How about growing this: Coralberry

The purple-pink fruits of coralberry (Symphoricarpos orbiculatus) remain vibrant all winter.

I garden for wildlife, so many of my favorite shrubs—serviceberry, elderberry, grey dogwood–are the ones whose berries the birds devour the second they ripen. But there’s something to be said for a shrub that holds on to its abundant and very pretty berries all winter long. And few shrubs can beat coralberry.

Coralberry in winter . . .

Coralberry (also called Indian currant–the Latin name is in the first photo caption above) would be a useful plant even if it didn’t provide so much winter interest. It’s a low-growing shrub (most commonly no more than 3 feet tall, although older plants can be taller) that suckers to form large colonies. It prefers full to partial shade and is not fussy about soil. I use it to fill in shrub islands: I plant it between and in front of taller shrubs and trees to eliminate bare spots. Because it puts up lots of slender stems, it does a good job of holding groundcover or mulch in place, and it would be an excellent plant to use to hold a slope.

Coralberry blooms in late summer with tiny greenish-white flowers that are inconspicuous to humans but highly attractive to pollinators. According to the Xerces Society, it’s a particularly useful plant for attracting native bees. Add to that its usefulness at providing winter cover and winter color. How about adding some coralberry to your garden next spring?

. . . and in late summer, just after setting fruit

Mixed-species foraging flocks

Downy woodpecker. Copyright Ronaldok

In winter, it’s common to see mixed-species foraging flocks moving swiftly through the landscape. These flocks are composed of birds of different species that feed together. Common members of mixed-species flocks include nuthatches, titmice, chickadees, juncos and other sparrows, kinglets, and downy and hairy woodpeckers (side note: there are a lot of woodpeckers around this winter). You’ll find numerous theories about why birds form these flocks: as with any flock or herd, there’s safety in numbers; also, because they’re all looking for different foods in slightly different ecological niches, they don’t compete, and they help each other forage.

Birds are quite specific when they forage: some are ground feeders, some feed on branches, etc. So in a mixed-species flock, some birds will be searching the standing perennial stalks for remaining seeds while others forage on the ground for fallen seeds and insects. Each species may lead the others to sources of food, but they don’t compete. An ecological garden with many species of native plants, including grasses, perennials, and shrubs, is the perfect habitat for these flocks. From the birds’ point of view, this type of habitat is greatly preferable to artificial food sources like feeders.

White-breasted nuthatch. Copyright Jim Paris

Welcome back, forests

A mature red maple forms part of the canopy of the native wetland forest at the Thielke Arboretum in Glen Rock, NJ. Besides storing carbon, this forest provides other valuable ecosystem services, not least of which involves preventing floods by absorbing and slowing the movement of surface water after storms.

Today’s New York Times features a fascinating and hopeful article about the restoration of forests worldwide. To slow climate change, governments and conservation groups are making concerted efforts to restore forests, which sequester carbon and serve many other important ecological functions. And these efforts are beginning to bear fruit. Read the article, consider helping one of the groups involved in the efforts, and, once the bustle of the holidays is over, visit a nearby forest.

Happy holidays to all.

Radical rejuvenation

before . . .

Rejuvenating a shrub is the process of removing old stems to reduce the plant’s size and increase its vigor. Reduction, in contrast, means removing just a few large stems to reduce the plant’s size. To rejuvenate a shrub, you remove about a third of the stems each year for three years. Most shrubs require rejuvenation at some point, as they outgrow their space or become leggy. Because I planted a lot of shrubs on my small property, I pretty much have to rejuvenate continuously. And because last winter was too brutal for much pruning, my shrubs are in dire need of reduction/rejuvenation. So I started early, and here’s what one ninebark (Physocarpus opulifolius) looks like before (above) and after (below) pruning.

Note how crowded the plant at the top of the post looks. The largest stems are about an inch in diameter, and the plant is about 8 or 9 feet tall. It’s part of a hedge that was originally planted with coralberry, small hemlocks, two species of viburnum, and elderberry, in addition to the ninebark, with spring-blooming perennials below. Because of the ninebark’s large size and dense foliage, the other plants were getting shaded out, and because everything was so crowded, the ninebark itself developed an ugly case of powdery mildew last summer. So this winter I decided on radical rejuvenation: I removed much more than a third of the stems. On some plants I removed half or more.

Here’s the same plant after pruning:

. . . and after

The structure is the same, but the plant is considerably shorter and more open. I will be pruning all my shrubs, plus those of clients, in much the same way over this winter. I look forward to lots of young, vigorous growth in spring!

