The best place to plant sunflowers. This species is listed as a harmful grass in one or more Midwestern states outside Missouri and should not be moved or cultivated in conditions that would present a risk of spreading. Invasive: This species is invasive in the US
Culture
Grows well in moderately moist, well drained soil in full sun. Tolerates bad soils and can be on the dry side.
Plant seeds in the garden after the last frost date. If the plant grows well, there is little reason to plant seeds indoors.
Tall varieties should be placed in sheltered locations. Foliage of plants will decrease during the summer.
Removing brown, tattered plants before the garden blooms may improve the appearance of the landscape, but it is a major disappointment for the local bird population, which relies on seeds for its food. If the plant falls, consider saving the seed heads to feed them to the birds in winter. The harvest of seeds from a favorite plant can be used the following year, if the variety does not arise from seeds.
Noteworthy Characteristics
Helianthus annuus is a hairy, leafy, slow growing annual that grows to 5 to 10 meters tall and has stiff, upright stems. It is native to the dry plains, prairies, meadows and foothills of the western United States, Canada and northern Mexico. Helianthus is a weed plant that grows along roads, fences, fields and fallow land along the Mississippi River and in Kansas State. This plant is also native to Missouri, especially in the northern part of the state.
Extensive crossbreeding and hybridization has resulted in a large number of varieties with an ever-growing palette of flower colours and rays, with blossoms in bright pastel tones of yellow, red, mahogany, bronze, white and bicolour, and flower heads with short and long rays that double. Dwarf varieties are 1-3 “tall, while mammoth varieties are up to 15″ large and widespread. The flower heads of mammoth varieties can reach a diameter of 12. ” Some species of the plant have 3-6 “wide sunflowers with orange or yellow rays and brown or violet central discs.
The genus name derives from the Greek word helios for “sun” and anthos for “flower.” Large egg-shaped or triangular sandpaper leaves, up to 12. The disc flowers give way to the familiar sunflower grain. Sunflowers have become popular as commercial cut flowers around the world. Cultivated varieties are cultivated for their edible seeds, which are used, among other things, as animal feed, bird feed and cooking oil.
Specific epithet means annual.
Flowerheads tend to follow the path of the sun every day, from morning to evening, hence the common name.
Problems
May need to be staked out, especially if grown in exposed locations. Rust on the leaves, fungal stains and mildew are common. Caterpillars and beetles chew through leaves.
Uses
Dwarf varieties for beds, borders, fronts or containers. Limit a house, bird, wildflower or native plant garden. Larger varieties line the back or the background.
