What follows are a few pearls of wisdom concerning garden beds for annuals. Because annuals have a relatively short time to grow and perform in the landscape, good bed preparation is essential for a good blooming show.Beds should be deeply spaded, to a depth of three to four centimetres if possible. Most annuals grow well in a variety of soil types, as long as said soil is capable of holding a sufficient amount of water while offering good drainage as well. Heavy soils should be amended with sand, perlite or coarse bark to improve drainage.
To test for drainage, dig a hole about 25 centimetres deep and fill it with water. The next day fill the hole again and see how long the water remains in it. Should it drains away in eight to 10 hours or less, drainage is satisfactory for most annuals. Most of the annuals you see in commercial landscapes are in raised beds to insure adequate drainage.
Many annuals can be directly sown in their final locations. Small seeds, however, present more difficulties. Carefully prepare the bed and pay close attention during germination and initial growth of the seedlings. Thinning is often required, and do this before plantlets are in danger of crowding each other out.
The recommended seeding date, depth, and spacing are usually included with other information on the seed packet.