Native plants support wildlife and offer beauty in your garden
In recent years there has been a real upsurge in the use of native plants in the landscape as a way to support pollinators, birds and other wildlife. This is due, in part, to the fact that native plants are recognized and used by our wildlife, while most foreign species of plants are not. For example, birds generally nest in native trees and shrubs, but avoid those originally from Europe or Asia, and caterpillars rarely are seen on any imported species of plants. Not only that, most natives are hardy and lovely.
Scientists have found that birds depend on the caterpillars of butterflies and moths as the primary food source for baby birds. No caterpillars? No birds nesting. Entomologist Dr. Doug Tallamy found that a clutch of chickadees needs 6,000 to 9,000 caterpillars to survive from hatching to fledging. So let’s take a look at some common native perennials, trees and shrubs that are handsome and easy to grow.
According to Dr. Tallamy, the best perennial for pollinators is goldenrod. There are many species of goldenrod. Some of the wild types are not suitable for garden beds as they spread by root and easily elbow out plants we also want. But there are some nice ones readily found for sale at nurseries and that do not spread like crazy.
My favorite goldenrod is a variety called ‘Fireworks.’ It grows to be 2 to 4 feet tall and stays in a nice clump that does increase in size but is not aggressive. It does best in full sun with damp soil, but will take some shade and dry soil.
The Mt. Cuba Center is a research center in Hockessin, Delaware, that trials and rates native plants. They rate ‘Fireworks’ goldenrod as the very best, a 4.6 out of 5.0. Another one I like is a dainty little goldenrod called blue-stemmed goldenrod (Solidago caesia) that grows well in dry shade, blooming late in the fall. For me it stays about 18 inches tall.
You probably know that monarch butterflies need milkweed for their caterpillars. The milky alkaloids in milkweed are ingested, making the caterpillars distasteful to predators. But common milkweed, the wild one, spreads aggressively by root and seed, making it a problem for most gardeners. The answer? Buy swamp milkweed (Asclepias incarnata). This comes with pink blossoms (or sometimes white ones) and stays in a nice 3- to 5-foot-tall clump. Other pollinators enjoy the nectar and pollen of this fine plant, too. It does best in moist soil, but will grow in ordinary garden soil. It blooms in early to mid-summer.
One day last September we were visited in our garden by hundreds of migrating monarch butterflies. Just like marathon runners, monarchs need lots of calories before their long trip. These were feeding on nectar from a late-blooming native plant, Joe Pye weed (Eutrochium spp.). I’d not seen so many monarchs all at once in 30 years or more.
There are several species and cultivars of Joe Pye weed. All do best in full sun or partial shade, and consistently moist soil — though I’ve read that they will tolerate ordinary garden soils once well-established. Most Joe Pye weeds are tall — 5 to 8 feet tall — and develop into large clumps. Blossoms are purplish to pink, lasting for several weeks in the fall. Their seeds are eaten by birds in winter if you leave the stalks uncut in the fall.
My favorite Joe Pye is a variety called ‘Gateway.’ It has purple stems and the blossoms look good in a vase longer than the wild ones I also grow. There are two varieties that are claimed to stay short, one called ‘Baby Joe’ and another ‘Little Joe.’ Both are said to grow to just 3 feet, but I haven’t grown either one.
Goldenstar or Green and Gold (Chrysogonum virginianum) is a nice, low native that does well as a groundcover. It blooms with 1-inch bright yellow flowers in early June for me, but also re-blooms off and on throughout the summer. It does fine in shade or part shade with rich, moist soil. If the soil stays moist, it will grow in full sun, though it will go dormant in the heat of summer. Each plant can cover a circle about a foot in diameter. Look for it in better nurseries: It is not a plant you’ll find in a big box store. It is native to Pennsylvania but is hardy in all but the coldest pockets of New England.
All wildflowers are native, and many are called ephemerals because they disappear after an early spring flush of flowers. All are important for native pollinators and beneficial insects because there are few sources of pollen or nectar in a New England spring. A good selection of wildflowers are available at The Garden in the Woods in Framingham, Mass. The Garden in the Woods is a nonprofit garden, education center and plant nursery run by The Native Plant Trust, formerly called the New England Wild Flower Society.
