These annuals are easiest in perennial borders
Even perennial purists can't deny that annuals are color powerhouses. Planted in the border, they provide playful pops of color when perennials are on a blooming break.
However, keeping the garden in color all summer with annuals has one drawback. Deadheading annuals woven through perennials can be tricky, requiring acrobatic moves to maneuver through the plants.
The solution is simple. Plant annuals that deadhead themselves, or self-clean. There are lots of choices — some for sun; some for shade.
Angelonia is commonly called summer snapdragon for two reasons. First, their spires of flowers, in shades of blue, purple, pink, white and bicolors, resemble small snapdragons. Secondly, they bloom and bloom all summer long. Most varieties grow upright and range in size from 12 to 24 inches tall.
Plant Angelonia in full sun for best flowering after all danger of frost has passed. They love warm, well-drained soil and summer's heat. Pinch the tip of the main stem of young plants before planting to encourage them to branch. Don't overfertilize summer snapdragons. A light feeding with a fertilizer for blooming plants once a month is plenty.
Begonias are easy to grow and bloom from late spring to fall in shade to nearly full sun. Plant them in well-drained soil and feed them once a month.
Wax begonias are ideal to edge a border. The Harmony series features bronze foliage. The Prelude series displays green leaves. Both bloom in white, salmon-pink and red.
Dragon Wing, Whopper types and the Big series grow larger. They are tough plants that bloom without fail. Dragon Wing begonias grow up to 18 inches tall and wide. Whoppers grow even larger. The Big series is noted for its earlier bloom and larger flowers. Choose a favorite variety for the shade garden in combination with hostas and ferns.
Million bells, botanically named Calibrachoa, is about as perfect as an annual can get. It blooms like crazy from spring until frost. Its flowers resemble mini petunias and are available in single and double-flowered forms, bicolor and tricolor varieties, and striped types in just about any color in the rainbow.
Some are mounding; others ramble about the garden. They are not fussy about soil but prefer slightly moist conditions. Plant them in full sun or light shade. Add slow-release fertilizer to the soil when planting and a monthly feed will keep them happy.
If plants ever begin to look unkempt, cut them back by half. New growth will quickly begin, and they will start flowering again in a couple weeks.
Until downy mildew swept across our area, impatiens were the annuals for color in the shade. Now, a resistant cultivar has been developed by Syngenta that has been tested in trial gardens across the county and given rave reviews. The Imara XDR series grows about 12 inches tall and wide and is available in six colors: orange, orange with a white star in the center, red, rose and violet.
Wait until the soil has warmed and there is no longer danger of frost before planting impatiens in well-drained, compost-amended soil. Mix in a slow-release fertilizer when planting and feed every two to three weeks with a fertilizer formulated for blooming plants. Water them if there is not enough rainfall to keep them slightly moist.
I can't think of a reason every gardener with a sunny garden doesn't plant flowering vinca. It is a profuse bloomer, easy to grow, loves the heat and needs little care as long as it is planted in well-drained soil in a spot with good air circulation.
Flowering vinca (Catharanthus roseus) grows about a foot tall and blooms in pink, purple, magenta, red, white and bicolors over glossy green foliage. They are very drought tolerant and resent overwatering. In fertile garden soil, they will not require fertilizing. If needed, fertilize once each month with an all-purpose fertilizer according to the directions on the package.
Plant some of these annuals that don't require deadheading in perennial borders. You will keep them bursting with color and still have time to sit back and enjoy summer.
• Diana Stoll is a horticulturist, garden writer and speaker. She blogs at gardenwithdiana.com.