Sunflowers are popular additions in many home gardens and growing them can be especially rewarding. In fact, sunflowers are one of the easiest flowers that you can grow in the garden.An annual plant, sunflowers have big, daisy-like flower faces of bright yellow petals and brown centers that ripen into heavy heads filled with seeds. Tall and coarse, the plants have creeping or tuberous roots and large, bristly leaves. Some sunflowers grow to over 16 feet in height, though there are also varieties today that have been developed for small spaces and containers.