One of my favorite spring ephemerals is Dutchman’s breeches (Dicentra cucularia). This is a low-growing plant with delicate, finely divided leaves and white blossoms that look to me a bit like pairs of white long underwear! Mine is growing under an old apple tree in partial shade and deep, rich soil. It only blooms for a couple of weeks.
If you see a bumblebee at this time of year, it is a queen that has overwintered. They love Dutchman’s breeches and other early wildflowers — they use the pollen to feed their worker bees that are growing into real workers, so the queens can retire to a life of luxury.
Dutchman’s breeches have two relatives that you may know or grow: bleeding heart (Dicentra spectabilis) and wild or fringed bleeding heart (Dicentra eximia). Some books say both are natives, others say Dicentra spectabilis is native to Asia, or native both here and there. It dies back in late summer.
I’ve seen wild bleeding heart (Dicentra eximia) growing in the wilds of Vermont, though it is not common. It is an unusual wildflower because it keeps its foliage all summer and blooms on and off all summer. It is much lower-growing than its bigger cousin and has nice finely divided delicate-looking leaves. Both of these plants are readily available in nurseries.
If you live in suburbia with a big lawn and want to support wildlife, think about giving up some lawn and planting native trees. Trees really are the workhorses of the plant world. They have more leaves and greenery than our annual and perennial plantings, and hence can let moth and butterfly larvae munch their leaves — and you will probably never notice. Before you plant any full-sized tree, do your homework. Learn how big it will get and leave plenty of space for it.
According to Doug Tallamy’s excellent book, Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard, the very best trees to plant to support wildlife are the oaks. There are 90 species of native oaks that grow in the United States, and all are excellent. Of these, the white oak (Quercus alba) is the best. It commonly grows wild in the Northeast and it supports many more species of caterpillars than any other tree. Not only that, it grows to be a huge tree, one that can live for hundreds of years. So the white oak is also great at sequestering large quantities of carbon from the atmosphere, helping to reduce global warming.
If you want to plant a white oak, do not be deterred by how long you think it might take to grow. If you can afford a tree that is already 6 to 8 feet tall, it will be 20 feet tall inside of five years. Or if you are young and patient, you can plant acorns. At this time of year, or soon, you should be able to find and dig up seedlings that are just starting to grow. Oaks send down deep taproots, so digging up bigger plants is more difficult.
The only downside to white oaks, from my perspective, is that deer love to nibble on them when the trees are young — much more so than red oaks, which are also good native trees to grow for wildlife. If you plant a white oak and have deer in your vicinity, the safest way to protect it when young is to surround it with a wire mesh fence.
However, I have planted white oaks where deer are a problem and did not fence them. Instead I relied on a repellent device that clips onto twigs like a clothespin. It is called “Fend Off Deer and Rabbit Repellent” and contains garlic extract in small cylinders. Once you puncture the seal inside the capsule, it emits a strong odor that deer hate. These repellents last for over six months. I’ve seen footprints of deer going right up to white oaks with these garlic oil repellents — and then walking away without taking a bite.
Oaks have very strong limbs and can send out limbs that are almost parallel to the ground, sometimes 20 feet or more in all directions. So do not plant your tree near the house. It is a good “specimen tree” suitable for the middle of your back lawn, or protruding out from the edge of a wooded area. White oaks do not do well in areas that have poor drainage. For such an area, choose a swamp white oak (Quercus bicolor). They also do well in ordinary soil.
We all know and love the sugar maple (Acer saccharum) for its great fall colors and delicious syrup. Unfortunately it is not a perfect choice for suburban landscapes. It is not tolerant of pollution, compacted soils or salt. It does not tolerate long periods of wet soil. It struggles in soils low in calcium. It is better suited for rural areas where it grows wild.
