Slitting bark of rootstock


How to “Make” a New Tree

Visitors to my garden this time of year are often astonished to see me lopping the tops off some of my trees. No, I’m not the Henry the Eighth of horticulture, chopping the head off any tree that no longer meets my fancy. Okay, I AM actually lopping the head off any tree that doesn’t meet my fancy.

I part ways with Ol’ Henry, though, because, first, lopping the head off a tree doesn’t kill it and, second, I graft on a new head. (Something Henry could not do.) A few years after this seemingly brutal operation, the tree looks as chipper as ever. And it has a head that I like better — or else off it comes again.Inserting scions for bark graft

I do this type of grafting, called topworking, mostly on my pear trees, but it could equally be applied to many other kinds of fruit or ornamental trees. Read more


Winter Games

Trying to identify leafless trees this time of year is a nice game I like to play alone or with a companion as we walk about enjoying the brisk winter air. I like this game because it forces me to take a close look at the more subtle details of plants, in so doing giving increasing appreciation of the plants even now when they are stripped of leaves and flowers.

Of course, this is hardly a game with some trees. Everyone recognizes paper birch by its peeling, white bark. Paper birch bark(Watch out, though, grey birch has similar bark.) Catalpa tree is quickly identified by its long, brown pods. And pin oak by its growth habit, its lower branches drooping downward, its mid-level branches spreading out horizontally, and its upper branches reaching for the sky.Pin oak form

Most deciduous trees don’t have such obvious signatures this time of year. Then, what’s needed is an observant eye and a good resource to describe trees in words and pictures. Particularly helpful are those books that take you through a logical sequence of steps in identification. Fruit Key & Twig Key to Trees and Shrubs, by William Harlow is one such reference. Or the web, of course.

Buds, Twigs, and Fruit

One of the first features I look for when I’m confronted with an unknown, leafless tree is the arrangement of the buds on the young twigs. Are the buds “opposite” (in pairs, one bud right across another along each twig), or “alternate” (single and separated from each other along the length of stem)?

It turns out that most deciduous trees around here have alternate buds. Conversely, most shrubs have opposite buds. So if I see opposite buds on a tree, the choice immediately is narrowed to MADCapHorse. No, that’s not a typo; it’s an acronym for Maple, Ash, Dogwood, Caprifoliacae (honeysuckles and viburnums, for example), and Horsechestnut, all trees with opposite buds and leaves. That still leaves the challenge of honing down the choices of species within one of those genera or family groupings.

Other features further narrow the choices within opposite- or alternate-leaved trees. The shape of the buds can be telling. For example, flowering dogwoods have flower buds that look like little buttons capping short stalks. Cornus mas budsPawpaw’s buds are rusty brown, and fuzzy like velour. Also telling are twig color. Pawpaw budsPurple twigs covered with a cloudy coating identify a tree as boxelder.Boxelder stem

Another feature I look for, hopefully before it finds me, is thorns. If present, the tree is most likely black locust, honeylocust (watch out again, though, because most cultivated forms of honeylocust are thornless), hawthorn, or wild plum. Black locust has short thorns, honeylocust has long thorns, often branching, and plum’s thorns are, in fact, short, sharp branches with little buds along their length. Not native here in the Hudson Valley, but occasionally planted — by me, for example — is osage orange, with the most vicious thorns of all.

Fruits are another guide. Prickly gumballs hang almost through winter from sweetgum trees.

Sweetgum leaves & gumballs

Magnolias still have their fruits, which look like little pineapples with red seeds popping out. And it’s within the rules of the game to look on the ground for help in naming a tree. There, you’ll still find some nuts of the shagbark hickory, identified also by its shaggy bark, and oak acorns. Then the game gets interesting, as I try to narrow down which of the 400 species (200 native to North America) dropped that acorn. Here’s an excellent website to hold my hand along this path. Knowing most of the native and frequently planted species lets me narrow those choices from the get go.

No obvious fruits or thorns, so still at a loss for a tree’s identity? The taste of a twig sometimes is the giveaway. Black cherry tastes like bitter almond, and yellow and river birch taste like wintergreen. Paper birch twigs are tasteless. Slippery elm twigs become mucilaginous when chewed.

My Favorite (Dog-free) Bark

My favorite winter tree feature, for identification and for beauty, is bark. And some are as obvious as paper birch. Shagbark hickory is as easy to pick out from a forest of trees as is paper birch. Shagbark hickory

Many others are similarly obvious. American hornbeam has smooth, blue-grey bark with ripples like muscle, which gives the tree one of its common names, muscle wood.American hornbeam bark Flowering dogwood’s bark is made up of small, squarish blocks. American persimmon has similar looking bark, except the blocks are larger and more raised, resembling alligator skin (but not frightening). Persimmon barkContinuing in the zoological vein is beech, whose smooth, brawny trunk and limbs look like they could belong to a mythological elephant.

Many maple species can be honed down by their distinctive bark. A bark that makes the trunk look like it’s been wrapped in buffed copper that curls away in fine curls is just like hanging a sign on the plant that says “paperbark maple.” Paperbark maple barkSugar maple bark has grayish, vertical strips that, with age, becomes more furrowed and the strips start to detach. Large limbs attach to the trunk with distinctive furls.

My favorite of all tree barks belongs to hackberry. I planted a couple of these trees just so I could enjoy their bark in winter. The smooth background of the gray bark is broken up by corky warts and ridges that play with shadow and light in a way that evokes the crisp, achromatic photographs of craters on the lunar landscape.Hackberry bark

All this only scratches the surface of details that we tend to overlook in spring, summer, and fall. Some of these details are interesting, some have a subtle beauty, and some are useful only for identification.

