Colors range from traditional yellow petals with a brown center to gold, orange, coppery-red or maroon. Sunflowers have become particularly an autumn favorite … perhaps because they bring back memories of colorful falling leaves and fat orange pumpkins from the past.
The familiar Annual Sunflower (Helianthus annuus) is a native of the central United States into South America. In some areas it grows so well that it is considered an invasive weed. There are endless forms and cultivars, including those with short stems, long stems, large and small flowers, a multitude of colors and combinations of colors, with multiple heads and singles. The medium-sized flowers have become favorites of the cut-flower industry.
Recognized worldwide for its dazzling beauty, Annual Sunflower is also an important food source. The oil has a low level of saturated fats and can withstand high cooking temperatures, so is a valued light vegetable oil. Its high-energy seeds are enjoyed as a healthy and tasty snack for people and birds. Most seed-eating songbirds prefer Sunflower over all other seeds.
Oil extracted from the seeds is used for cooking, production of margarine, and making bio-diesel fuel. It is understandable that these plants have become a preferred crop for farmers from the northern plains to the Texas panhandle. The seed is commonly planted in early spring in sunny and well-drained, fertile soil. Maturing from 2 to 10 feet high with up to a 4 feet spread, hybrids now dominate available varieties.
Maximillian Sunflower (Helianthus maximillianii) is one of more than 38 species of perennial Sunflowers native to North America. These robust sun-tolerant plants with their brilliant yellow flowers can spread fast so need lots of space. Started by division or seed, they grow rapidly, forming large clumps that can become invasive in small spaces. Bloom occurs in late summer through autumn. Flowers are generally smaller, averaging 3 inches diameter; but the quantities will cover the foliage at peak bloom.
Growing in clumps of 4 to 8 feet high and wide, Maximillians are considered drought tolerant. However, experience at The Arid Garden has found that these plants wilt in summer’s high temperatures unless watered daily. Being perennials, they need to be divided every few years to maintain their vigor and profuse bloom. This plant is a good choice to highlight a wall, provide a colorful background, or accent a corner of the landscape.
Early civilizations worshipped Sunflowers by placing their images made of gold into temples and crowning rulers with the bright flowers. We need only plant the seeds in spring, watch them grow during summer, and be ready to enjoy the brilliant autumn blossom colors!
Mary Kidnocker is a University of Arizona Master Gardener who lives in the Green Valley area. Her articles are featured weekly.