The majority of perennial flowers seem to reach their peak in June and July in the Pacific Northwest. With some careful planning you can have just as much color in the late summer garden. Late-season flowers begin blooming in August and continue clear up until the first frost. Plant them along the back of the border or mix them in among the earlier flowers.
One of the toughest and most colorful late-season flowers is the coneflower. The species (Echinacea purpurea) has a purple flower and an orange cone. It is a magnet for beneficial insects. It is not uncommon to see swallowtail butterflies visiting this flower. New colors have been developed to fit any garden design. They can be found in white, pink, purple, yellow, gold, orange and red.The red variety is called "Tomato Soup" and is even a deeper color. The plants vary in height from 1 to 4 feet tall. Coneflowers have sturdy stems and can lend support to the floppier flowers. Plant coneflowers in full sun.
Cape fuchsia (Phygelius) is a valuable late-summer flower. These are not true fuchsias; they are a woody perennial that can develop into a sizable clump. The stems can be cut way back if necessary. They need good sun exposure to bloom, but other than that are easy to grow. Hummingbirds flock to the spikes of the tubular flowers. The leaves grow along the tall stems and provide greenery well before the blooms form. They are available in shades of red, salmon, pink, yellow, white and cream. A popular red variety, "Devils Tears," also has a yellow throat. There are dwarf varieties reaching only 1 foot, and taller forms reaching up to 5 feet. These taller varieties are more like sub-shrubs and need a good amount of space.
Japanese anemone (Anemone hybrida) develops an attractive clump of grape-like leaves early in the season. The deep green leaves create a nice backdrop for earlier flowers. The leaves look nice in flower arrangements. In late summer this plant develops tall stems with clusters of flowers. A favorite single white variety is "Honerine Jobert." There are other forms with pink flowers and those with double white and pink blooms. This plant readily forms little plant-lets, so it requires yearly maintenance to keep it in check. Japanese anemone will look best given regular waterings in the summer.
Every late-summer garden should have at least one clump of red bee balm (Monarda didyma). The vivid, spiky red flowers can also be used in salads and teas. It is the first plant in your garden hummingbirds will visit. As they age the leaves can be prone to mildew. The best way to avoid this is to plant the most mildew resistant variety, "Jacob Cline." Bee balm can also be found in pink, lavender and white varieties. Plant these flowers in full sun or partial shade and give them average moisture. They will also tolerate soggy situations.
The cobalt blue flowers of anise sage (Salvia guaranitica, "Black and Blue") are stunning. Place this tall plant at the back of the border. When the other flowers begin winding down, this one will be covered in flowers. It earns its name from the black calyxs that hold the deep blue flower petals. This is a perennial flower but needs a protected spot in case the weather turns bad. Place it next to a building where it will get cover. It will do fine if it receives partial sun each day.