Any group of plants that combines a cheerful, floriferous disposition with ease of culture should be hugely popular. But somehow annuals are still associated with those vast, formal bedding schemes, so popular with our Victorian forebears and whose dying embers linger on in the truncated tradition of "bedding out" in public parks. Unsurprisingly this has prejudiced the discerning gardener against them but a quick browse through the catalogue reveals that this is not the full story.
My inclination is to keep it simple and utilise the tough nuts, the hardy annuals which I think represent the more delicate, subtle and attractive side of the annual round. These don't require mollycoddling and can be sown "in situ", literally where they are to flower.
Hardy annuals are the most obliging of plants but there are certain minimum requirements if they are going to perform for you. Firstly, an open sunny position is essential. Secondly, a reasonably good, well-drained soil as starvation and drowning are serious health hazards for anything. Lastly, sufficient space for each individual plant to develop as overcrowding will stunt growth. A common misconception is that hardy annuals thrive on neglect but digging in well-rotted manure, composting every other year and always giving a base dressing of a balanced fertiliser when preparing the seedbed, will ensure a no-starvation diet. Timing of sowing is dependent on weather and local conditions. The soil needs to be workable and above 7C (45F). With outdoor sowings, patience and picking the right moment are definitely a virtue. Mid-April is plenty early enough and you still have time now to sow if you are prompt!
Having prepared your seedbed and firmed it you can then transfer your plan, which should show the position of each cultivar and be worked out on paper beforehand, onto the beautifully raked ground by drawing the pattern in the soil with a finger or stick. Seed of each cultivar is then sown in the appropriate position. You can broadcast it but I prefer to sow in shallow drills, that is, in straight lines equidistantly spaced at 7.5-15cm. This makes it easier to distinguish between weed and flower seedling and also facilitates thinning later. This thinning is essential to produce sturdy, well developed plants and should be undertaken as soon as the seedlings are big enough to handle. Choose a moist, mild day, select and retain the sturdiest specimens and as you go re-firm the soil with your fingers to ensure close contact between soil and seedling.
Once established annuals generally require little maintenance; partly a reflection of their short but sweet lives. However, until they close their canopy pay careful attention to weeding. Once they have done so the weeding should drop right off, hooray! Watering is important during germination and until the seedlings begin to mature but thereafter should only be an issue in drought periods. If growth is really poor a liquid feed is a good way of providing a quick pick-me-up. Taller, floppier varieties such as Clarkia or Godetia benefit from a little discrete underpinning with brushy sticks. And that's about it, just sit back, light the blue touch paper and wait for the floral fireworks.