As far as the identification game, there is one more very useful identifier. Deciduous trees are supposed to be leafless now. It’s not cheating to cast your eyes down for a leaf that may have dropped from the tree in question. A few leaves may even hang on into winter. They will be dead, dry, and twisted, but often still “readable.”

Not only that, but oaks and beeches are so reluctant to lose their lower leaves that you can spot these species even at some distance by their skirt of retained, dry leaves.

(An additional hardcopy resource for tree identification is the The Sibley Field Guide to Trees by David Allen Sibley.)


Not a Gardener? I’m Honored

Perhaps some one or two of you readers of this blog might be just that — readers, not gardeners. An occasional reader has admitted this to me. Although I feel honored to be read by any non-gardener, herein is my effort to get humus under the fingernails of you gardening equivalents of “Monday night quarterbacks.” 

I reckon that now, when plants are lush and have already offered or are hinting at future offerings of fruits, vegetables, and flowers, is the easiest time of year to spur your enthusiasm. Also, it’s still not too late to start a garden. I started my first garden -– in Wisconsin -– on August 1st and reaped tomatoes, beans, and other vegetables!Garden entrance

I could begin by going on and on about the favorable economics of gardening, wowing you with statistics about how much cheaper it is to grow broccoli, peaches, and tomatoes than it is to purchase these items at the grocer’s or the florist. Research back in 2014 found that, on average, a home vegetable garden yields $832 worth of fruits and vegetables beyond the cost of $285 (both figures in today’s dollars) worth of materials and supplies. Saving seed, substituting home-made compost for some or all fertilizer needs, and drip irrigation are among ways to lower costs of gardening. Good planning and good soil management could increase those returns.

So especially with these days of inflated prices, economics can be a very convincing argument for gardening, surely if you plan to eat a lot of vegetables or want flowers spilling out all over the place indoors and out — not such a bad idea at that, either of them. (Probably with flowers; I didn’t come across any figures for growing versus buying flowers.)

For the Best . . .

Quality is where the rift between buying and growing widens, in favor of growing. It’s impossible to buy (except pick-your-own) peas, lettuce, peaches, tomatoes, and many other vegetables and fruits that come even close to being as good-tasting as those you can grow. The peas picked here at the farmden today were perfectly ripe and required about six seconds of shipping (with little bruising) from plant to mouth. In a couple of days, I’ll be picking gooseberries: a dozen different varieties, none of which could I buy off the grocer’s shelf.

Early summer fruits

Early summer fruits

When it comes to cut flowers, I’ll admit to being on shakier ground promoting home-grown over bought. Just look at a bunch of commercial roses. Each flower is perfection, with not a scar from pests.

But could such perfection be turned around and looked upon as a shortcoming? Aren’t “real” flowers attacked by bugs and diseases, and do “real” flowers all open perfectly? As long as imperfections are not carried too far, I find them acceptable, perhaps even desirable. Commercial cut flowers are available out of season, but this shortcoming of home grown could be remedied with a home greenhouse.

Vase of homegrown roses

Vase of homegrown roses

A Great Coach and Teacher

How about next comparing the physical and emotional rewards of digging the soil, bending to weed, and pitching forkfuls of manure with jogging in place on a treadmill or doing pushups? Just as Thoreau’s wood heated him twice, first when he cut it and then when he burned it, so the garden provides health twice. Even before you reap your first harvest of healthful fruits, vegetables, and herbs, you benefit from the physical exercise associated with cultivating plants.Hauling mulch

Exercise experts have even quantified some of the health benefits of gardening. A study from the University of Minnesota, for example, reported that individuals who spent 45 minutes per day gardening had one-third fewer heart attacks than those who were sedentary. Another study found that physical activity, particularly gardening, lowered risk of dementia by 36 percent.

Even breathing fresh air when gardening has its benefits. Well, not just air; the soil bacterium Mycobacterium vaccae was found to alleviate depression by activating seratonin releasing neurons in the brain.

But really, who needs studies to generally know all this? 

And what of the less tangible rewards of gardening? A hundred years ago, Charles Dudley Warner wrote in My Summer in a Garden how gardening provides “exercise which soothes the spirit and develops the deltoid muscles.”

Deb rakes mown hay.

Rei-King by Deb as Sammy looks on.

Rudyard Kipling evidently considered gardening a general cure-all when he wrote

The cure for this ill is not to sit still
Or frowst with a book by the fire;
But to take a large hoe and shovel also, 
And dig till you gently perspire.

Finally, the garden is a great teacher. Close observation of plants and their environment can teach chemistry, botany, entomology, and pathology. Gregor Mendel formulated the basic laws of genetics in his monastery garden. The garden teaches more than just science, though. Gardening also teaches “patience and philosophy and the higher virtues — hope deferred, and expectations blighted, leading directly to resignation, and sometimes to alienation. The garden thus becomes a moral agent, a test of character, as it was in the beginning” (again quoting from My Summer in a Garden).

Like any good teacher, the garden rewards. Such rewards may be deferred, but they are sure to come, doled out piecemeal after just days (when you plant radishes), after weeks (when you plant marigolds), or after years (when you plant a maple tree).

