first week or so to support good germination, which typically takes one to 14 days. After that, make sure your sunflowers get at least an inch of water per week throughout the season.
5. Plant additional successions of sunflowers every week or two to enjoy blooms later in the summer.

Top Varieties to Grow

The best variety of sunflowers to grow depends on how much space you want to devote to the plants in your garden. Dwarf varieties, which grow shorter than 3 feet, are ideal for small spaces, container planting, and borders. Semi-dwarf varieties grow to between 3 and 8 feet tall, while giant sunflowers grow at least 8 feet tall.

Another consideration is color. While the classic sunflower has a brown center surrounded by rich yellow petals, sunflowers are also available in shades of red, yellow, orange, white, pink, and brown. There are newer branching varieties that offer continuous blooms throughout the season.

Or, if you enjoy using sunflowers for flower arrangements, you may want to consider pollen-free varieties to keep your dining room table clean. Here are some of the top sunflower varieties to plant in your garden.

• Teddy Bear: This compact dwarf variety with double orange petals and a tiny green center is a great option if you don’t have much room for sunflowers.
• Elf: Thought to be the shortest sunflower available, this pint-sized variety maxes out at 16 inches tall, making them perfect for cheering up a window box or other small planter.
• Chocolate: Named for its deep reddish-brown petals and dark brown centers, this semi-dwarf variety adds contrast to brighter colors while hitting 4 to 5 feet tall at maturity.
• Italian White: These semi-dwarf sunflowers are known for their pale, cream-colored petals, which pop against small, deep-brown seed heads. They’ll grow to between 4 and 6 feet, making them a versatile option for flower gardens and backyards.
• American Giant: With heights of up to 14 feet, this stunning giant variety is one of the tallest out there. Its massive flower heads measure up to 1 foot across.
• Russian Mammoth: With its huge, golden-hued flowers and 12-foot height at maturity, this giant sunflower is excellent for creating a colorful privacy screen.