The expression sunflower (Helianthus annuus) generally conjures up images of towering plants with dinner-plate-size heads, bright yellow petals and dark centers. These yearly sunflowers work well in the backs of gardens or as a privacy screen. New varieties of sunflowers produce numerous blooms on branching stalks and comprise a range of colors — from conventional yellow to rich shades of maroon, red and chocolate. The height of sunflowers depends on the variety grown, but there are a few general guidelines for expected stature.
Giant Sunflowers
These huge plants reach heights of 10 to 20 feet, creating an impressive display of colour in the yard or garden. The Guinness Book of World Records reports the tallest sunflower ever climbed measured 26 feet 4 inches. Even though it’s unlikely your giant sunflowers will reach a record-breaking height, they’ll tower over other flowers in your garden.
Medium-size Sunflowers
Typical sunflowers reach heights of 5 to 10 feet when grown in full sunlight and provided adequate moisture and care. Size and shape varies from several different branching to single stalk, with bloom size ranging from a few inches to a foot or more in diameter, depending on the range. Colours run the gamut from almost white to deep hues of crimson, orange and yellow with many bicolors.
Dwarf Sunflowers
Dwarf sunflowers range in height from 12 to 36 inches in height. These miniature versions typically make 3- to 5-inch blooms in a range of colors, making them suitable for container gardens or perched on the deck or patio. Blooms may be only for double blooms.
Considerations
Tall or giant sunflowers typically require staking or planting against a wall or fence to provide them with needed support. Even though they may be striking, they do need more time and care. Medium-sized sunflowers typically do nicely without staking and create brilliant blooms in late summer or early autumn. Dwarf sunflowers provide the beauty of sunflowers with very little care, apart from consistent watering. All sunflowers follow the course of sunlight when they’re young and typically face east when they bloom. Planting them around the northern or western side of the property lets you see them when in bloom.
Cultural Needs
Irrespective of their size, sunflowers prefer a sunny location that receives six to eight hours of direct sunlight every day. Even though they will tolerate nearly any soil, they prefer evenly moist, fertile, well-drained soil with a pH between 6.0 and 7.5.