Hakurei turnips 38 days after planting

Hakurei turnips 38 days after planting

Chestnut, 19 years after planting

Chestnut, 19 years after planting


Dinosaurs and Snake Eggs, and More

Most benefits of compost are well-known: it takes out your “garbage,” it fertilizes your plants, it’s teeming with beneficial microorganisms, yadda, yadda, yadda. One too often overlooked plus for compost is the thrill of discovery, discovery of things other than compost in the pile.

Discovery might range from the mundane to the sublime. Among the mundane discoveries is that glint of a lost kitchen fork as it emerges from within the chocolatey pile. Same for the favorite vegetable peeler or the lost stainless steel coffee strainer.

More towards the sublime end of the spectrum would be the dinosaur that surfaced as I was turning a pile a few years ago. A dinosaur! Yes, a small, plastic one that got there from who knows where. 

More seriously sublime was the clutch of about three dozen soft, white eggs about the size of quail eggs that came into view as my pitchfork lifted a clump of compost for turning into the adjacent compost bin. Turns out they were snake eggs, those of a black rat snake. Adult black rat snakeSome snakes give birth to live young, ready to crawl; black rat snakes lay eggs.

I put a few of those snake eggs into a terrarium along with some compost to see if they would hatch. For the uninitiated (me), it’s an eerie sight to see such a traditionally maligned creature emerge from such a welcome, traditional symbol of springtime rebirth. Baby black rat snakes are not black. Instead, bands of dark and light gray run across their backs.Baby black rat snake

Another time, while turning my compost pile, I accidentally disturbed a mating pair of black rat snakes in flagrante delicto.

Ducks and Grubs, and More

White grubs occasionally turn up in my pile, but a couple of days ago, one of my piles was home to at least two dozen of the C-shaped, creamy white grubs resting within. Grubs in compostOn the chance that they were grubs of Japanese beetles, I started picking them out and yelling “Quack, quack.” No, I hadn’t lost my mind; I was calling the ducks over for a treat of beetle grubs. They dashed for each tossed grub as it hit the ground.

And then a mouse, disturbed in my compost turning, made a dash out of the bin and across the lawn. A mouse in a compost bin is not that surprising, although the construction of my bins and my two dogs are pretty good at keeping mice at bay. (I make efforts to limit mouse populations because they can spread diseases such as hantavirus, salmonella, and lymphocytic choriomeningitis.)

One of the ducks took a break from grub hunting to grab the mouse which, judging from the chase the other ducks gave the lucky duck, is more of a gourmet duck food than even the grubs. Soon only the mouse’s tail was hanging out the duck’s beak, and then the mouse was down the gullet. Here’s a video I took of the Duck eating mouse

But Does Compost Really Need Turning?

You might wonder: What’s with all this compost turning? Each of my compost bins holds a half to three-quarters of a ton of compost, each pile gets turned once, and I have a number of piles. Is it worth all that  work?

Turning a compost pile lets me see how the process is chugging along. I keep a record of when a pile was built, and then months later, when it’s turned, how far along it is to being ready to use. After I turn a pile a make a guesstimate of percent decomposition, which is accurate enough for me to know about when it will be ready for spreading.

Turning a pile also lets me get a look at the compost-to-be and then to make any adjustments that might be necessary. I’ll lightly hose down every few inches of turned material, enough to make the ingredients glisten. Anything looking exceptionally dry gets extra water. Occasionally, part of the pile is too wet. I fluff it up as I flip it over into the adjacent bin. Parts of the pile might be compressed into a dense mat. Throwing it into the adjacent bin might be enough to loosen it up; if not, I pick at it with the tines of the pitchfork.Compost pile turned

Turning the pile also mixes up the ingredients more than when the pile was built. Each part of the pile, then, gets new neighbors in the form of new ingredients and new microorganisms.

Turning a compost pile is not absolutely necessary, although it’s probably best to leave a bin intact longer if the pile isn’t turned. On the other hand, I find turning a compost pile not only interesting, but also enjoyable and nice exercise.


(The following is adapted from my book, A Northeast Gardener’s Year.)

It’s Not All in a Name

With only a name to go on, which tomato would you choose to grow: Supersonic or Oxheart? If the name Oxheart seems a bit too gruesome, make the choice between Supersonic and Ponderosa. My guess is that most gardeners would choose Oxheart or Ponderosa for a tomato, Supersonic for an airline. What compels a contemporary plant breeder to give a tomato a name like Supersonic?
Heirloom tomatoes
Many old-time names of vegetables – Oxheart and Ponderosa tomatoes are examples — were a lot more appealing than some of the newer names. It could even be that a good name is part of the reason a vegetable of yore still appears in today’s catalogues amongst all the new hybrids.

What’s the Difference?

These names I am talking about are “cultivar” names, or what were once called “variety” names. Problem is that the word “variety” can have two meanings with respect to plants, referring either to a horticultural variety or a botanical variety. To avoid confusion between the two meanings, the word “cultivar” was written into the International Code of Nomenclature of Cultivated Plants in 1958.

A botanical variety is a naturally occurring population of plants one subdivision below the species level. A cultivar is a cultivated variety of plant. All cabbages are Brassica oleraceae var. capitata; all broccolis are Brassica oleraceae var. italica. Early Jersey Wakefield is one cultivated variety, or cultivar, of cabbage, designated, in full, as Brassica oleraceae var. capitata cv. Early Jersey Wakefield. No need to rattle off this whole name when you’re looking for a pack of this seed. Just ask for “Early Jersey Wakefield cabbage.”
Early Jersey Wakefield cabbage

Why That Name?

