Plants and flowers that are grown from seed can make it easy to enjoy several new plants from one old plant. There is some ability to plant many different seeds in the same garden, from early bloomers to late season bloomers. If you are looking to start a garden with seed flowers and plants, there are some good candidates like calendula, yarrow, spider flower and Mexican sunflower.
Calendula, or Calendula officinalis, is from the Asteraceae/Compositae, or Aster/Daisy family. It is an annual, fast growing and great for the beginning gardener. Calendula can grow 12 to 30 inches in height and in width, with flowers getting two to three inches across. The flowers can be single or double, and be in the hue range of white, yellow and orange. Calendula prefers sun or partial shade, with average moisture, and can be propagated by seed after the last frost. It has been a medicinal plant for ages, being used for skin irritations and muscle sprains.
Yarrow, or Achillea millefolium, is from the Asteraceae/Compositae, or Aster/Daisy, family. It is a perennial that attracts butterflies and has over 100 different species. There is delicate foliage and a flower head that has daisy like flowers. It will get one to three feet tall and the flowerheads are two to three inches across. Yarrow requires full sun and a well-drained soil. It is propagated in the spring and autumn by division or by seed. Seed will give a greater chance at varied color.
Spider Flower, or Cleome hassleriana, is from the Capparaceae, or Caper, family. It is an annual that will get to five feet high with one- to two -inch flowers. Cleome hassleriana prefers full sun but tolerates some shade and needs a fertile, well-drained soil. Start seeds inside to propagate, planting after the last frost one foot apart from each other. These are extremely easy to grow and they aren't affected by pests.
Mexican sunflower, or Tithonia rotundiflora, is from the Asteraceae/Compositae, Aster/Daisy, family. It is an annual that attracts butterflies and a fast grower. Tithonia rotundiflora will get five to six feet tall with four- to 10-inch leaves. Its flowers are red and orange and three inches across. It prefers full sun but tolerates partial shade. Plant in well drained soil and propagate via seed.