Trees & shrubs Ideas, Tips & Guides

I CONFESS to something of a weakness for Japanese maples, and I suspect I’m not alone. Now, thanks to breeding work by experts like today’s guests, there are more and more varieties being made available that are suited to a widening range of climate zones and garden conditions, meaning the circle of maple lovers can keep on growing.

I SUSPECT I’m not alone when I say that weather extremes in recent growing seasons have made me feel a bit like a stranger in a strange land in my own garden, wondering what will bloom when and when to do what. And most of all, wondering what madness is coming next.

IT’S HYDRANGEA SEASON, and in the Northeast in particular this summer, it’s really been a crazy hydrangea season, with billows of blue bloom from bigleaf hydrangeas on view everywhere, it seems—which is not always the case in colder hardiness zones. It seemed like a good time to review what makes hydrangeas happy, and what hydrangeas make me and my old friend, Ken Druse, happy.

WE’RE GOING TO talk about collectibles today, but not the kind you score at a flea market or from an online auction. We’re going to talk about collectible trees. Yes, trees. A new book by Amy Stewart called “The Tree Collectors” introduces us to 50 people whose lives have been transformed by what she calls their “arboreal obsessions.”

MOST PEOPLE call in an arborist when they think it’s time for a tree to be removed, a costly process both financially and environmentally, since trees are critical drivers of diversity. Today’s guest runs a tree-care company and also a tree-focused nonprofit that emphasize other services instead of removals, advocating for the planting of young trees, for caring for our trees with smart structural pruning, and regular inspections to get to know them better and stay ahead of any problems, and for thoughtful support of dead and dying trees as important forever members of our ecosystems.

EVERY GARDENER has their obsessions—or maybe a nicer way to say that might be to call it their “signature plants,” the ones that help define their garden. I confess to a serious issue with gold-leaved things. And last time I checked my friend Ken Druse had more than a few plants with variegated leaves of all kinds of daring patterns and hues that catch your eye in his New Jersey garden.

‘Color Guard’ was brought back from Japan by a man who knows a thing or two about foliage plants, hosta breeder Paul Aden of Long Island (who introduced ‘Sum and Substance,’ for instance, and so many other standouts). Despite the very different swordlike shape, its creamy-yellow-centered leaves are not unlike those of the most dramatically variegated hostas, but the yucca is a creature of sunnier spots.This is a perennial-like shrub for every day, and for gardens in most every zone, or at least Zones 5-10, growing in clumping fashion to 2 to 3 feet across and high. That is, except in spring, when 6-foot-tall stalks erupt with fragrant white bell-shaped flowers. Mine (still in its nursery container) has been showing off despite being “temporarily” plunged into a large pot on my terrace since May. It will

The plant was first discovered near Vladivostok in the 1920s, above the treeline, where it survived the deep cold of Siberian winters, making it a Zone 3-hardy creature, supposedly.Although it is a groundcover species, don’t expect it to grow in the dark: That was the mistake made at first when Microbiota reached the American market in any numbers maybe a decade ago. Saying a plant can handle some shade is different from saying it’s a shade plant; this one wants half a day of sun or more, I think, and wholesalers who propagate a lot of it say sun to part sun on their labels. In warmer zones, protection from afternoon sun is important, and in fact Microbiota isn’t a fan of the hottest zones at all.Though Microbiota (seen above in winter color) is said to have few if any pest and disease problems, I will confess to this: I have killed a number of them, without ever

First, the ‘Sensation’ lilac went mad, with some of its blooms going the palest of pinkish-whites (top). You’d think after 70 years or thereabouts as a named cultivar it would know what it was supposed to look like, but no. Then I saw a choice hosta called ‘Touch of Class’ go ’round the bend in a pot out back, sending up half of its foliage in blue, not blue with gold (below). ‘Touch of Class,’ which comes from the exceptional cultivar called ‘June,’ is even more vivid…well, at least it is when it cooperates and stays stable.My variegated kerria, Kerria japonica ‘Picta,’ reverts every year (above), bless its little heart, making sure I get to undertake the

I’ve stayed put long enough to outgrow my early mishaps, and have some favorite evergreens to share including the weeping Alaska cedar, which I have always known as Chamaecyparis nootkatensis ‘Pendula’ (above, in my far borders to the west of the house). Lately it has been placed in a new genus, Xanthocyparis, but my old habits die hard. Two weeping Alaska cedars grow here now, the first a 40th birthday present from my garden mentor; the other (above) a few years younger. Each one is about 25 feet. Though they are said to reach 60 or even 90 feet in the wild (Alaska to Oregon), half that is the exp

