Sunflowers are not only an attractive flower, they also have rich history providing edible seed crops. Sunflowers do best when planted directly in the soil, after night temperatures warm to above 50 degrees. As their name suggests, need plenty of sunlight (minimum of 6 hours per day). They will also turn their flower heads to follow the sun from east to west.
For giant sunflowers, make sure to chose an area in the yard near a fence or support structure. Sunflowers tend to become very top-heavy as seeds develop, sometimes pulling themselves over (credit anna). Watering sunflowers deeply but infrequently encourages deep root development (which will also help them stand upright). Sunflowers can also be utilized for shade and structure for other vegetables in the garden.
In order to keep birds and squirrels from helping themselves to sunflower seeds, paper bags, nylon mesh or nets can be placed over the flower heads. The best bet is to plant a few extra for wildlife to enjoy, and you to enjoy watching them.
Sunflowers tend to attract aphids, which will feed on the plant and cause some stunting. Instead of using a pesticide, which can harm beneficial insects such as bees and butterflies, try spraying aphids off with a jet of water.
Originally published on March 3rd, 2013. Updated on April 30th, 2019.