Gifts for gardeners: Part 3

As the time for purchasing holiday gifts is getting short, consider making a donation to an environmental group or purchasing a membership for your gardening friends.

Let’s start locally. The Thielke Arboretum here in Glen Rock is very dear to me. It contains a beautiful native wetland forest that a group of dedicated volunteers work hard to preserve. A new individual or family membership costs only $25 or $50. Or perhaps you have a local group that’s dear to you. If you’re not familiar with the many local environmental groups, check the Nature Program website for links to many groups in Bergen County. Or purchase a gift membership in the Native Plant Society of New Jersey, a group with many interesting educational programs and great resources for gardeners.

New York City is home to two world-class botanical gardens, and both have wonderful native plant gardens created in the past two years. The New York Botanical Garden, located in the Bronx, is larger and quite easy to get to from New Jersey. It contains the only remaining virgin forest in New York City as well as extensive greenhouses and plant collections from around the world. The Brooklyn Botanical Garden has a new educational building with a fascinating green roof as well as a small but diverse native plant garden. Both run excellent classes for gardeners at all skill levels.

National organizations you might consider include (but certainly are not limited to) are the Audubon Society (which has a very active Bergen County chapter) and the Lady Bird Johnson Research Center, an excellent resource for gardeners interested in native plants.   

And finally, don’t forget that Prairie Nursery, an excellent native-plant nursery located in the midwest, is offering 10 percent off on gift certificates through December 24!

One of my “prairie” borders in June. Most of these plants originally came from Prairie Nursery.

Books for gardeners: Part 2

This post lists the best reference books for gardeners. Yesterday’s post described books about the philosophy of ecological gardening.

I turn first to field guides for choosing plants and deciding what plants to put together in hedgerows and perennial borders. Pick your favorite series; I prefer Peterson, because I think it’s easier to identify plants in the field from drawings than from photos of specific individuals, and because nonnative plants are marked as alien. I use the guides to eastern butterflies, eastern wildflowers, shrubs and trees, and fungi almost daily. A particularly useful volume is the guide to eastern forests, which covers forest succession and types of forests. For grasses, Lauren Brown’s Grasses: An Identification Guide is extremely useful. And when I am helping local environmental groups identify the plants growing on their sites, I carry Weeds of the Northeast by Uva, Neal, and DiTomaso in addition to my field guides.

The indispensable guide to vegetable gardening is the aptly named Vegetable Gardener’s Bible, by Edward C. Smith. Whether you’re new to vegetable gardening and don’t know a brussels sprout from a raised bed or have been tilling and harvesting all your life, this book will give you great information. Smith concentrates on healthy soil and organic methods, the key to any kind of gardening.

For perennials gardens, a great general reference work is The Well-Tended Perennial Garden: Planting and Pruning Techniques, by Tracy DiSabato-Aust. It includes detailed growing techniques and an encyclopedia of plants (not concentrating on natives). For woody plants, the best reference work (also not concentrating on natives) is Dirr’s Encyclopedia of Trees and Shrubs. This book is huge and pricy, but I couldn’t do my work without it.

Finally, for pruning techniques, the textbook we used at NYBG is An Illustrated Guide to Pruning by Edward F. Gilman. It’s probably more detailed than most hobbyist gardeners need, but its instructions and illustrations are clear and easy to follow.

Pruned hazelnut shrub, showing detail of stems cut with a handsaw, the cuts made close to the ground and at an angle. I pruned this large plant last winter and will need to prune it again this year.

Books for gardeners: Part 1

The books described here will help you create a landscape that is friendly to both you and nature. This backyard, based on native plants, is welcoming to a wide variety of birds and other creatures and highly livable for the people who created it.

If your favorite gardener is interested in native plants and sustainable gardening, he or she would love to receive one of these books as a holiday gift:

Start with Sara Stein. That’s what I did. Nearly 20 years ago, I picked up a paperback called Noah’s Garden: Restoring the Ecology of Our Own Back Yards, and my life was changed forever. It was followed a couple of years later with a large, hardcover, color book, Planting Noah’s Garden. Taken together, these two beautifully written books tell you not only why to garden with native plants and in harmony with nature but also how. They are out of print, but certainly not outdated, and copies are listed on Amazon and other suppliers of out-of-print books.

