After years of experimentation, here are a few perennials that actually bloom for months. While not as spectacular as some short-lived varieties, such as poppy, these are worthy additions to any garden. At this time of year, perennials generally go on sale and are great bargains.
Walker's Low Catmint (Nepeta) is a favorite. It does the best in full sun, but can tolerate a little shade. Too much shade and it gets leggy. It grows to about 18" tall and stays in a compact 2 ½' clump. Blue/purple flowers are noticeable from June to October, although it flowers most abundantly in July. Walker's Low Catmint has withstood some hard winters with no dieback.
Agastache foeniculum grows best in full sun. It reaches 2 ½' tall and carries 3" spires on the top of the plant. The purple flowers smell like licorice when broken and can be used for seasoning or tea. This perennial tends to reseed in other spots in the garden; however, it is not aggressively invasive. Although Agastache foeniculum is rated Zone 6, it has survived some hard winters without problems.
Japanese Aster ( Kalimeris pinnatitida "Hortensis") grows 2-3' tall in a full cluster. Small 1" daisy-like white flowers with yellow centers are borne on the top of the plant for about 3 months. The bountiful, delicate flowers can cover most of the foliage. This perennial does the best in full sun.
Blue Chips Bellflower (Campanula carpatica "Blue Chips") often blooms from June to September. Full sun gives best results for this 8" tall plant. Medium blue, flat flowers are supported on thin stems with the foliage hugging the ground.
Black-eyed Susan (Rudbeckia fulgida "Goldstrum") is one of the most cheerful, dependable perennials. It grows to 2' tall in full sun and keeps a tight, upright shape. Deep yellow daisy-like flowers have a black coned enter. "Goldstrum" normally blooms from July to September. It is very hardy.
Bleeding Heart (Dicentra tomosa "Luxuriant") does well in
shade to about 3 hours of sun. Luxuriant Bleeding Heart has fern-like
foliage. The small pink flowers last all summer, although rarely abundant,
and stand out against the delicate leaves. It reaches up to 18"
tall and remains in a dense 2' clump. Winters have not diminished its
Garden Pinks (Dicentra) are compact small plants that need to be at the forefront of the bed. "Frosty Fire" is one of the best Pinks with its silver foliage topped with fire red flowers. This variety gets 6" tall and perhaps a foot wide. Deadheading is needed to keep "Frosty Fire" full and healthy. This plant does well in full sun and would be a good choice for a small garden.
Speedwell (Veronica) grows 9-18" tall in compact clumps in full sun. The white varieties have seemed to flower more prolifically than pink and dark blue, yet all are very nice plants. The spikes can be 3" long and narrow. Noah Wiliams (Veronica spicata "Noah Williams") is a better white form. Speedwell has proven to be very winter hardy.
Lipstick Strawberry (Fragaria "Lipstick") is an ornamental that rarely produces fruit. It can be used in hanging baskets or as a groundcover. It grows in sun or partial shade and becomes full if the long runners are pinched back. Pink flowers last all summer. The occasional fruit is small and sweet. Mulching is not necessary, as with commercial strawberries.
Yarrow (Achillea) is a great addition to any garden. The leaves have a unique appeal and the available colors are many. Yarrow can be used for cut flowers and are good for attracting butterflies. In full sun, Yarrow can reach 2'. This species has proven very winter hardy.
For best bloom results, or reblooming, cut dead flowers as soon as
they dry. Watering in early morning during dry periods is also helpful,
but not mandatory for most of the above. If you do not have much space
in your garden, the above plants will give you the maximum bloom time.
© Shaker Hill Nursery