Theme gardens are the rage these days. Why not build a perennial bed that satisfies three themes at once? The following five perennials attract butterflies, repel deer and represent the cool end of the color spectrum, in various shades of purple.
The members of this list work well together, with the taller, sun-loving shrubs providing the partial shade preferred by the lower growing, compact plants. All are hardy to Zone 5 and reasonably tolerant of fluctuations in rainfall. In other words, they can thrive across a broad swath of U.S. gardens. In most of the Zone 5-8 range, this assortment of purple plants will guarantee blooms -- and thus butterflies -- from early spring to mid-fall.
Catmint (Nepeta faassenii) is the perfect choice for the edge of this three-theme bed. Catmint is related to catnip (Nepeta cataria) but showier, more fragrant and less addictive to cats. Catmint has the added virtue of being low maintenance. It grows in compact mounds that rarely stray into other plants’ territory, but can hold their own against more invasive companions. The faassenii type rarely exceeds 20 inches in height.
Somewhat taller versions of ornamental catnip are available, as well. They lie at the same end of the color spectrum and similarly serve as a draw for butterflies, while repelling deer.
Of the five plants in this list, catmint will be the first to show signs of life in spring. Before much of anything is in bloom, the bluish-green leaves of catmint provide a welcome splash of color. Although catmint enjoys its most robust flowering in spring, it will continue to bloom through summer, especially with dead-heading.
Like catmint, lavender (Lavandula angustifolia) is ornamental even without a single blossom. In colder climes, lavender shares catmint’s relatively low-growing status and will happily share space at the edge of the garden bed. In warmer climes, lavender grows more robustly and should be planted between the catmint and the taller perennials.
Although lavender is an evergreen in warmer climes, it dies down to the roots in Zone 5. But even there, lavender will send out new shoots before mid-spring.
Lavender beats out catmint for aromatic appeal. The fragrance that attracts butterflies and pleases the human nose turns off deer.
In colder regions, the chasteberry shrub (Vitex agnus castis) would rank in the middle of this list in terms of height. In Zone 5, spring growth will come from beneath the soil or on the very lowest of the previous year’s branches. Some years, the resurrection will not be visible until early June. As a result, the shrub rarely exceeds 4-5 feet in colder climes, but serves as a small tree in the warmest end of the hardiness range.
If chasteberry can be slow to start, it struts its stuff in the hottest days of summer, when many other perennials grow tired. Its bluish-purple flowers may be tiny, but grow in such profusion that, from a distance, the chasteberry shrub looks like a lavender cloud speckled by butterflies. Not surprisingly, chasteberry is also known as wild lavender in its native Mediterranean region.
In terms of fragrance, chasteberry is a worthy competitor for lavender. When bruised, the leaves, flowers and stems of this shrub exude a spicy aroma, somewhat reminiscent of witch hazel. That aroma has the added virtue of serving as a deer repellent.
This shrub is probably better known by its Latin classification than by its common names: bluebeard, blue spirea and blue-mist shrub. There are two main versions, Caryopteris clandonensis (which includes several variants) and Caryopteris divaricata, also called Nepalese caryopteris. Both versions bloom late in the growing season. Both have attractive bluish purple flowers that attract butterflies. Both have odd smelling leaves that are deer resistant.
Of the two main versions, Caryopteris clandonensis is more compact and better suited to the border area. Some versions of clandonensis are not hardy in Zone 5 gardens. Several are.
Nepalese caryopteris, on the other hand, is a rugged shrub that withstands tough winters. Although it dies down to its roots in winter, it grows vigorously and can easily reach 5 or 6 feet in height by the end of the growing season. It can be invasive, but moderate pruning and weeding keep it in bounds. Nepalese caryopteris leaves have more than an odd smell. They smell downright nasty when bruised. Because of that unpleasant aroma, the Nepalese caryopteris ranks among the most deer resistant-shrubs. To butterflies, however, the smell is not remotely offensive. They eagerly sample the nectar in the bluish purple flowers.
Buddleia, better known as the butterfly bush, includes many attractive shrubs. The variant most familiar to gardeners is Buddleia davidii. The butterfly bush is aptly named. At times, it looks like it is actually sprouting butterflies. They flock to its long flower spikes, which start blooming in early summer. With regular dead-heading, the butterfly bush will continue to bloom profusely -- and to attract butterflies -- until the first frost, and even after.
In warmer climes, the previous year’s branches will erupt in new growth in spring, which is why pruning is essential in late winter. In Zone 5, the perennial usually dies to the ground. But that late start does not prevent the butterfly bush from reaching well beyond 6 feet. Some gardeners complain that it is an untidy specimen, but others are enthralled by its long, arching canes, which -- with a little pruning -- can add architectural interest to the garden. Gardeners troubled by the buddleia’s sometimes unruly growth pattern should opt for dwarf versions.
The butterfly bush is also available in different colors. Various shades of purple are the most common, but white, pink and red variants are easy to find. Whatever the color, whatever the size, butterflies, bees and hummingbirds love the blooms. Perhaps the unique smell of Buddleia davidii’s flowers -- variously described as honeyed, fruity or subtly spicy -- is what makes the racemes so appealing.
A butterfly bush (or two or three) is the perfect centerpiece to a butterfly-friendly, deer-resistant, cool colored garden bed.