Fruit-tree pruning, as mentioned in the February garden chores, is a perfect way to get a mid- to late-winter jump on things.Cutting out infested Viburnum twigs loaded with viburnum leaf beetle egg cases before they hatch will reduce your problem with these tricky pests.The three D’s of dead, damaged and diseased wood, can always go, no matter the month. Survey the yard for such wood anywhere, on any plant. Eliminate suckers at the base of grafted trees and shrubs, like crab

I have said before that I know what birds like, and have created a slideshow of the variousCornus, or dogwood, species that I grow–all of them good wildlife plants. But since the berries produced by Cornus alba and Cornus sericea, both twig dogwoods, really don’t catch my eye, I was interested to see that gray catbirds and tufted titmice, in particular, are positively wild about the unassuming white fruit.I grow a few varieties of Cornus alba andC. sericea, including the variegated-leaf, gold-twig ‘Silver and Gold,’ the gold-leaf, red-twig sericea called ‘Sunshine’ (above, in fruit; Cornus

I noticed that my friend Bob Hyland at nearby Loomis Creek Nursery is counting his twiggy blessings, too, this week—with an ode on his website to Salix ‘Swizzlestick,’ a distinctive corkscrew willow he grows as a dramatic 60-foot hedge.I’m making myself content with much less, but even a little ‘Winter Flame’ (hardy to Zone 4) warms the winter-weary soul. My young plant hasn’t reached full size of 8-10 feet, though at 4 feet it produces a show of yellow-, orange- and reddish-tinged stems that read as coral to my eye.The Dutch breeder of ‘Winter Flame,’ Andre van Nijnatten, has also developed a smaller-stature version called Cornus ‘Arctic Sun’ that is earning high pr

I HAVE SAID IT BEFORE (BUT AM INCLINED TO REPEAT MYSELF): I prefer white Hydrangea to blue ones. And in this hottest, driest summer I know another reason why: The clean white blooms of my various Hydrangea paniculata freshen the place up a bit.

Early spring is the perfect time for this kind of project, when divisions of perennials are plentiful and there’s a long growing season ahead for everyone to settle in and get growing.Successful underplanting involves selecting the right mix of plants, and then being patient: There are 10 things I think about when I am tackling a new area, creating another botanical mosaic to cover the ground beautifully instead of a mass one one thing. Ready to create some of your own?Categoriesannuals & perennials for beginners garden design groundcovers shade gardening trees & shrubsTagsgroundcover

First, the disclaimer. I know I said the plant is specifically Pinus strobus ‘Nana,’ and that’s how mine came to me, but here’s the wrinkle: ‘Nana’ is kind of a grab-bag name for many relatively compact- or mounded-growing Eastern white pines, a long-needled species native to Eastern North America, from Canada to Georgia and out to Ohio and Illinois.Today, you can shop for named varieties that are really compact, with distinctive and somewhat more predictable shapes, like‘Coney Island’ or ‘Blue Shag’ (to name two cultivars selected by the late Sydney Waxman at the University of Connecticut, who had a particular passion for this species).I could have pinched the tips of the new growth, or candles, by half each year to keep

This long-needled pine, grown for its beautiful, peeling bark that resembles camouflage fabric, just gets better with age—or is supposed to, as long as it lives that long. But now in addition to substantial disfigurement left by an insistent male yellow-bellied sapsucker a year or so ago, my beautiful bark has giant divots in it, too (you can see both in the top photo). Weren’t the woodpecker’s rows of small holes and the oozing, now-blackened sap that poured out from them, enough for the one poor tree (and gardener)?Apparently not.A storm with high winds took two large branches and one smaller one from the pine a week or so ago, snapping them right o

Each Eastern tent caterpillar overwintered as part of a mass of several hundred eggs, and hatched in early spring to get ready to start eating. Fruit-tree foliage, including that of crabapples, is on their preferred diet, so I make a habit of destroying all the masses I can get to in my 10 crabapple trees, and elsewhere around the yard. I’m not going to single-handedly knock back the entire population, of course, but this simple, non-toxic tactic does reduce the damage to my trees so I can enjoy them in my landscape with leaves, instead of without.I simply use the piece of bamboo cane to remove the nest, inserting the tip into the structure and twisting gently till all the sticky, web-like bits (and the caterpillars) are on the stick. I deposit the contents on the ground near my shoe, and step on it for good measu

I N A WEEK OR SO I’LL ENJOY THE BORROWED VIEW of several giant old forsythia, left behind from a long-gone farmhouse that stood just down the road. I love seeing them through the naked woods, giant waterfalls of gold, but I don’t grow forsythia in the garden here, as you may recall.