Doug Tallamy published Bringing Nature Home: How You Can sustain Wildlife with Native Plants in 2009. Tallamy doesn’t have Stein’s gifts as a writer, but he makes a strong and well argued case for planting species that have the greatest wildlife value in order to restore our local ecosystems. Tallamy is an entomologist, so for him everything starts with the insects. This year he coauthored, with Rick Darke, a much more elaborate and detailed book, The Living Landscape: Designing for Beauty and Diversity in the Home Garden. If you can’t find Planting Noah’s Garden, that would be a great choice as a guide to native and sustainable planting.

Yesterday I had the privilege of hearing Carolyn Summers speak at the monthly meeting of the landscape architecture alumni group at the New York Botanical Garden (and I walked through the new native plant garden in winter–it’s still gorgeous). Her book, Designing Gardens with Flora of the American East, is another excellent primer. She shows you how to create a garden in any style–Japanese garden, English cottage garden, New American garden–using native plants. So if you would like to use more native plants but prefer a traditional style, this book is for you.

Tomorrow I’ll post about some excellent reference books for the gardener on your list–or maybe for you.

Winter residents: Juncos

Photo copyright Christopher L. Wood

Dark-eyed juncos (also called slate-colored juncos), like many migratory birds, fly south for the winter, but they don’t head for Florida or Central America. They breed and spend the summer in the Arctic and come here, to the temperate latitudes of North America, for the winter.

Juncos are sparrows with distinctive slate grey and white coloring, as if their bottom halves, including the undersides of their perky tails, were dipped in milk. They arrive in mid-fall and feed in my backyard all winter long. They are ground feeders, so they spend a lot of time sifting through the leaf litter; when the ground is covered with snow, they’re particularly easy to see as they move through the perennial stalks looking for food. They enjoy my woodland floor as well. Occasionally they join mixed species foraging flocks, but they most often seem to feed in small single-species groups.

12/12/14: In the garden this week

American hazelnut (Corylus americana) after pruning last winter. Notice the newly cut stems at the bottom center.

It’s just about time to start winter pruning of trees and shrubs. The temperatures have generally gone below freezing overnight, so even through the ground is not completely frozen, most plants are dormant. In horticulture school, we learned to start pruning after Christmas and end sometime in February when the sap starts to run. Last winter that meant pruning in freezing cold temperatures, with snow and ice on the ground. Consequently, I have a lot of pruning to do this winter!

The bird activity continues apace in our front and back yards. We’re still trying to get pictures of the mixed species foraging flocks. Look for a post on them in the near future. In the meantime . . .

– stop watering newly installed perennials and woody plants. We’ve had a lot of precipitation lately; my informal rain gauge (an open one-quart yogurt container) is full, and its contents are partly frozen. If we have a prolonged period of warm, dry weather, however, resume watering so that new plantings receive 1 inch of water per week.

– begin winter pruning of woody plants. Most trees and shrubs are now completely dormant, so this is a good time to prune. I prune shrubs myself but call a tree company for larger jobs. Don’t go crazy with removing dead wood, however: large dead branches and snags (standing dead trees) are the best possible homes for birds. We have two large Norway maples that are slowly dying of wet rot. We have dead branches removed if they’re over walkways or buildings but leave others alone. Woodpeckers have been living in the trees for years, and now there are nuthatches as well.

– thoroughly clean up the vegetable garden. Do not compost diseased or pest-infested plants. Spread a layer of compost to prepare the soil for next year.

– leave seedheads in place on perennials and native grasses and enjoy the bird activity all winter.

– save your autumn leaves for compost. Store them to add to the compost pile all year. You may also decide to use your lawnmower to chop them and mulch them into your lawn as fertilizer.

A male red-headed woodpecker in residence in a dead branch of one of the Norway maples in our front yard. This picture was taken in spring of 2011. There’s been a nest in this branch every year.

The first seed catalog of the year

arrived in the mail today. Surely to a gardener this marks an important shift in the seasons, like the first crocus or robin of spring? It was Fedco Seeds of Maine’s seed catalog. Fedco specializes in cold-hardy varieties of vegetables, flowers, perennials, and trees, and as a nonprofit coop, is dear to my heart. I order most of my vegetable seeds from them.

Another company that’s very dear to me because of many years of excellent products and good service is Prairie Nursery, which is located in Wisconsin. (I with they were here in the east, but they’re not. If you order from them, make sure the plants you choose are native to your region as well as to the midwest.) Right now they are offering 10 percent off on gift certificates. Think about that if you are looking for a great gift for a gardener.

Virginia bluebells (Mertensia virginica) from Prairie Nursery. If you have moist soil and a shady site, you can grow this lovely native spring ephemeral.