Many old-time cultivars have interesting names, interesting sometimes for no other reason than because the rationale behind the name is not immediately obvious. As I thumb through a catalogue of vegetable cultivars, I can’t help but wonder why anyone would name a parsnip cultivar The Student. The same goes for Old Bloody Butcher corn and the Missing Link apple. Such names surely were not chosen as marketing ploys. In the case of the string bean cultivar Lazy Wife, the rationale behind the (sexist) name is not at all obscure (old-fashioned string beans had to be de-stringed). Compare such clever names with those of some of today’s cultivars — Superhybrid eggplant, Green Duke broccoli, or Bounty green bean.

Some of the old cultivar names have a nice ring to them. Who can resist growing a corn called Country Gentleman, or a bean called Red Valentine? Such names are more appealing than cutesy names like Kandy Korn corn or Tasty Hybrid pepper. Well, at least the pepper is Tasty Hybrid, rather than Tastee Hybrid.

Popcorn: Old Dutch Buttered and Pink Pearl

Popcorn: Old Dutch Buttered and Pink Pearl

Which cultivar name sounds more appealing to you: Red-Cored Chantenay carrot or Six-Pack carrot? Calabrese broccoli or Packman (or is it Pac-Man?) broccoli?

Some of the old names might have had appeal in their day, but just would not fly today. With metropolitan New York City looming closer than ever, Hackensack melon can’t evoke the bucolic tang it did back in 1929. And I doubt that any plant breeder today would name a beet cultivar Detroit Dark Red. Nothing against Detroit, but it is a name better applied to an automobile or a kind of music than to a beet cultivar.

Calm Down

Before you lovers of Supersonic, Jetstar, and Ultra-Boy tomatoes get your hackles up, remember that I’m not knocking the quality of these varieties — whoops, cultivars — but only their names.

In fact, appealing names often were assigned to cultivars of dubious merit in the past. The name Sops of Wine makes my mouth water more than did the actual apple. The same goes for Maiden Blush apple – beautiful name (and beautiful fruit), but mediocre eating quality. On the other hand, how about the luscious, relatively modern apple with the vapid name of Jonagold. The appellation was derived simply by combining the names of its parents, Jonathan and Golden Delicious.

As you peruse seed racks, garden catalogues, and websites in the coming weeks, think about what makes you choose one cultivar over another. By the way, for flavor, I highly recommend Early Jersey Wakefield cabbage.

Get Ready For Spring, With a Webinar

I will be hosting a WEEDLESS GARDENING webinar on Monday, February 22nd for $35.  It will run from 7-8:30 pm EST and there will be plenty of opportunity to ask questions. For details, go to Or trust me, and go right to registration (required) at .


Roots Do It

Some people get their kicks from hang gliding; some from racing cars. Call me mundane, but I get a similar thrill, minus the fear, from seeing cuttings of some new varieties of figs that I am propagating take root. The cool thing about hang gliding, racing cars, and rooting cuttings is also the sense of satisfaction you get from doing it well.

The current batch of cuttings provides special satisfaction because the method I used, gleaned from the web (see, for instance, what turns up with a search for “fig pops”), permit me to check and observe progress frequently. Usually, I stick a cutting into a rooting mix and learn that rooting has taken place by the resistance of the stick to an upward tug or by roots escaping through the drainage hole in the bottom of the pot. With fig pops, I get to see each cuttings wiry, white roots wending their way through the rooting mix soon after they first start to develop. Fig pops are also a way to root lots of cuttings in a small space.
A fig pop
The current figs are rooting in 3” by 8” clear, thin plastic bags filled with my usual 1:1 mix of moist peat moss and perlite.  I pushed the cuttings, fig “sticks” of last year’s growth 1/4 to 1/2 inch thick, into the mix almost to the bottom, then sealed the top closed with a twist-tie. One cutting per bag. Roots need to breathe, so I poked each bag full of holes with a toothpick. That’s it, except when the bags seemed too dry I stood them in a pan with a couple of inches of water for awhile.

(Dipping the cuttings in a commercially available rooting hormone would probably improve rooting, but I don’t use them. To me, the health precautions needed when dealing with them takes the fun out of gardening.)

All that, and time, would have been enough. But to speed things up, I moved the cuttings to a place where they’d get some warmth on their bottoms. That could have been atop a refrigerator, above, but not on a radiator, or, in the case of my cuttings, on a seedling heating mat.
Fig pops
Fig pops together in tubNo light is needed until cuttings start to leaf out. Which is an exciting moment, because roots might — or might not — begin to show about then. All that’s needed is to lift a fig pop and take a look. Some of mine showed roots after only 3 weeks! But it’s good to let them get well rooted before disturbing them.
Rooted figs
When the time came to move a well rooted cutting, I sliced the plastic on the bottom and up along one side of its bag and put the whole root ball in a bona fide pot, filling in with bona fide potting soil around it.

That’s it. Growth will pick up with increasing warmth and sunlight. And then fruit, which could arrive on the branches even this growing season. Figs are admittedly easy to root by any method. As with any cutting, an important ingredient for success is patience.

Graft (Nonpolitical) is Good

Moving on, next week, to another perennial source of excitement here in the garden: grafting. I do this every year about now? Why every year? Because I’m always getting scions (1-year-old stems for grafting) of new varieties of fruits, mostly pears, to try out or to replace existing varieties. Or I might want another tree or two of a variety particularly worth growing here.

