Sunflowers stop blooming during periods of drought, so watering them regularly is recommended. It is very important that sunflowers receive full sunlight. Sunflowers are able to grow in most soils, but sturdier, loamy soil yields healthier plants.
Although regular watering is necessary, too much water can be harmful. If the soil becomes too moist, it may not be able to support the sunflower's heavy head. Planting sunflowers in groups can stabilize them and protect them from wind damage. Group planting also prevents the sun from drying up the soil prematurely.
SunflowerGuide recommends stabilizing tall sunflower plants by securing them to a post or stake with a florist tie, a piece of thick string or velcro. It is important to make sure that the securing material does not cut into the stem when the plant sways in the wind.
Although sunflowers generally do not require pruning, it can be beneficial to cut down plants that are leaning on others. One single leaning flower can damage multiple flowers at a time, so SunflowerGuide recommends removing problematic sunflowers to protect the group.
Sunflower seed shells are toxic to grass, so the sunflower heads need to be harvested before seeds get a chance to fall onto lawns. This should be done in early summer.