If you want a maple tolerant of soil compaction and suitable for soils from wet to dry, sandy to clay, our native red maple (Acer rubrum) is a good choice. It is relatively fast growing and shows off bright red leaves in the fall. It does not tolerate road salt, so it is not a tree to plant near a paved road. But almost anywhere else? It’s a great tree.
According to the terrific book Essential Native Trees and Shrubs for the Eastern United States by Tony Dove and Ginger Woolridge, the red maple supports 300 kinds of caterpillars as well as providing nectar while blooming in the early spring. Some varieties have male and female trees, but others have flowers of both sexes on the same tree. The seeds on female trees are important for birds and small mammals.
For smaller properties there are many fine native shrubs to choose from. One of my favorites is mountain laurel (Kalmia latifolia), the state flower of Connecticut. I grew up with it blooming in hardwood forests with a high canopy — mature oaks in particular. I did a lot of off-trail hiking as a boy and always stopped dead in my tracks when I came upon mountain laurels in bloom. Here I have planted three of them as they are hardy but are not found in the wild near me.
Mountain laurel, I have read, is not an easy shrub to grow, but my own experience is different: I planted my first one on a moist hillside with morning sunshine and acidic soil. It has thrived and blossomed nicely for decades even though I do nothing for it. It is a relatively slow-growing shrub, 6 to 12 inches per year. In the wild they can grow to 10 or 12 feet in height, but they stay smaller in cultivation.
Mountain laurel is in the heath or heather family, so it needs soil that is quite acidic, pH 5.5 or so. When planting, dig a nice wide hole and add sulfur or soil acidifier to the soil. It’s best to use a pH test kit to determine the soil pH, and then add acidifier as directed on the package to bring down the pH. Adding peat moss at planting time will help, too. Mulch with pine needles if you have them.
The mountain laurel has glossy green leaves that are a bit like those of rhododendrons. They look good all year. But then, ka-boom, the buds and flowers appear in June. The blossoms appear in clusters, which open up to small cups, often with a mixture of pink and white inside, though there are some varieties that are deep rose throughout.
Hydrangeas are well-loved shrubs for home gardeners, though many of them are not native. According to the Mt. Cuba Center, the best native is one I grow, a smooth hydrangea (Hydrangea arborescens) called Haas’ Halo. This is a relatively new selection with lacecap flowers in mid-summer. The flowers have both fertile and sterile blossoms on flat-topped corymbs 4 to 8 inches across. Bees and other pollinators flock to it when blooming. In the wild, smooth hydrangeas are found in woodlands, and this one will boom well in either sun or shade, and tolerates dry soils well.
The best-known smooth hydrangea is ‘Annabelle,’ which I don’t use because the first time the blossoms get rained on they flop to the ground. Not so with Haas’ Halo. It has sturdy woody stems that hold up its blossoms well. Even after the flowers go by, the dry floret looks good into the fall and winter. Though I have seen reports saying it is not attractive to deer, I have seen deer demolish young Haas’ Halo shrubs. I cut the stems right to the ground in late winter or early spring as they bloom on new growth, and this keeps the shrub from getting too lanky.
My last pick for a handsome native shrub is Common Sweetshrub (Calycanthus florida), which is native to Pennsylvania and south through Florida, but hardy here to Zone 4. It does best in part shade with well-drained rich loam — but will grow in clay soil and survive in full sun if given adequate moisture. I have had it scald in full sun, so I don’t recommend that.
Common Sweetshrub’s claim to fame is the strong fragrance of its wine-red 1- to 2-inch flowers. I suggest you buy one in bloom if fragrance is important to you. I have two specimens, both of which have only a minor fragrance. But the blossoms are delightful to look at, and they are vigorous plants. It provides pollen to bees and the leaves are eaten by caterpillars.
Although statistics vary, most authorities agree that at least 50 percent of Americans do at least a little gardening. If all of us planted a few native plants, it would help our birds and pollinators to thrive. Remember, native plants co-evolved with our native animals over millions of years. They are wired to recognize and use natives. So strive to plant more natives this year!
Henry can be reached by e-mail at henry.homeyer@comcast.net. If you’ve grown some of these plants, feel free to e-mail him and give a report on how yours did.