If I’m replacing an existing variety, I do a Henry the Eighth on the tree, lopping off its head, low, to graft a new variety onto the remaining stump. With the established root system underfoot, these grafts grow very vigorously and bear relatively quickly — sometimes the year after grafting. 

Alternatively, I make a whole new tree by grafting a scion onto a one-year-old rootstock that I purchase or grow. These small trees will take longer to come into bearing, how long depending on the kind and variety of fruit, and the rootstock.

Stump of older graft

Stump of older graft

A rootstock, whether the remaining stump of a lopped back mature tree or a pencil-thick young plant, has to be closely related to the scion that will be grafted atop it for the graft to be successful. Rootstock and scion in the same genus generally do well together, so pear on pear, apple on apple, even peach on plum are compatible. Occasionally, plants in the same family but different genus, such as pear and quince, also join well.

Whip graft close up

Whip graft

One way to create a rootstock would be to just plant a seed, giving rise to the appropriately named “seedling” rootstock. A seedling rootstock’s main claims to fame might be its general toughness and its genetic diversity from other seedlings. That genetic diversity is a downside if you want to plant an orchard of uniform trees; it’s an asset if you don’t want some pest all of a sudden wiping out all your plants with genetically the same rootstocks.

Rootstocks have been selected or bred that impart special qualities to a tree, and these rootstocks are propagated not by seed, but by any one of a number of methods of cloning (cuttings, tissue culture, mound layering, etc). Most dramatic might be the effect on plant size. The Malling 27 variety of apple rootstock, for instance results in a tree that matures at about 7 feet high. As with many dwarfing rootstocks, the tree also yields its first harvest quickly with, although less fruit per tree than a larger tree, more fruit per sure foot of space. And you can plant many dwarf trees in the same space as one full-size tree.
Apple rootstocks
Dwarf trees also have the advantage that pruning, harvesting, and other needs can be met with your feet planted on terra firma. Any disadvantages? Yes: more finicky about growing conditions, much shorter lifespan, and often needing staking throughout their lives. But there are many rootstocks from which to choose, especially with apples and pears, so you can choose what suits you from a fully dwarfing tree on up to full-size tree. A rootstock might also be selected for its tolerance for certain soil conditions, hardiness, and other environmental hazards.

Most important: The rootstock, for all its effects, has little or no influence on the flavor of fruit grafted upon it.

I’ll be grafting next week. Stay tuned for the 2 or 3 easy grafts I use to make trees.


More Than Just Pignolis and Piñons

Pine trees first appeared on earth 170 million years ago amidst lush, steaming forests of tree ferns and the footprints of dinosaurs. In time, human footsteps replaced those of the dinosaurs. Pines and humans have been intimately associated ever since. The trees have been worshipped; the cones have represented symbols of fertility; the pitch has sealed ship hulls; and the wood has been used for construction and for paper.

Korean pine

Korean pine

Throughout this long association, seeds of certain pines have been part of our diets. The flavorful seeds of native pines have a long history of use as “nutmeat” by the people of Siberia, the Himalayas, southern Europe, and the American Southwest. Look into almost any Italian grocery store in America, and you’ll find tempting cookies studded with pignolis, which are seeds of the Italian Stone pine (Pinus pinea). Pine nuts are the nut for pesto and dolmas. And from the American Southwest come seeds of the piñon pine. 

Although pine nuts usually are associated with the dry, mild climates of Southern Europe, the American Southwest, and northern Mexico, there are pine species that will produce edible nuts outside of their native range — even in the humid, often frigid, climate of my farmden. Nut-producing pines run the gamut from scrubby shrubs to majestic trees, some with needles that are soft and misty, others with needles that are dark and somber.  

Korean pine (P. koraensis), Swiss Stone pine (P. cembra), and Siberian pine (P. sibirico) are the three most reliable nut-producers for cold climates. All are hardy to at least minus twenty-five degrees Fahrenheit. The Korean pine is the most commercial of the three, producing 5/8-inch-long seeds that are exported from China. The tree itself will eventually tower to a soft, dark-green pyramid of 150 feet. 

Swiss Stone pine finds a congenial home in the small garden, eventually reaching 50 feet or more, but very slow-growing. Native to central European Alps, this pine has dark, almost blackish-green, needles that, with the short branches, seem to hug the trunk. The Siberian pine is similar, except faster growing.  

Swiss Stone Pine

Swiss Stone Pine

Many other pine species potentially could produce pine nuts outside their native range, though their adaptability to very cold winter climates has not been not thoroughly tested. The closely related Colorado Pinyon (P. edulis) and Singleleaf Pinyon (P. monophylla) pines are bushy trees that become flat-topped with age. I planted a Singleleaf pine years ago; it’s annual growth was measured in inches. With the slow growth and lack of nuts, I eventually tired of it.

One of my favorites, unfortunately not hardy below 10°F, is the Digger (P. sabiniana). I saw many of these trees years ago as I was driving west down from the Sierra Nevada mountains; I came screeching to a stop when I spotted one of the large cones lying near the road. Passing motorists might have taken me for a lunatic as I tried to smash open the coneby smashing it repeatedly on the guardrail. This species bears lima bean sized pine nuts.

Some other pine species producing edible, albeit small seeds, are Himalayan pine (P. wallachiana), Limber pine (P. flexilis), Jeffrey’s pine (P. jeffreyi), and Japanese Dwarf Stone pine (P. pumila).

