More Flower Power IS Possible

July 28, 2025 | C.L. Fornari | Annuals

Adding annuals to your perennial garden in early August

Many people find that while their perennial and garden beds are filled with colorful blooms early in the summer, they have more foliage than flowers by the end of July. Most gardeners, however, can add a few pots of annuals at the beginning of August and have flower power for three more months. Here are some plants that will add color to your flowerbeds, and some tips for getting them quickly established.

The daylilies and the June flowering perennials in this garden are finished, but the Profusion Zinnias and Ageratum add flower power into November in this Cape Cod garden.

If a perennial isn’t an asset in the garden right now, cut it down to the ground.

Catmint (Nepeta), perennial blue Salvia, bee balm (Monarda), Geranium ‘Rozanne’ and some other perennials can look tired, leggy or browned at this time of the summer. These plants can be cut down to between 2 and 4 inches tall. Even daylilies that have finished blooming can be sheared to remove old stems and brown or yellow leaves. Many of these perennials will respond with new leaf growth this summer and look fresh again. Geranium ‘Rozanne’ will even make new flowers and continue to bloom into the fall. In addition to getting the less-than-attractive foliage out of the garden, this also opens up spaces where you can plant a few pots of annuals.

Profusion Zinnias are a favorite annual to place in perennial gardens because they don’t need to be deadheaded, attract pollinators and butterflies, and come in several cheerful colors.

Scatter time-release synthetic fertilizer in the area before planting.

After cutting finished perennials back, dig holes where you want annuals to go and scatter some Shake n’ Feed or Osmocote time-release fertilizer in the hole and around the area where the plant will go. A tablespoon or two per pot is perfect. While we usually recommend organic fertilizers for lawns, landscapes and gardens, annuals benefit from “fast food.”

Annual Salvia is often the plant of choice for placing where the earlier flowering perennial salvia was growing. These plants have attractive blue flowers but unlike the perennials, they continue to bloom in late summer and into the fall until hard frost.

Design tip: Plant Annuals in Groups of 3

Just as perennials look best planted in groups of 3, 5 or 7 plants, annuals are also better able to strut their stuff when they have company. When it comes to flower power, more is more.

Marigolds provide the pop of orange that is invigorating in sunny gardens. They also attract butterflies, so you gain color and motion.

Water plants in well after placing them in the garden.

Remember that pots of newly planted annuals have a root system the size of the pot they were in, and these will dry out more quickly than established plants. You may need to supplement the watering around new annuals for three or four weeks while their roots grow into the soil.

For hot locations near a stone walkway or driveway, Catharanthus is the annual of choice. These are also called flowering vinca, and they are very heat tolerant.

Use annuals appropriate for the amount of sun or shade available.

Before choosing your annuals, watch to see if the area where you’ll be planting is currently in the sun all day, in the morning only, or in the afternoon. Gardens that only receive morning sun or dappled sunlight through trees should be planted with shade tolerant annuals such as begonias, impatiens, or coleus.

The Beacon hybrid Impatiens are not only known for flower power, but for their resistance to Impatiens Downy Mildew. This is especially valued as summer goes into fall, since IDM is more active in cooler, damp weather. These Impatiens are perfect for part-shade or morning sun gardens, pots or boxes.

Begonias are a free-flowering, shade loving plant for places with less sunlight. There are many varieties of begonias available, including the pink, white or red flowering wax begonias.

Posted in Annuals