Sunflowers are a colorful garden addition. These vibrant, fast-growing flowers can be food sources for people, wildlife, and pollinators. Sunflowers come in various shapes, sizes, and bloom colors.
Heights vary from 2 to 15 feet. Blooms start from 70 to 120 days after planting.
Branching cultivars, such as the Mexican sunflower, produce many blooms over time and get quite large, requiring space to flourish. Plant at least 18 to 24 inches apart.
Pollenless or “pollen-free” cultivars don’t contain the bright yellow pollen that can stain clothing. They are used primarily as cut flowers or garden plants. Heights range from 2 to 8 feet with a variety of flower colors and forms.
Dwarf cultivars are used in limited spaces or containers. Due to their small size of 3 feet or less, these cultivars are placed toward the front of beds or along borders.
Between 3 to 8 feet in height, semi-dwarf cultivars do not usually require staking. Semi-dwarf cultivars work well in landscape beds or borders.
Giant cultivars (over 8 feet tall) require staking due to their size in height, flower, and seed head. Spacing 2-feet apart ensures good air circulation for these.
Large seeds make sunflowers planting easy. Seeds germinate in 7 to 10 days. After frost, stagger plantings by a couple weeks to extend blooming. Seed no deeper than 1 inch; no closer than 6 inches apart.
Sunflowers enjoy full sun, at least 6 hours, and slightly acidic (6.0 to 6.8 pH), well-drained soil. They prefer sandy loam soils. Soil testing helps determine nutritional needs.
Regularly watering young plants creates strong roots helping sunflowers withstand wind and heat. One inch of water a week is needed. Control weeds with cultivation or mulch. Fertilize as needed. Cut flowers early in the morning for bouquets to avoid wilting.
Sunflowers have few pests—birds, deer, stink bugs, aphids, caterpillars, and occasional fungal infections. Deterrents and healthy plants prevent and control pests.
Common cultivars:
Large — Titan, Cyclops, Mammoth Russian, Mammoth Grey Striped, American Giant
Semi-dwarf and dwarf — Teddy Bear, Sunspot
Fall colors — Autumn Beauty, Crimson Queen, Evening Star, Ring of Fire
Cut flower — Sonja, Jade
By Brandy Brabham, WVU Extension Agent – Roane County