My Personal Pinetum

I’ve entered the world of nut pines with some plants here on the farmden. I began, of course, with Korean pine, but can’t claim great success. My largest tree, now about 35 feet high, has occasionally produced a cone near its summit. Perhaps some squirrels got them; I didn’t. The tree is a dead ringer for our native white pine (Pinus strobus); the most direct way to differentiate the two would be from the Korean pines cones, which are about half the length (about 4 inches) of white pine’s cones.

My older Korean pine

My older Korean pine

Just this year I purchased two more Korean pine seedlings. They’re each only a few inches high now, and I hope they bear like a friend’s Korean pine, which was loaded with cones when a mere 6 feet in height.

My younger Korean pine

My younger Korean pine

I’ve also planted a lacebark pine (P. bungeana). Besides offering pine nuts, the bark of this pine flakes off to yield pleasing patterns similar to that of sycamore. Neither nuts nor flaking bark here yet, though.

Lacebark pine

Lacebark pine

 Care and Feeding

 Nut pines, in common with most other pines, require little care. They are frugal plants, getting by with minimum water and fertility. They do require full sun and well-drained soil, though. Think of those dry, rocky slopes to which pines cling in the wild.

Two seasons are usually required for a female pine cone to produce ripe seeds. The cone is a primitive type of flower constructed of a tight cluster of either male or female reproductive cells at the bases of scales which spiral around a short axis. In the spring gusts of wind shake loose pollen from the male cones, which are catkin-like clusters located mostly at the tips of the trees’ lower branches.  Yellow clouds of pollen waft upwards to the female cones, most of which are high in the trees. Fertilization, the actual union of the male and female reproductive cells, takes place during the spring following pollination, within the tightly closed, green female cone. Seeds ripen at the end of the second season.

How a pine disperses its ripe seeds can mean the difference between getting pine nuts into your pesto or losing them to foraging squirrels or in the needles beneath the trees. With some pines, ripe seeds drop from open cones that remain attached to the trees. Other pines will not open their cones to release their seeds except with the stimulus of heat or the blow of a hammer. Such a mechanism, making it possible to beat the squirrels to the bounty, exists for the Swiss stone pine and the Siberian pine. The Swiss Stone pine clings to its neat little seed packages until the third spring from flowering.

It’s almost impossible to suggest an expected yield of nuts from a single tree. The trees are rarely grown in plantations. Most nuts are harvested from more or less wild trees, rather than from trees growing under uniform orchard conditions. And even then, yields are variable and erratic.

Lack of precocity or erratic nut production shouldn’t be a deterrent to planting a nut-bearing pine. What these pines lack in instant gratification, they furnish in “piney” fragrance,  longevity, and for the beauty and character they bring to a landscape.


(The following is excerpted from The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden, available here.)

Write the Name Right!

With little pressing, gardenwise, this time of year, why not muse about plant names — their common names and their sometimes intimidating-looking botanical names? Take the tree commonly named dawn redwood for example. ”Dawn redwood” admittedly reads more easily than this tree’s botanical name, Metasequoia glyptostroboides.

Wait! don’t stop reading! Instead, speak the Latin name aloud slowly: me-ta-see-KYOY-a GLYP-to-stro-boy-dees. It’s delightful, tonal poetry vocalized by a smooth dance of the lips, the tongue, and the upper pallete. 
dawn redwood
Sensual pleasure aside, botanical names have a practical side. That woolly-leaved plant that sends up a candelabra of creamy yellow flowers each summer has a hundred or so common names. I call it mullein but other names include Aaron’s rod, Adam’s flannel, bullock’s lungwort, and velvet plant. This plant has only one botanical name, though, Verbascum thapsus. 
Each plant gets only one botanical name, and that name is recognized worldwide. A botanical name has two parts, both based on Latin. The first word in the binomial is the genus; each genus is subdivided into one or more species, the second word of the binomial. This system of plant classification was originally set forth in Species Plantarum, a book written in 1753 by Carl von Linne (usually known by the latinized form of his name, Linnaeus.)

I have a pet peeve about botanical names that finds root in a challenge issued way back in high school English class. Mr. Mehegan gave us detailed information on the correct way to list bibliographic references at the ends of our term papers: punctuation, underlining, capitalization, ordering. Then he predicted (correctly) that no one would list all their references exactly right. Now it irks me when rules are not followed in writing plant names.

Rules for plant nomenclature are simpler than Mr. Mehegan’s rules for referencing. Genus and the species names are always underlined or italicized. Genus is always capitalized; species is not, unless it commemorates a person. A species is never written by itself; if the genus is obvious, it may precede the species in abbreviated form.

The Name is Loaded with Information

With correct botanical information under my belt, if I want a packet of marigold seeds, I could ask for Tagetes minuta whether I am in Andorra or Zanzibar.Marigolds In the case of plants like petunia, chrysanthemum, rhododendron, and fuchsia, at least part of the botanical name is the same as the common name in English. In some cases, using the botanical name might be the only way I could be assured of getting the plant I really want. If I wanted to plant bluebells, Hyacinthoides, and searched and asked for it by its common name, I could end with plants in the Mertensia, Muscari, Campanula, or Eustoma genus.

