I’ve been writing this column week in and week out for more than 13 years, so I’m always grateful for ideas from readers. When reader Rachel Dyer of Augusta wrote to say her online search for shrubs that can thrive in shade and in seasonally moist conditions had yielded nothing, I knew I had an interesting new topic.

Many gardeners deal with shade. A house itself will shade at least one side of the garden, and while trees add blossoms, shelter for wildlife, beautiful foliage and more, they bring shade, too, of course. But that’s not a bad thing. A shade garden actually replicates the kind of landscapes that we find in nature. Much of Maine is forested, and the native plants that grow on the edge of the forest or in openings in the middle of the woods have to be able to tolerate shade.

Working on this column brought home to me that if your property has a moist, shady spot, it’s still possible to create an attractive garden of shrubs, one that provides blossoms from early spring to fall, and that offers some handsome evergreens as well as unusual-looking foliage. I’ve written up a list of plants I’d suggest. Most are native, the sort that Maine gardeners these days increasingly seek out. Your local nursery will offer plenty of other possibilities to choose among, too, but these are plants with which I have some experience. All are nice to look at and – so far at least – are reasonably pest-free.

“Ruby Spice,” a cultivar of Clethra alnifolia, keeps its blossoms through the fall.

• Clethra alnifolia is a must for native shade gardens. The full-size versions, including the species (meaning the plant as it’s found in nature) and several cultivars will grow 6 feet tall. That group includes Cary Award winner “Ruby Spice” (the award is given to outstanding New England plants). Compact types are as small as 21/2 feet. They bloom in late summer and keep their blossoms throughout the fall. The blossoms are “bottle-brush” shaped, about 6 inches long for most cultivars, and come in shades from pink to white. One of Clethra’s nicest attributes is its sweet, pervasive fragrance.

• Mountain laurel, or Kalmia latifolia, is another must-have shade-tolerant native. The full-sized cultivars grow about 8 feet tall, but dwarf cultivars are as small as 3 feet. Kalmias like moist but well-drained soil. They will survive and blossom in full shade, but they blossom more heavily – usually in May or June – if they get some sun. Mountain laurels are evergreen, with glossy leaves you can enjoy year round.

• Kalmia augusifolia or sheep laurel, is, at 3 feet, a smaller plant. It prefers soggier conditions but still likes shade. My wife Nancy and I planted our first one earlier this year. Kalmia are close relatives of two of the most common – but mostly non-native – shade plants, rhododendron and azalea.

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• A native rhododendron, rhodora, has white or rose-purple flowers and its maximum height is about 3 feet; it likes shade and moist conditions.

• Rhododendron maximum or the rosebay rhododendron, is also a native but falls at the other end of the size spectrum. It can grow 12 feet tall.

• Many experts (me among them) consider the bottlebrush buckeye, or Aesculus parviflora, the best midsummer flowering shrubs for shady areas, growing 8 to 12 feet tall with white flowers. The foliage turns a pretty yellow in the fall. In ideal conditions, it produces pear-shaped nuts called buckeyes, but don’t count on any this far north. We planted one from bare-root stock under our neighbor’s Norway maples early this spring, and it has survived thus far.

• We also planted two witherod viburnum, Viburnum cassinoides, this spring. Both have survived, and one even produced a couple of berries, though we’ve only just planted it. If you’re looking for a viburnum that tolerates shade, the witherod viburnum is the most commonly available variety.

• Amelanchier, the shadbush, likes moist conditions but will take only partial shade. It grows about 20 feet tall, has white blossoms in the early spring and berries that birds like to eat. Ours has done well for 10 years getting sun only after about 1 p.m., so I would chance it for a shade garden.

• We planted an Annabelle hydrangea, Hydrangea arborescens, in our backyard shortly after we started landscaping our house in the late 1970s, and it has been one of our most successful plants. It produces huge white flowers in early July, and the flowers stay on all winter. We do have to prune it occasionally to keep it from taking over that side of the yard. In the years since we planted Annabelle, many new arborescens hydrangeas have been introduced with larger flowers, some of which are pink. I think they’d work well in a moist, shady spot.

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• As for trees, we’ve never grown Acer pennsylvani-cum, known as the striped or moose maple, ourselves, but it is an attractive plant that I have often noticed growing alongside the streams when I’ve gone fishing in Maine. It gets no higher than 25 feet, has huge leaves and striking green-and-white-striped bark. The new stems are slightly red. If it grows so easily in the wild, I am sure it would thrive in a home garden.

• Hemlocks are also a good option. While hemlocks – botanical name tsuga – grow up to 90 feet tall, some cultivars are much shorter. The white-tipped specimen that we planted in the 1980s is still only about 15 feet tall. It seems to like its shady site. Be aware that the hemlock woolly adelgid, a pest from East Asia that sucks the sap from hemlocks, has been destroying hemlock forests in southern New England and is already present in southern Maine. It has not yet been found in the colder parts of the state.

So as you can see, lack of light – even when coupled with moisture – is not really a problem for gardeners. You just have to know how to deal with it.

 


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