Trees and shrubs are the backbone of most gardens. They provide height, structure and (sometimes) interest all year long. But if your garden is smaller—as mine is—finding right-sized shrubs is a challenge. That's when I turn to perennials that act like shrubs.
These are perennials with some height (3 feet or more) and some heft. They should have a moment each year in which they shine but look good whether it's their time in the spotlight or not. Unlike shrubs, these perennials do not require pruning because they dieback in the fall. They are also well-behaved in the garden and don't spread relentlessly.
Here are five northern perennials to consider the next time you are looking for a shrub:
Baptisia. False indigo (Baptisia australis) is one of my favorite plants for many reasons. First, the bees love it. Bumblebees, particularly, are all over this plant when it is in bloom. It stands about 3 to 4 feet tall and about 3 feet wide at the top once it is mature. You can put a hoop around it, but generally it does not need support or even much care. It handles drought well, and deer stay away. What's not to love? After the pretty flowers fade, the plant develops a large, nearly black seedpod that hangs on through winter. When the wind blows it sounds like castanets in your yard! Baptisia has been the subject of a lot of breeding work, so you'll find many cultivars to consider. Twilite Prairie Blues, a variety from the Chicago Botanic Garden brings a deep purple color to the garden when it blooms. 'Lemon Meringue' is a more diminutive cultivar with yellow flowers. You can also find baptisias in reddish and cream tones.
Peony. It's peony bloom time in Minnesota, so these shrublike perennials look especially stunning, but peonies are a pleasant presence in the garden all season long. Whether tree peonies or herbaceous, peonies have large, dramatic leaves. Once established, they are very easy care, asking only for some sun, well-drained soil and an occasional hit of fertilizer. Best yet, peonies are integral to Minnesota history and there are thousands of varieties available. Choose early, middle and late bloomers to extend the peony season.
Amsonia. No one is growing Arkansas blue star (Amsonia hubrichtii) for its bloom. The small, blue, star-shaped flowers appear early in the season and are sweet but not showy. Amsonia, which was Perennial Plant of the Year in 2011, is grown for its ferny foliage and perfect size. The perennial grows to 3 to 4 feet tall and wide early in the season and adds a textural element to the flower border. It sways with the wind and its soft green color glows in certain lights. It's exceptionally pretty in fall when the foliage turns bright gold. Amsonia is hardy to USDA Zone 3 and grows well in partial shade or full sun, if the soil is moist. Add some compost or mulch the plant with shredded leaves for the best growth.
Joe Pye weed. This native, prairie plant can stand in for a tall shrub in a sunny location with fairly fertile soil. Joe Pye weed (Eutrochium maculatum) is tall and somewhat narrow, growing up to 8 feet tall and 2 to 4 feet wide. The foliage is a bit rough, so it might work best with other plants in front of it. The large purple flowers are stunning and very attractive to bees and butterflies. 'Little Joe' is a popular cultivar that grows to about half the size of the species. If your situation is shadier, you might consider sweet Joe Pye weed (Eutrochium purpureum), which grows 4 to 7 feet tall even under trees. Joe Pye weed is another great deer-resistant plant.
Goat's Beard. I've never grown goat's beard (Aruncus dioicus), but I've seen it in many tour gardens, where the white plumelike blooms rise about the foliage like astilbe flowers. Goat's beard is a member of the rose family and native to Wisconsin and much of the Midwest. Plants generally grow 4 feet tall in clumps. It can spread, so keep that in mind.
These are just a few of the perennials that bring a shrublike presence to the small garden. Which ones do you like best?