Determine the best time to plant your seeds. Most flowers can be planted outside any time after the last frost, but some should be planted later in the season. Most seed packets have directions for when to plant, or you can check the planting schedule in the resource section. If you want to start your flowers early, you can plant them indoors six to eight weeks before outdoor planting.
If you're planting your seeds outside skip to step three. If you choose to start your plants inside, fill the pots about three-quarters full with potting soil. You can use small starter pots or seedling trays and eventually transfer the seedlings from the container to the ground, or you can use peat pots, which go directly into the ground and dissolve in the soil.
Plant two or three seeds per pot. Press the seeds about half an inch below the surface, and cover them with soil. If you are planting large flowers, remove extra seedlings so there is only one flower growing in each pot, but planting extras will ensure that at least one seedling germinates. If you are planting directly in the ground, follow the same procedure, but space seeds in rows 2to 6 inches apart, depending on the size of the flowers.
Water the soil until it is damp but not soaking. If you're planting outside you're finished, just water the ground as needed until seedlings appear. If you're using pots, make sure they have holes in the bottom for excess water to drain. Put the pots on a tray or cookie sheet to catch the drainage, and cover with plastic wrap to help retain moisture. Place covered containers in a warm spot away from direct sunlight.
As soon as the seedlings appear, remove the plastic wrap and move the pots to a sunny area or place them under a grow light. Water seedlings as needed until it's time to plant them in the garden. If you're using plastic or metal pots, hold the base of the seedling and tip the pot upside down to remove each flower from its pot. The roots should come out intact, and the whole clump should be planted slightly below ground level and covered with soil. If you're using peat pots, plant the entire pot below the ground, and cover it with soil.