Although I love growing vegetables, perennials are also among my favorite plants to cultivate. They return year after year, often growing bigger and blooming better with each passing season. Because I don’t have to purchase new plants each year, I save money by gardening with perennials, and I love sharing divisions of my favorite plants with friends. Plus, these stalwart plants don’t require a lot of attention from you. I mulch my perennial beds every spring to cut down on weeding and watering, and I deadhead/cut back the plants two or three times during the growing season; other than that, I don’t do much in terms of maintenance.
That being said, there’s one major downside to growing perennials: Many of them have relatively short bloom times. Some are only in flower for two or three weeks. To keep my garden in constant color, I include a lot of perennials with interesting and colorful foliage, and I try my best to include a mixture of plants with varied bloom times to ensure something is always in flower, but there are only a handful of perennials with very long bloom times. In fact, if they’re deadheaded from time to time, these beauties are in flower almost all summer long.
Here are some of my favorite long-blooming perennials that will bring a burst of color to your landscape for weeks on end. All are hardy down to USDA hardiness zone 5.
Yellow Bleeding Heart (Corydalis lutea)
I’ve written about this shining little star (pictured above) before, touting its non-stop flowering and cold tolerance. The blue-gray, ferny foliage forms soft mounds in shady areas. From April through frost the plants are covered with clusters of delicate yellow flowers. My plants have even been spotted blooming on Christmas during mild winters in my zone 6 garden! This is a great addition to shady borders and woodland gardens, and it self-sows throughout the garden but not in an aggressive way.
May Knight Salvia (Salvia nemorosa ‘May Knight’)
This perennial salvia is a personal favorite for the spikes of deep-blue flowers it produces all summer long. The bees and butterflies love it, too. The trick to keeping this plant in bloom is to snip off all the spent flowers every three or four weeks throughout the summer. Then, in July, I cut the entire plant back to the cluster of leaves at the base of the plant. This stimulates even more flowering. May Knight isn’t the only perennial salvia with a long bloom time either. Try Caradonna, East Friesland and Blue Hill, as well.
Russian Sage (Perovskia atriplicifolia)
If you’re looking for a drought-tolerant, pollinator-friendly plant that blooms from June through frost, Russian sage will fit the bill. The skeletal structure of this plant makes an excellent addition to perennial borders and pollinator gardens. The highly fragrant foliage keeps the deer and rabbits from having a taste, and Russian sage cannot be beat for the lovely blue shade of its flowers. If you find the plant to be too floppy, try the more upright species, Perovskia longin.
Walker’s Low Catmint (Nepeta ‘Walker’s Low’)
Another exceptionally long-blooming perennial, Walker’s Low is my favorite variety of catmint. While catmint is closely related to catnip, it is not the same species of plant. Catnip is best for kitty, while catmint is best for the garden. The spires of billowy, light-blue flowers are adored by pollinating syrphid flies and bees alike. With a few well-timed, aggressive “haircuts,” catmint will stay in flower from late April through fall’s first frost. I cut my plants back to the ground after every flush of blooms—two or three times during the summer or whenever the plants are looking scraggly. The plants are deer and rabbit resistant, too.
Lavender Phenomenal (Lavandula x intermedia Phenomenal)
If you’ve been dreaming about having a lavender that blooms over and over again, Phenomenal is the plant for you! This hardy lavender hit the market in 2012 and has become a darling of lavender growers everywhere. This variety does not exhibit die back in the winter like many other popular varieties do, and it’s very tolerant of heat and humidity. The repeat blooming trait makes Phenomenal truly phenomenal! The mounds of silvery-blue foliage are topped with hundreds of flower wands throughout the summer. Highly fragrant and adored by pollinators, this lavender is a winner in my garden.