Sunflower planting dates by zone

Choosing a sunflower

University of Illinois Extension says sunflowers range from 6 inches to more than 12 feet tall, in yellow, orange, red and maroon, with one flower per plant or dozens on a branching plant. University of Minnesota Extension sorts them into dwarf cultivars of three feet or less, for the front of beds and containers; semi-dwarfs between three and eight feet that usually need no staking; and giants of eight feet or more that sometimes do.

Pollenless cultivars are grown mainly as cut flowers, and Minnesota says they do not drop the yellow pollen that stains clothing. Illinois notes that pollen-less types give pollinators such as bees little to eat, so choose pollen-bearing ones if bees are the point.

Sowing and planting out

Minnesota direct-seeds sunflowers after all danger of frost has passed, and Illinois sows them directly after the danger of frost, early to mid-May in Illinois; NC State Extension says to plant by seed after the last frost in spring. The table above gives that date for your zone. Illinois says they can also be started indoors 2-3 weeks before planting outdoors, but they do not like their roots disturbed.

Minnesota leaves about 6 inches between plants of varieties 2 to 5 feet tall, at least 1 foot between taller ones and 2 feet between giants, and 18 to 24 inches for branching types. It says sunflowers do best in slightly acidic soil, pH 6.0 to 6.8, and Illinois that they grow in a wide range of soils as long as the site is sunny and not consistently soggy.

Sowing in succession

Illinois sows every 1-3 weeks for a longer bloom. Minnesota gives three ways: sow several varieties with different days to maturity at once, sow them at three- to four-week intervals, or grow branching cultivars that bloom over a long period.

Mississippi State Extension’s Monroe County agent sows sunflowers every week from late March for blooms from May to first frost, and says most sunflowers bloom in about 50 days; the agent’s favorite, ‘ProCut Horizon’, matures in 50-60 days. Count back 60 days from the first frost date, the column says, to know when to stop planting; the table above does that count for your zone. The agent starts seedlings in trays because birds and mice dig up seed sown in the ground.

For fall flowers, Mississippi State’s Gary Bachman says most ornamental and cut-flower sunflowers flower about 60 days after planting, so in Mississippi seeds planted by Aug. 15 bloom from late September to October. Texas A&M AgriLife’s Larry Stein, in Uvalde, says it is not too late in May to sow sunflower seeds directly into the soil.

Care

Minnesota says sunflowers can withstand some drought, but to water them regularly 20 days before and after flowering, and that a side dressing of slow-release fertilizer once they have several true leaves gives larger flowers. Illinois says they thrive in low-nutrient soils, typically need little or no fertilizer, and that too much can reduce flowering.

Illinois says tall varieties with large heads can be damaged in high wind, so plant them in a sheltered spot or stake them; staking also keeps stems straight for cutting. NC State also recommends a sheltered location for taller varieties. Weeds compete hardest while the plants are young (Illinois).

Cutting sunflowers for bouquets

Illinois cuts sunflowers as the flowers begin to open, when the petals start to rise, in the morning, and cuts the stems at an angle so they take up water and do not sit flat on the bottom of the vase. Remove most or all of the leaves, especially any that would sit under water, and put the stems in clean water.

Southern timing

UGA Extension lists sunflower as a tender annual, from 24 to 120 inches tall, that needs well-drained, moist, rich soil for maximum growth, and its cut-flower guide says sunflowers tolerate sun, heat, drought and poor soils and are well suited to direct sowing. Mississippi State’s Monroe County agent says the growing season in northeast Mississippi is well over 200 days long, and stops setting out new sunflowers in early September.

Common problems

Illinois says powdery mildew can be an occasional problem in humid weather, so space plants properly, and names stink bugs, aphids, caterpillars and sunflower headclipping weevils, which rarely need managing. NC State adds slugs, snails and beetles, leaf spots and rust, and says sunflowers self-seed and can become weedy.

Minnesota says deer can destroy young plants and birds go for the seeds, and that sunflowers attract a great many beneficial insects and pollinators, which matters before reaching for an insecticide.

Common mistakes

• Sowing before the last frost. Minnesota and Illinois wait until the danger of frost has passed; NC State says sunflowers are not frost-tolerant.
• Transplanting roughly. Illinois says sunflowers do not like their roots disturbed.
• Over-feeding. Illinois says too much fertilizer can reduce flowering.
• Sowing too late for fall. Mississippi State counts back 60 days from the first frost.
• Growing pollenless cultivars for bees. Illinois says they produce little or no pollen.

We found no Florida, Louisiana or Alabama source for sunflowers that we could read, and the Texas source we read gives only that May is not too late to sow. The Southern timing on this page is Mississippi State’s and UGA’s.

Questions

When should I plant sunflower seeds?

Minnesota and Illinois sow after the danger of frost has passed, and NC State after the last frost. The table on this page gives that date for each zone from NOAA records, and the last sowing that still has 60 days to bloom before the first fall freeze.

How long do sunflowers take to bloom?

Mississippi State says most sunflowers bloom in about 50 days and that ornamental and cut-flower varieties flower about 60 days after planting on average; ‘ProCut Horizon’ matures in 50-60 days.

How far apart should sunflowers be planted?

Minnesota leaves about 6 inches between varieties 2 to 5 feet tall, at least 1 foot between taller ones, 2 feet between giants, and 18 to 24 inches between branching types.

When should I cut sunflowers for a vase?

Illinois cuts them as the flowers begin to open, in the morning, at an angle, and strips the leaves that would sit under water.

Can I plant sunflowers in late summer?

Yes, if there is time before the first freeze. Mississippi State counts back 60 days from the first frost date, and in Mississippi plants by Aug. 15 for blooms from late September to October.

Sources

Freeze dates on this page are NOAA 1991–2020 Climate Normals, for every station the ZIP codes in each zone cite. Zones are the USDA Plant Hardiness Zone Map, 2023. The planting rules are named beside the table. Growing advice is quoted from the extension publications below, each written for its own area.

• University of Minnesota Extension, Sunflowers (Reviewed 2026). Written for: Minnesota (USDA zones 3a–5a).
• University of Illinois Extension, How to grow sunflowers at home , by Ken Johnson (March 18, 2022). Written for: Illinois (USDA zones 5a–7a).
• University of Illinois Extension, Plant Sunflowers in Mid-May for Summer Beauty and Pollinator Power (April 30, 2025). Written for: Illinois (USDA zones 5a–7a).
• Mississippi State University Extension, How to sow sunflowers in successful succession (Southern Gardening) , by Kayla Dowden, Monroe County (March 20, 2023). Written for: Mississippi (USDA zones 7b–9a).
• Mississippi State University Extension, It is not too late to enjoy growing fall sunflowers (Southern Gardening) , by Gary Bachman (August 2, 2022). Written for: Mississippi (USDA zones 7b–9a).
• NC State Extension Gardener Plant Toolbox, Helianthus annuus (common sunflower) . Written for: North Carolina (USDA zones 6b–9a).
• UGA Cooperative Extension, Flowering Annuals for Georgia Gardens (B954) , by Bodie V. Pennisi (Published with minor revisions May 11, 2026). Written for: Georgia (USDA zones 7b–9a).
• UGA Cooperative Extension, Some of Georgia’s Best Cut Flowers , by Paul A. Thomas (March 5, 2026). Written for: Georgia (USDA zones 7b–9a).
• Texas A&M AgriLife Extension Service (Texas A&M Stories), How to keep your garden colorful through the summer (May 8, 2023). Written for: Texas (USDA zones 6b–10b).

How we write our guides

Published October 24, 2026