(Note on Gallery: Clicking on a thumbnail gives you a large, higher-quality image.)Winterberry hollies are native to swampy areas from Canada south to Florida, from Wisconsin and Missouri east.  Despite their heritage in wetlands, I grow my plants in normal to dry soil, at the edges of my hilly outer fields. I just don’t have wet lowland to offer on my windy hillside.Though they’ll fruit much better in a moist year than a dry one (as with all fruiting plant

At the time of the transplanting of the young umbrella pine, I had never seen another except in botanical-garden collections; unusual or rare was the word. Now they’re at nurseries, but usually quite small and always quite expensive, and they’re pretty easy to kill, at least at first. But what did I know when I uprooted the tree and had it put in that truck?I was just getting really serious about plants, and was a beginning garden writer, meaning I had the privilege of getting paid to visit gardens and nurseries and interview experts for stories. Those years formed my advanced education in horticulture—and also my downfall in self-control. Everybody showed me or told me about something I simply had to have. Or two or three.An umbrella pine first spoke to me in a come-hither voice at Planting Fields Arboretum in Oyster Bay, Long Island, a place I’d visited a lot as a

Birds have already decimated my shadbushes (Amelanchier species), whose fruits I have also eaten on occasion (not bad). And there’s no competing against the birds and chipmunks for the lowbush blueberries.But with the baneberry (which has creamy April blooms, left) and with shrubby Daphne mezereum (fragrant purple flowers then, too) and some other showy creatures in their second glory right now, the fruit is poisonous to humans. The ba

Unless they are overgrown, lilacs don’t need much pruning (except the “musts” for every woody plant we all agreed recently that we’d keep up with, removing dead, diseased and damaged woody, or any that’s just not well-placed).But by doing a little pruning (read: cutting bouquets of flowers to enjoy) you do the plant a favor, and prevent the ugly aftermath of lilac-blooming season, those dried-up trusses that persist forever, or so it seems.

THE PLANT CATALOGS look delicious, but what plans have you made for where those wishlist items might go, and how many of each do you need to make them really say something in the garden? I love creating mixed plantings of shade treasures–bulbs and perennials, and especially extra-early bloomers–under deciduous trees and shrubs. I call the process “Making Mosaics,” and it’s one of the how-to sidebars in my 2013 book, “The Backyard Parables.” It’s also a video, with photos I’ve taken here at my place.

When I have garden tours, everyone asks what “that silvery-green tree by the vegetable garden” is—even many experts—because you don’t usually see it looking like a tree.And even though I know somebody changed its name, at first I answer, “Salix rosmarinifolia…I mean…” then stop myself, and get it right.The reason you won’t see this looking like a 15-foot-tall, 20-foot wide small tree is that as with other “shrubby” willows, regular rejuvenation pruning is usually practiced.“Will get leggy unless cut back hard periodically” is the kind of advice you’ll find in refer

MAKE ROOM ON THE SHELF—a big, fat space in a prominent spot, since you’ll be reaching for it a lot—and also in your garden. With Mike Dirr’s massive new “Dirr’s Encyclopedia of Trees and Shrubs,” all 3,500 photographs and 3,700 species and cultivars of it, the man we’ve relied on for decades to tell us what’s what in woody plants outdoes even himself. By the time I’d gotten through the “A’s,” I had a list so long of new must-have’s (Abies and Acer, especially–oh, those firs and maples!) that I’d have to rate this book as not just “smart, opinionated, comprehensive, wonderful,” which is what it says in my blurb on the back cover, but “dangerous,” too. So like I said, make room–maybe for the copy that I bought to share with a lucky one of you? The new book came at just the right time for me on two fronts. I manhandled a 1983 edition of Dirr’s thorough-but-not-illustrated “Manual of Woody Landscape Plants” from then until it fell apart, when I replaced it with a 1998 edition, which now is looking far worse for wear, too. There is hardly a workday in all those years when I have not gone to see “what Dirr says” about a tree or shrub I’m growing, thinking of buying, or writing about: How big will it get? Where is it native to? What conditions must I offer it?  All of that is covered in “Dirr’s Encyclopedia of Trees and Shrubs,” but the chance to see shots of the plant–details and often full-grown versions as well–makes all the difference.

I have grown a lot of viburnums over the years, and have pruned them at various times of year for one reason or another. Usually viburnums need relatively little pruning, assuming you planted the right cultivar in the right-sized space (for example, not ‘Mariesii’ among the doublefiles, shown, but ‘Watanabei’ if you only had a smallish area). Even the lightest form of pruning, the removal of spent flowers called deadheading, isn’t needed with most viburnums, since what you want is fruit after the flowers (unlike all that deadheading with lilacs, for instance, to prevent messiness).POOR PLANNING TO BLAMEMost of the pruning I’ve had to do on viburnums was because I didn’t leave enough room for the plant to reach its eventual size, and poor planning (meaning my impatience to have a filled-in garden) caught up with me in time. I have cut several viburnums to the ground or the

TODAY DWARF AND SEMI-DWARF varieties of apples and other fruit trees are the norm, but when the half-dozen or so apple trees that remain from the old, old orchard I garden in were planted, the norm was full-size or standard trees. Their shapes were barely visible when I bought the property, overgrown with a combination of their own unnecessary, thicket-like growth and miles of multiflora roses and grapevines.

