Annual flowers produce an abundance of color in the garden. Certain annuals in the southern half of the U.S., such as pansies and snapdragons, can survive a hard frost or a light dusting of snow. However, most annual flowers are grown to provide fast color in the landscape during the spring and summer. For example, the zinnia can go from seed to flower in as little as 45 days from planting. Most annual flowers need little care outside of regular watering, but for the best performance, plant all annual seeds at the correct depth with the right spacing between plants.
Plant your annual seeds at the correct time. For example, larkspur seeds and cornflower seeds are planted in the fall so they receive cooler temperatures over the winter needed to germinate, or sprout. Zinnia and marigold seeds germinate when the soil warms in the spring. If you plant at the wrong time, the seed may not sprout, or the plants may be stunted.
Plant in an area that receives full sun--six hours of direct sun each day. Some annuals bloom in the shade, but most put on the best show if planted in full sun. Read the planting instructions on the package or catalog to verify the right planting location for your seed.
Clear the area of all weeds and pulverize the soil to a depth of 6 inches, using a rake and hoe. Cover the area where you are planting your seeds with a 1-inch layer of compost and the amount of granulated organic fertilizer recommended on the fertilizer container label. Work the compost and the fertilizer into the top 2 or 3 inches of soil with a rake or hoe. Rake the area smooth.
Plant your seeds at the required depth, based on the instructions on the seed package. Some annual flower seeds, such as snapdragons, need light to germinate so they must be set on top of damp soil; other seeds, such as zinnias, are covered with soil to 1/4 inch deep.
Mist the soil lightly with a spray bottle and keep the soil moist, but not wet, until the seeds germinate. Continue to keep the soil moist until the plants are actively growing, then water deeply every three or four days if there is no rain and the temperatures are warm. Do not allow the plants to wilt, or the number of blooms produced may decrease.
Spread a 1- or 2-inch layer of mulch over the root bases to conserve moisture and control weeds. Don't apply mulch over small plants or newly planted seed as this may kill young seedlings or prevent seed germination.