Sunflowers provide bright color to your garden throughout summer. Once they begin to fade, they produce a bounty of edible seeds. If you have no need for the seeds, leave them out to provide feed to over-wintering birds. The birds add life to the quiet winter landscape and are interesting to watch as they search for food. Growing sunflowers for birdseed is not much different than growing them as an ornamental. The main difference in care occurs once the flower fade.
Choose a well-drained garden bed in full sun for the sunflowers. Lay a 2-inch layer of compost over the bed and till it in to a 10-inch depth to add further drainage and provide nutrients for the plants.
Sow small seeds ½ inch deep and larger seeds 1 inch deep. Space dwarf sunflowers 1 foot apart and giant varieties 2 feet apart in the bed.
Water the soil until it is evenly moist. Water daily to maintain soil moisture until the seeds germinate, approximately five to 10 days after sowing.
Water seedlings enough to provide 1 inch of water a week to each plant. Apply a 1-inch layer of mulch around each plant to help retain soil moisture.
Allow the flowers to fade naturally on the stem. Cut them off once the green back of the flower begins to turn yellow.
Place the flower heads in a warm, dry place until the back turns dark brown. Brush your hand over the seeds in the center to knock them off.
Use the seeds in bird feeders or leave them on the flower head and set the whole head outside for the birds. If desired, let the heads go to seed on the plant and cut down then entire sunflower in spring once birds have pecked out all the seeds.