Annuals: Sunflowers for the Home Landscape from PlantsGalore.Com

Sunflowers are grown in home gardens for a number of reasons. They are ornamental and present varying sizes and colors of flowers. They also produce seeds which are nutritious and tasty for both humans and birds.

Commercially, a limited acreage of non-oil type sunflowers has been grown for years. Seed of this crop has been used primarily for bird seed, but may also be used for human consumption when whole roasted or as nutmeats. The oil seed type is used as a source for vegetable oil and high protein meal for livestock.

The sunflower belongs to the Asteraceae (formerly Compositae) Family and is in the species Helianthus annus. It is a native to America.

Sunflowers can be grown on a wide range of soil types. They do well on land that produces a good crop of corn. Sunflowers tend to be drought tolerant so that yield reductions under moisture stress tend to be less than with other crops. They will generally do better on medium to fine textured soils (loam, silt loams and clay loams) than on coarse textured soils (sandy loams and loamy sands).

Although they are drought resistant, their greatest need for adequate water comes during the 3 week period from the time the flower begins to develop until the head is fully formed. If natural rainfall does not provide an inch of water per week during this period (late July to early August) supplemental irrigation should be applied.

Young sunflower plants are generally tolerant of early spring frosts. They have been known to survive temperatures into the low twenties. This resistance is gradually lost, however, as the seedling continues to develop. By the 6 to 8 leaf stage, temperatures slightly below freezing may injure the crop. Sunflowers might be considered for production on muck soils because of this tolerance to frost in the seedling stage.

Disease problems can be reduced by not growing sunflowers in the same location for more than 3 or 4 years in a row. Many varieties have limited resistance to diseases such as Verticillium wilt, downy mildew and rust. These problems may build up in crop residues or in the soil and increase in severity when the same crop is planted in the same location for many years.

The major diseases of sunflowers are downy mildew, rust, Sclerotinia stalk and head rot, Verticillium wilt, Phoma black stem and Alternaria leaf and stem spot.

Insects that attack sunflowers include sunflower head moth, banded sunflower moth, and the sunflower weevil.

A number of birds will eat sunflower plantings but blackbirds seem to be the most damaging.

Note: We have provided some general information and observations on this topic aimed at the home gardener. Before you take any serious action in your landscape, check with your state's land grant university's Cooperative Extension Service for the most current, appropriate, localized recommendations.