Flowers are the fun part of the garden, giving color, fragrance and help to bees and other wildlife. The most striking flowers come on small trees and shrubs, because they are at human eye level and cover a mass of space on a single plant.

Plant these dozen shrubs, and you can have color in your garden for nine months or longer, from March through October. They aren’t the only flowering woody plants you may want, but they will give you a good start toward a showy perennial border.

The most surprising, and earliest, is witch hazel, which blooms either very early or very late in the season. Hamamelis intermedia, a Japanese species, blooms in March in Southern Maine most years. Portland’s Post Office Park is home to a highly visible example. Cultivars (or named varieties) include “Arnold’s Promise” and “Pallida.” One native witch hazel, Hamamelis virginiana, blooms in November or December, but the blooms are insignificant; another native, Hamamelis vernalis, also blooms in late winter.

Magnolia soulangeana, the saucer magnolia, is the next shrub in the progression. Yes, a shrub garden may have a flowerless period between the witch hazel and the magnolia, but console yourself with early bulbs, such as crocus, during that period. If you want to extend the magnolia season, plant stellata magnolias, which are white, and the yellow-flowering acuminata hybrids; “Elizabeth” is my favorite.

The editor who in 2004 first asked me to write a garden column always pestered me to write about forsythia. I resisted because most years in Maine the branches of the forsythia that weren’t covered with snow failed to bloom, so the shrubs had blossoms about two or three feet above the ground and no blossoms above that. Well, winters have been getting warmer, and if you plant “New Hampshire Gold,” developed in our neighboring state, or “Northern Gold,” a Canadian cultivar, you should be OK.

Lilacs aren’t native, but are lovely and well-behaved. Common lilacs, Syringa vulgaris, come in purple and white, and hybrids can be pink or almost red. My wife and I love to bring blossoms inside because of their lovely sweet aroma. They always make me think of Whitman’s elegy to President Lincoln – the kind of leader we could use now. To extend the lilac season, plant Syringa josiflexa varieties “James MacFarlane” or “Agnes Smith.”

Ninebark (Physocarpus opulifolius) is a native Maine shrub – I often see the species in the woods when I’m fishing. But it didn’t become a popular garden plant until cultivars such as “Diabolo” and “Summer Wine,” with purple to red or golden foliage, came on the market. Cultivars range from 8 feet tall for “Diabolo,” my personal favorite, to 3 feet for “Tiny Wine.” Blossoms start out white in late May or early June and darken over the summer. The exfoliating bark provides winter interest.

Rhododendrons are divided into small-leaved and large-leaved varieties. The small-leaved varieties include the PJM rhododendron with bright lavender flowers named for Peter J. Mezitt, who developed it in Weston, Massachusetts. When it blooms in May, it is visible on every suburban street. It’s a hit partly because it’s one of the few rhododendrons that will stand full sun. Large-leaved rhododendrons bloom later, grow taller and are overall a better plant for shade. The Rosebay variety can grow 12 feet tall, and Independence blooms near the Fourth of July.

Viburnum is a wide-ranging family of plants. Many are native to Maine, but there are also attractive varieties that come from Europe and Asia. The flowers are usually white and come in late spring or early summer; the foliage often turns a brilliant red in the fall; and the berries can be red, blue or black and last all winter.

Our garden has a snowball viburnum we planted in 1976, which died back to its roots when the viburnum leaf beetle first hit, resprouted from its roots and is now doing well. My favorite is the native “Mohican” for its blossoms, long-lasting fruit and fuzzy buds that last through the winter.

Weigela is another well-behaved non-native. It comes from East Asia and has dense, pink flowers and colorful fall foliage. The plants range from 12 inches tall for the fairly new “My Monet” to 5 feet for “Wine and Roses.”

Spirea took off as an indispensable garden plant with the introduction of “Anthony Waterer,” a tough, reliably blooming 3-foot-tall plant with rose red blossoms that begin in late June or early July and will continue through late September if you prune off the spent blossoms. My favorite is “Magic Carpet,” with pink flowers and foliage that starts red and turns to gold.

Hydrangeas became the rage about 20 years ago – although they have been in gardens for generations. Maine gardeners have had some trouble getting the “Endless Summer” series to bloom reliably, although they are highly popular. My favorites are the old-fashioned, full-size hydrangea paniculata “Tardiva,” which blooms a little later than others, and hydrangea arborescens “Annabelle,” which has bloomed profusely in a shady part of our garden for more than 40 years. The blossoms remain through the winter in sort of a cream/tan color.

The rose of sharon, a hibiscus shrub, grows up to 12 feet tall, can stand quite a bit of shade but loves full sun, and produces large, showy flowers in late summer. Blossoms can be white, pink, red, lavender or a mix. It is a Zone 5 plant, so won’t survive except along the coast of Maine. Yes, the blooms look like the tropical hibiscus blooms in more sedate colors. And yes, there is a perennial, herbaceous version of hibiscus as well, just to add to the confusion.

Clethra is a native shade-loving plant that produces graceful, arching and highly fragrant flower panicles. The blossoms can be various shades of pink or white. The shrubs prefer moist soil but can stand dryness. Clethra also has good fall foliage, sort of golden yellow to orange.

If you care enough about gardening to be reading this column, you probably have at least half of these plants in your yard already. I’m just tempting you to add more of them.

Tom Atwell is a freelance writer living and gardening in Cape Elizabeth. He can be contacted at 767-2297 or at: [email protected]