Still ahead: Dozens and dozens of shrubby winterberry hollies (Ilex verticillata), which are mostly still all green but covered in berries. They’ll rate a whole post of their own once they’re ready, once they’ve gone golden or tangerine or fire-engine red and dropped their leaves. Stay tuned on that score.So which is it now as you look out your window: What lies ahead? Is it uh-oh, or yippee over there?Categoriestrees & shrubsTagsfall garden

My plant came home with me in the early 1990s from Western Hills Nursery in Northern California, which still sells it today (including by mail, apparently).Much smaller on all fronts than the all-green Kerria japonica, and with single (not the bawdier puffy double) flowers, K.j. ‘Picta’ is an airy thing, perhaps 4 or 5 feet tall. Because it’s a bit of a colonizer, the potential width varies greatly; mine is now 10 feet across. I dig up suckers and share them or move them to another part of the garden, if it gets too wide, and a few times over the years when it was looking thin, I simply cut the whole thing to the g

Various kinds of borers can impact crabapples, not just the apple-bark borer, I know now after reading the fact sheets from various Cooperative Extensions around the country. Unlike the one in the photo up top, with borer entry points at eye level, one of my trees has damage at the base, more like what you’d expect from a vole, but there’s a tell-tale sign, Dennis explained: the presence of frass, or sawdust-like reddish debris that’s a combination of wood particles and insect wastes. Where you once would have seen cambium, you see frass. Sometimes cracks in the bark will also ooze sap.If you have a strong stomach and want to see what I am up against, Clemson University and Colorado State have some lovely photos of borers. I would have taken the shots myself had I been able to locate the hideous creatures, but so far no luck. If you are looking for me tomorrow, I will be out there with pieces of wire probing the tunnel system that was once my tree’s infrastructure, to

Not so many years ago, most nurseries only carried the old-fashioned classic we call Pee Gee, for H. paniculata ‘Grandiflora’ (above), with giant conical trusses of white flowers in July that fade to pink and tan as autumn approaches. Perhaps you have a tree form?  It’s the kind of plant often “inherited” along with older houses, and I love passing big ones at nearby farms and gardens at this time of year.Lately, though, as with so many other plants, there’s a proliferation of available cultivars of panicle hydrangeas, and I have tried many good ones: ‘Kyushu,’ ‘Pink Diamond,’ ‘Unique,’ ‘Limelight’ (an unusual recent color break with greenish flowers), and more that I cannot even bother to r

THEY ARE GARDEN STALWARTS, FEARING NOTHING–not even low single digits and multiple feet of snow. In this old-fashioned Northeastern winter of 2010-11, I’m counting my blessings, and tops on that list: the conifers who live here with me (including the weeping Alaska cedar, Chamaecyparis nootkatensis ‘Pendula,’ above).

(click any green type to link to the profile of that plant)Golden hinoki cypress, Chamaecyparis obtusa ‘Crippsii’Japanese umbrella pine, Sciadopitys verticillataConcolor fir, Abies concolorWeeping Alaska cedar, Chamaecyparis nootkatensis ‘Pendula’Korean fir, Abies koreanaLacebark pine, Pinus bungeanaFavorite Coniferous ShrubsRussian arborvitae, Microbiota decussataGolden spreading yew, Taxus baccata ‘Repandens Aurea’Dwarf white pine,Pinus strobus ‘Nana’Conifer SlideshowIf you missed it earlier this year, tour the above favorites and more in my slideshow of favorites conifers.Categoriesconifers for beginners trees & shrubs

S HRUBS ARE THE PEOPLE-SIZED PART OF THE LANDSCAPE, the middle layer that you cannot make a garden without. If you go and skip the shrubs, the transition from tree to perennial is just too drastic, don’t you think? I tried to pick one kind to profile today—lilacs, perhaps, or twig dogwoods (both in the photo above and both treating me to a show at the moment) or maybe a viburnum?—but I failed to single anybody out.

100 Great Plants: From the English newspaper The Telegraph, a list of 100 great garden plants. (An aside: Why don’t our newspapers have garden sections like this one?)The Ambergate Lists: From Ambergate Gardens, Mike and Jean Heger’s nursery in Minnesota, a series of great lists covering topics from plants for deep shade to plants that don’t require frequent division.Vinnie Simeone’s Lists: Vinnie manages historic Planting Fields Arboretum on Long Island, my old stomping grounds, and has taught me many things. His personal website includes links up top to lists as desired as deer-resistant plants and plants for