For most gardeners, perennial flowers are the backbone of the flower bed, blooming year after year and providing contrast to annual flowers that will be planted to add extra color every summer. Although a flower bed isn't complete without a variety of summer perennial plants, perennials can be prohibitively expensive if you're on a limited budget. To stretch your gardening dollar and to get a head start on the summer growing season, try your hand at starting perennial seeds indoors.
Read the seed packet to determine when your summer-blooming perennial seeds should be started. Although timing will vary, most perennial seeds will require between four and 12 weeks before they're ready to plant outdoors.
Gather several small containers, at least 2 inches deep. Purchase peat pots or small containers from a garden center or recycle containers such as yogurt or margarine containers. Be sure the containers are clean and that they have a drainage hole in the bottom. If the containers don't have drainage holes, poke two or three small holes with a nail or the tip of a sharp knife.
Fill the containers with regular commercial potting soil, allowing about 1/2 inch at the top of the container for watering. Moisten the potting soil lightly with a plant mister.
Sprinkle a few seeds on the top of the soil in each container. Use your thumb to press the seeds gently into the soil. Mist the top of the soil lightly so the seeds make good contact with the soil. Most summer-blooming perennial seeds won't need to be covered with soil, but read the seed packet to be sure.
Place the containers on a tray or an old baking sheet. Place a plastic bag over the top of each container and secure the bag with a rubber band. The plastic bag will keep the environment warm and humid and will eliminate the need to water the containers.
Locate the tray where the temperature is maintained at 65 to 70 degrees. If possible, place the tray on top of a refrigerator where the heat from the appliance will keep the seeds warm.
Remove the plastic and thin the summer-blooming perennial seedlings when each seedling has a set of true leaves. True leaves are the regular plant leaves that develop after the initial, tiny seedling leaves. Thin the seedlings by pinching off the smallest seedlings with your fingernails. Leave one sturdy seedling in each container.
Place the summer-blooming perennial seedlings in bright, indirect sunlight. Water whenever the top of the soil feels slightly dry to the touch, but don't allow the soil to dry out completely. Water lightly, as the soil should be damp but never soggy.
Give the summer-blooming perennial seedlings a chance to become acclimated to the outdoor environment before planting the seedlings outdoors. Place the seedlings outdoors for two to three hours the first two days. Add two hours to the outdoor time each day. When the seedlings have been outside for at least eight hours, they are ready to be planted outdoors.