When I’ve planted lilies, I didn’t want to pick from a grab bag of about 80 different species of Lilium; I wanted to plant—and did plant—the sweetly fragrant Lilium candidum (which actually is the only lily with the common name Madonna Lily). I also wasn’t interested at that time in planting daylily (Hemerocallis spp.) or lily of the valley (Convallaria majalis), neither of which are true lilies. Neither is even in the Lily Family, let alone the Lilium genus!
A botanical name can tell a story about a plant: its discovery, its origin, its form. Adalbert Emil Redcliffe Le Tanneux von Saint Paul-Illaire discovered what became known as African violet growing amongst the lush vegetation in the mountain jungles of East Africa; in his honor the plant was given the botanical moniker Saintpaulia ionantha. Juniperus virginiana is a juniper native to eastern North America; Juniperus chinensis hails from China. Tulip tree, Liriodendron tulipfera, has a particularly descriptive name. Liriodendron was the ancient name for this plant, meaning “lily tree.” And tulipfera means “tulip bearing.” Tulip tree’s flowers do, indeed, resemble tulips, as long as you don’t look too closely. Tulip is a member of the Lily family. Tulip tree is in the Magnolia family.

African violet

African violet

Family Matters

Botanical names can tell about plant relationships. The apparent similarity between peaches, plums, and apricots is confirmed in the similarity of their names, Prunus persica, Prunus domestica, and Prunus armeniaca, respectively.

Knowing kinship can help decide what grafts might be successful. Grafts between the same genus and species almost always spell success. Success is even possible between different species of the same genus, which is why I once grafted a couple of branches from my sweet cherry tree (Prunus avium) onto my tart cherry tree (Prunus cerasus). The sweet cherry didn’t bear reliably enough to warrant living here as a whole tree. Emulating George Washington, I chopped the (sweet) cherry tree down following a successful graft.

In some cases, a species might be subdivided into botanical varieties. For instance, cabbage and its close relatives all are Brassica oleracea. But cabbage itself is the botanical variety capitata (meaning head), Brussels sprouts are gemmifera (little gems), broccoli is botrytis (cluster-like), and kale is acephala (without a head). The correct way to write broccoli is Brassica oleracea var. capitata.

If you’re put off by botanical names for plants, take heart because the situation used to be more awkward. Before the days of Linneaus, baby’s-breath was the Latin mouthful Lychnis alpina linifolia multiflora perampla radice. Catnip was known as Nepeta floribus interrupte spicatis pedunculatis. (Both are mellifluous but too long for a name.) Thanks to Linneaus that the scientific names of these two plants now are the manageable and descriptive Gypsophila elegans to Nepeta cataria, respectively.
Cat and catnip

Rosemary Tips

Secrets to Survival

I’ve killed plenty of rosemary plants over the years, typically in late winter. At least that’s when I’d discover that they were dead. Casually brushing against the plant would bring dried leaves raining to the floor.
Potted rosemary tree in winter
Problem is that rosemary has naturally stiff leaves. They don’t wilt to broadcast that the plant is thirsty. And then it’s too late; the plant tells you it’s dead as it’s leaves flicker down.

Perhaps like you, I knew that rosemary is native to the Mediterranean region. The picture in my mind is of the plants thriving on a sun-drenched, dry, rocky hillside in poor soil. True enough, except below ground the roots are reaching deep or wide for water. Which my potted plants can’t do.

Following this latter realization — duh! — I haven’t lost a rosemary plant in years. The secret to keeping a potted rosemary plant happy is to keep it well watered, never letting the potting mix dry out. If in doubt, water.

Rosemary roots also need to breathe, and the way that is assured is by adding plenty of perlite to the potting mix. My mix is 1/4 by volume each of perlite, garden soil, compost, and peat moss. The latter two ingredients help retain moisture while, at the same time, provide for aeration.

Making a Rosemary Tree

I mentioned last week that I grow my rosemary plants as miniature trees, a form also known as “standards.” Here’s how I make mine.

(“Standard” does seem like an odd word to describe such a plant until you realize that the “stand” in “standard” does indeed mean just that. “Standard” comes from the Old English words standan, meaning to stand, rather than flop around, and ord, meaning a place. Further muddying the horticultural waters, in fruit growing a “standard” is a full size tree, as opposed to a dwarf tree.)

The easiest way to set a rosemary plant on the road to standard-dom is to begin with a small plant. Rosemary comes in upright or creeping varieties. Upright varieties, such as Majorca Pink and Salem, are naturally inclined to “stand,” but creeping varieties are also easily coaxed in this direction.

Single out a vigorous and upright growing stem as the standard’s future trunk. In the case of a creeping variety, just select any healthy stem and stake it upright to a dowel or thin shoot of bamboo. Shorten all side shoots to direct the plant’s energy into that trunk-to-be.
First 4 steps in training rosemary standard
The goal, in the weeks ahead, is to promote elongation and thickening of the trunk-to-be. To that end, keep cutting away any new stems sprouting from the base of the plant. Keep pinching back to just a few leaves any side shoots. Doing so keeps them subordinate but lets them help thicken the trunk.

Once the trunk reaches full height, goals change: time to stop growth and create a bushy head. But how high is “full height?” It’s all for show, and what looks good depends on how big a head you are going to give the plant and how big a pot the plant will eventually call home. Generally, a head two to three times the height and just slightly more than the width of the pot looks good. Stop growth at the desired height by pinching out the tip of the trunk, a simple operation that awakens growth of buds down along the trunk.
Second four steps in training rosemary tree
Create the bushy head by repeatedly pinching — and thus inducing more branching — all growth that sprouts from the top few inches of the trunk. Now define that head more clearly by completely removing all stems and leaves further down the trunk.

All these prunings need not be wasted, of course. They could be used as flavoring or as cuttings to make yet more plants.

(Creating standards and other methods of pruning all plants is covered in more detail in my book, The Pruning Book, available from the usual sources or, signed by me if you wish, here.)

