Annuals accent the garden with color all summer

There’s no denying annuals’ important role in the garden.

They’re easy to grow, come into bloom quickly, flower a long time and are inexpensive to replace every year. They’re among the most forgiving and adaptable of plants, needing just good light, ample water and some reasonably fertile soi

True annuals complete their life cycle — growing from seed, flowering, setting seed and dying — in a single year. But many plants sold as annuals are really tender perennials that won’t make it through the winter in colder areas. The plants I’m highlighting here come from both categories, but we’ll think of them as annuals for the sake of convenience.

Marigolds: Full sun; drought-tolerant, but prefers moist soil; 6 inches to 3 feet tall and wide, single and double flowers 1 to 3 inches across; nonstop color in reds, oranges, yellows. If drought-stressed, may develop spider mites. Just hose them off and keep well watered. They’re a favorite companion plant of mine in the vegetable garden.

Snapdragons: Full sun to part shade; 6 to 36 inches tall, 8 to 12 inches wide; red, yellow, peach, pink, orange, burgundy, white, bicolor; single and double flowers. Rust may be a problem in hot weather.

Lantana: Thrives in the heat and full sun; 1 to 6 feet tall, 2 to 8 feet wide; white, yellow, pink, orange, red; many have multiple colors, with younger and more mature flowers in the same cluster. A tender perennial, it can overwinter in a container; where hardy, it’s a woody shrub; grown as an annual in a cooler area, it won’t get as large. These are real butterfly magnets, and no serious pests or diseases.

Impatiens: Part shade; moist soil; 6 to 8 inches tall and wide. Possibly the most popular annual in the world; plant among hostas for summer color or grow in containers. Slow to start in cool spring, plant a little later than other annuals; protect from late frosts. May be prone to slugs. Impatiens are one of the best choices for adding color to a shade garden.

Petunias: Full sun to part shade; moist, rich soil; 6 to 18 inches tall; 1 to 5 feet wide; loved for their bright colors and spreading habit; white, pink, red, purple, blue; may have striped petals or contrasting veins; large or small flowers; double or single form; low-growing mounders are great in containers, spreaders like Wave varieties spill over walls or cover a lot of ground. Deadhead and pinch back foliage if they get straggly. You may encounter occasional aphids and slugs.

Annuals are terrific as splashes of accent color. Because they bloom all summer, they can fill in for perennials or mixed borders after their late-spring wave of color has passed, and in midsummer when the rest of the perennials aren’t blooming. For bigger impact, plant in groups of three or five in garden soil that’s well drained.

Mulch the area around the plants to keep soil moist. Their constant display of color makes them heavy feeders. Once established, use a balanced organic fertilizer to encourage blooms.

Annuals need about an inch of water a week. Water deeply in the morning to encourage deep roots, and keep foliage dry during watering to prevent disease.

Joe Lamp’l, host of “Growing a Greener World” on PBS, is a naster gardener and author.