Top Field Selection Crop Rotation Sunflowers grow best on loam, silty loam and silty clay loam soils with good drainage. Sunflowers have a low tolerance of saline conditions, and therefore soils with moderate to high levels of salinity should be avoided. Sunflowers are sensitive to herbicide residues, such as Lontrel and Pursuit. Consult the product label or the current Guide to Crop Protection for specific details. Crop rotation when growing sunflowers is very important.
Sunflowers are very susceptible to sclerotinia as are canola and beans.
Refer to Section IV - Diseases for further details on all diseases and crop rotation. Seeding Treatments Seeds can be treated with a fungicide to control downy mildew, but there are no registered treatments for seedling blight. For specific seed treatment information, consult the current Guide to Crop Protection. Dates Sunflower seeding should usually begin anytime after May 1 and ideally be finished by June 1. Confection varieties are longer maturing than oilseed types.