One of the perennial powerhouses of the plant world, catmint is extremely versatile and easy to grow. Rich purple blooms explode into color in early summer for a spectacular show that can last quite a while. These plants can also handle a variety of tricky soil situations, so as long as you have sun, you can probably grow catmint.
Because catmint tends to come in soft colors, generally blue/purple blooms on top of cool grey-green, this plant is easy to pair with other perennials and annuals without clashing. The bloom show tends to reach its peak color just as most of the spring bulbs are finishing and before many of your summer perennials begin to bloom, easily filling in some color during that green season. They are also a wonderful source of nectar for many pollinators.
Blooms of colorful catmint can also hold on for quite some time. Much like its closely related salvias, plants can also be sheared back after the initial wave of blooms in order to encourage a second round of color. This also helps to keep the plants looking tidy and not becoming too overgrown.
Catmint Care Must-Knows
Catmints are fast-growing plants. When they first begin in spring, they form tidy little mounds of neat new foliage. This quickly grows outward as plants begin to set their buds for their flower show. One of the most common varieties grown is called 'Walker's Low.' However, don't be fooled by the name—this is by no means a low plant. These plants quickly reach their full height of around 3 feet tall by 3 feet wide. Once their flowering spectacle is complete, many of the catmints become leggy and flop open. If this is the case, you can easily remedy that by giving the plants a good cutback. This will encourage a nice new flush of growth, as well as a second round of flowers if you are lucky.
One of the best things about catmints is their toughness and ability to handle poor soil conditions. If you've had problems in the past growing things in heavy dry clay, look no further! Catmint can handle it and still thrive. An important thing to keep in mind, however, is that these plants do like sunshine. They can handle part shade, but they will be much more likely to flop open. It is also important to note that many species of catmint can become weedy in the garden setting. If you are worried about this, look for sterile varieties like 'Walker's Low' that will not seed about and cause any future problems. Catmint is also known to withstand harsh winters.
Catmint or Catnip?
The plant commonly planted in most garden settings is not your typical catnip that you would give to your cats to induce momentary craziness. The common catnip is actually a close relative called Nepeta cataria. This catnip produces a compound called nepetalactone, which triggers the response in cats that we all know and love. Many other species of nepeta also produce this compound but in much smaller doses.
More Varieties of Catmint
Nepeta x racemosa 'Blue Wonder' is compact at 12-15 inches tall. Its neat wrinkled leaves are grayish-green and show off the 6-inch terminal spikes of two-lipped dark blue flowers. Zones 5-9
Nepeta cataria, otherwise known as the common catnip, is a herbaceous perennial that makes cats crazy. Zones 3-7
Nepeta racemosa 'Little Titch' is a lovely dwarf plant forming a compact mound of green foliage with blue flowers. It grows just 8-10 inches tall and spreads up to 12 inches wide, making a great border or edging plant. It blooms almost constantly from late spring through fall. Zones 4-8
Nepeta × faassenii is a tough perennial herb that thrives in hot, dry weather. Plants feature mounding sprays of silvery-green foliage with a flush of blue flowers. Deadhead or cut back after the first flush of bloom to encourage more flowers. It grows 1-2 feet tall and spreads up to 2 feet wide. Zones 4-9
Nepeta × subsessilis bears the largest flower clusters of any catmint. Bloom spikes may be 8 inches long and 3 inches wide on plants that grow up to 4 feet tall. Sturdy stems keep the plant from requiring staking or shearing to maintain their strong upright habit. Like other catmints, it has a long season of bloom. Zones 4-8
Nepeta mussinii is a low-growing species that remains under a foot tall with a spread up to 18 inches wide. It's the first catmint to begin blooming in spring, and although it slows down in the heat of summer, it blooms almost constantly until hard freezes arrive in fall. This species self-seeds readily in the garden and can become weedy if it's not deadheaded regularly. Persian catmint is especially cold-hardy. Zones 3-9
Nepeta 'Six Hills Giant' is sometimes incorrectly listed as a variety of Nepeta × faassenii. It closely resembles that species in all qualities except size—it's twice as large, growing to 3 feet tall and 30 inches wide. It can flop open in midsummer, but if you cut it back after the first flush of bloom, it will reliably rebloom and maintain a uniform mounded habit. Zones 4-9
Catmint Companion Plants
Perhaps the best-loved perennial, herbaceous peonies belong in almost every garden. Their sumptuous flowers—single, semidouble, anemone centered (or Japanese), and fully double—in glorious shades of pinks and reds as well as white and yellow announce that spring has truly arrived. The handsome fingered foliage is usually dark green and remains good-looking all season long. Provide it with deep, rich soil with plenty of humus to avoid dryness, and don't plant the crowns more than 2 inches beneath the surface. But these are hardly fussy plants. Where well-suited to the climate, they can thrive on zero care.
These vigorous growers are beautiful additions to the garden. They vary from tall, stately plants suitable for borders to others that can be planted as creeping groundcovers. Flowers, too, vary from tight spikes of 1/2-inch to 1-inch cups carried alone or in whorls. Humus-rich, moisture-retentive soil is recommended; some varieties enjoy wet soil and ample water. Several sorts may become invasive and need to be corralled. Note: These are not the invasive purple loosestrife, which has been banned in many parts of the United States.
Bee balm is a wonderful plant for attracting butterflies and helpful bees. This prairie native has spiky flowers in jewel tones of red, pink, purple, and white, surrounded by dark bracts. They grow atop substantial clumps of dark foliage. The aromatic foliage is sometimes used for making tea, and bee balm is often grown in herb gardens. Established plants tend to spread, especially in damp soil. This plant is extremely prone to mildew problems, so be sure to plant in full sun and seek out cultivars touted as resistant to mildew diseases.