What Is an Annual?
Annuals are the summer romance of plants. Unlike the biennial, who lives for two years and then exits like a well-mannered houseguest, or a perennial, who demands a longer-term commitment, annuals sweep in and woo you with their bright, pollinator-attracting petals. They fill your garden with hummingbirds, honeybees, and (yes!) flowers. And then, just as their generous beauty has left you smitten, lying amongst their spent petals and marveling at the swift passage of time, they steal away, leaving behind fond memories (and, perhaps, a few seeds).
Annuals are typically easy to grow and maintain. All they need is a regular drink of water and regular deadheading. Here are a few tips for growing your annuals:
Deadheading
The mission of an annual is to produce seeds so that the propagation of future generations is ensured. But to maximize your blooms you want to keep the plant from setting seed, because once it starts making seeds it stops making blooms. So your job is to deadhead regularly, meaning pick lots of bouquets (it feels like you're robbing the plants but really you're helping them make more flowers) and if you miss some blooms and they get faded, clip off the faded blooms.
When to plant
Generally speaking, all annuals can be planted after your last frost, easy peasy. Annuals can be divided into hardy (e.g. Nigella), half-hardy (e.g. Cosmos), and warm season (e.g. Marigolds). Hardy annuals can be planted in fall or early spring and can withstand a little frost. They will sometimes even come back to bloom the following year. Half-hardy and warm season annuals are planted after the last frost, the difference being that half-hardy annuals will survive a couple of light frosts better than the warm-season annuals, which often won’t begin to flower until the height of summer when the nights stay warm.
Care
To encourage blooms, many gardeners fertilize their annuals when they plant them and again midsummer.
Pinch your plant by cutting back the center stem when the plant is about 9-12" tall to encourage the plants to be more full and lush. Similarly, you can cut back your annuals when they get tall or leggy. It will take a few weeks for them to recover, but they will grow back lusher than ever.
Once your plants are established, water only when the soil feels dry; letting it stay soggy can cause root rot.
Water early in the day so the plant’s foliage can dry off as the day warms up.
Color
Annuals will help keep your garden in bloom all season long. They allow you to have a fresh, new visual experience every year.
Mix it up! Annuals are like peel-and-stick wallpaper, low commitment, flashy and fun. Try something new, these plants are you chance to go bold and experiment.
The flowers on your annual plants will naturally slow down in late summer to early fall. Replace them with fall plants until you can start a garden of fresh annuals next spring.