On Going Rosemary Tree Care

Over time, the bushy head grows larger and larger — too large if left unfettered. So pinch back growing tips regularly, which you’ll probably be doing anyway as you enjoy the rosemary added to tomato sauce or chopped and sprinkled on fish. Unless you’re crazy for rosemary, that amount of pruning won’t be enough to contain the ever expanding head.

And below ground, roots eventually fill their flowerpot. Then they will need more room and access to more nutrients. So once a year, in spring, I tip my plant out of its pot, shear off some roots and soil around the edge of the root ball, then put it back in the pot with new potting mix in the space opened up.
Repotting a standard
Right after I repot the plant, I also give it its annual haircut, shearing the head an inch or so back all over with a pruning or grass shears. Water well and watch the plant fill out with new growth.

All those shearings could, of course, be dried for future use. But why do that? You now have plenty of fresh rosemary, year ‘round. Just don’t neglect watering.
Rosemary standard


Bark Giveaway

Walking in the woods or an arboretum this time of year is a good time to play a game of tree identification. You say, “But trees are leafless!” No problem. Often, all you need is to look at the bark.
Paperbark birch bark
You might think a white-barked birch would be an easy identification. Not necessarily. A white-barked birch might be, instead, a European birch (Betula pendula). This one is distinguished from our native paper birch (B. papyrifera) by the dark, diamond shaped fissures on its bark. Or Himalayan birch (B. jacquemontii) or Asian white birch (B. platyphylla). Of course, these last three species aren’t likely to turn up in our woodlands.

I’m often snagged by cherry birch (B. lenta), whose bark isn’t white at all, but whose young bark resembles young cherry bark, then morphs with age into longitudinally elongated plates. The giveaway for cherry birch comes with breaking a small twig and smelling wintergreen.

Trees like red oak (Acer rubrum), sugar maple (A. saccharum), hop hornbeam (Ostrya virginiana), and ash (Fraxinus spp.) are easy to identify once you know their bark.

I can immediately identify hackberry (Celtis occidentalis) because its bark is one of my favorites, pure gray and punctuated by corky ridges.
Hackberry bark
On a clear, wintry day when the sun hangs low in the sky, the shadows create a pattern that recalls those crisp, achromatic photographs of lunar landscapes.

Another of my favorites is American hornbeam (Carpinus caroliniana), whose bark looks like striated muscle. And juneberry (Amelanchier spp.), pale gray with charcoal gray striations. And paperbark maple (Acer griseum), with shiny, copper-red bark.

Paperbark maple bark

Paperbark maple bark

If tree bark offers no leads about a tree, a few dead leaves on the ground or clinging to stems can help out. Beech leaves make identification especially easy because beech is among the few trees that clings to almost all its dead leaves all winter. The lower leaves of some oaks also are reluctant to drop.

Bark, leaves, and aroma aren’t the only things that scream out a tree’s name. Everyone knows the distinctive weeping form and light-colored young bark of weeping willows. Less universally known is the very distinctive form of pin oaks (Quercus palustris): lower limbs sweep downward, mid-height limbs grow out horizontally, and upper limbs point skyward.
Pin oak tree form
On most trees, stems are alternate, that is, they don’t grow directly opposite each other. So if a tree — one that grows wild in the northeast, at least — has opposite stems, I can limit the choices to just a few trees: dogwoods, maples, ashes, or catalpa.

This tree game is more than fun; it’s also useful for identifying firewood. A couple of years ago, I bought some firewood that was billed as swamp oak, which is sometimes a name for pin oak. The firewood’s bark had distinctive, long, flat-topped ridges, which a friend finally identified as belonging to American linden (basswood, Tilia americana). It’s not very good for firewood.

(For a lot more about identifying trees by their bark, in the Northeast, at least, see the book Bark by Michael Wojtech.)

Chestnuts Roasting on an . . . Well, not Exactly

Moving indoors, to the fruits of my labor. Or, rather, the nuts of my labor.

A few years ago I came up with yet another way to roast chestnuts, one that makes the pellicle, that thin, brown skin clinging to the nutmeat, easy to remove. After giving each nut a slit perpendicular to its axis, I spread the nuts in a shallow layer in a covered pan set in a hot oven or on top of the wood stove for 45 minutes. During that time the nuts steam from their own moisture. Then off comes the lid for another 15 minutes of cooking to let the nuts roast and the shells and pellicles (the skin around each nut) turn crisp.
Chestnuts roasting
Massaging each nut without breaking up the nutmeat cracks the shell and the pellicle so that both come off easily — usually. The nuts have the mealy texture of a baked potato and a wonderfully sweet flavor.

Bark Futures

I’m planning to enjoy more fruits — or, rather, nuts — of my labor in years to come. Two Korean pine (Pinus koreansis) trees should eventually get me home-grown pine nuts. As should a lacebark pine (P. bungeana).

The lacebark pine, once it gets older, will also bring me attractive bark to admire as it naturally peels away in brown, rust, green, and cream-colored patches.

Other home-grown bark beauty here includes persimmon (Diospyros virginiana), whose bark is like alligator skin (but not scary), Japanese stewartia (Stewartia pseudocamellia)

Bark of persimmon and sterwartia

Persimmon (left)                           Stewartia (right)

and my previously mentioned favorite, hackberry, a fast growing tree now almost 15 feet tall that I started from seed I pulled off an old tree. The hackberry’s bark is just starting to develop those attractive, corky ridges.
Young hackberry bark