A Green Grand Canyon

Being a plant guy, I can’t help but turn any outdoor vacation into a busman’s holiday.  On a recent trip to the Pine Creek Rail Trail for a 120 mile bike ride, I knew I would enjoy cycling amongst the mountains, seeing the landscape and maybe spotting some wildlife.  I also ended up, no surprise, looking at a lot of plants.  While much of the flora is the same as we see here in the Hudson Valley, it was fun to spot the differences among the wild plants in “the Grand Canyon of Pennsylvania.” 

I was rather skeptical about this loftiest of landscape titles, but Pine Creek does indeed flow through a narrow valley up to 1,450 feet deep; standing on top we were above the vultures and fog.  While a good part of the area is now protected, it is a site of former widespread devastation.  In 1798, the first of the giant trees, centuries old, were felled and sent downstream to hungry sawmills.  Soon tremendous rafts of timber choked the creek.  When the trees near waterways were gone, railroads moved in and climbed up the adjacent valleys.  By the dawn of the twentieth century, the canyon was stripped bare, only thorny brambles and mountain laurel remaining.  Then, in 1903 wildfire swept through, opening the ground up to landslides.  The timber companies made their final profits selling the exhausted land to the state. 

Looking at Pine Creek today, it’s hard to imagine the transformation from hell-on-earth green-cloaked paradise.  Bears, deer and rattlesnakes crossed the trail in front of us, and eagles soared overhead.  River birches, with their flakey bark of gray, cinnamon, and tan, lined the banks of the creek.  They don’t mind life clinging to a streambank or the occasional flood.  Stock-straight sycamores in uncountable numbers grew along the trailbed, their trunks like Greek columns holding up a leafy canopy.  Tulip trees, their show of yellow and orange flowers past but easily identified by their distinctive four-lobed leaves, were another species common in the canyon but rarer in our neck of the woods.  Exotic invasives also call the canyon home, including not a few Norway maples and many acres of Japanese bamboo.  Since I was on holiday, I tried to keep my blood pressure down, but closing one’s eyes isn’t good while riding a bike.

I was especially happy to see rosebay (Rhododendron maximum) growing in its wild state.  The species name “maximum” is a great descriptor.  Rosebay easily grows to ten feet high, sometimes 20 or more, and when its stems collapse, they root and form colonies up to 25 feet across.  The huge, droopy evergreen leaves have been likened to donkey’s ears.  Large clusters of pink buds open to snowy white flowers.  It likes part sun, part shade, damp soil that’s not too wet, and may choose to live on rocks or in swamps.  Creating the right environment for it would be impossible in my garden, so I gave it my regards in Pennsylvania.     

An Onion Grows In Kinderhook

It might have been a dream, but I think I remember an old Jeopardy! episode with the category “Alimentary Alliums.”  In it, Alex asks, “This rare member of the onion family is found on sea cliffs along coastal Cornwall and Dorset” and a contestant volunteers “What is Babington’s Leek?”  Given the scores of edible members in the Allium tribe, an entire Jeopardy game could be dedicated to uncovering the fascinating details of onions, shallots, leeks and garlic.  And let’s not forget chives, Allium schoenoprasum, a plant which taught me that some alliums also have beautiful flowers.

And that is what I’m thinking about today, onions grown not for their culinary usefulness but for their value as “eye candy,” which I call “ornamental alliums.”  Last weekend, I biked through lovely Mills Park in Kinderhook, where a large floral display including perennial blue flax, white narcissus and magenta alliums got me to pull over for a closer look.  Unfortunately, my firsthand knowledge of ornamental alliums is slight, so I won’t be participating in onion-themed Jeopardy! anytime soon.  I therefore won’t hazard a guess as to exactly which allium grows in Kinderhook, but I must say they were impressive.

Many ornamental alliums are described as a large ball of small star-shaped flowers in shades of lavender, magenta, purple or violet.  These round “umbels” are borne on long, thin green stems, with just a few often non-descript leaves at the base.  Allium hollandicum, sometimes called the Persian onion, is a typical of these, growing to between one-and-a-half and three feet tall.  The variety ‘Purple Sensation’ has darker flowers and has earned an Award of Garden Merit from the Royal Horticultural Society in the United Kingdom.  Allium ‘Globemaster’ is a hybrid cross between A. christophii and A. macleanii and is sterile, so it doesn’t spread promiscuously, and grows stems between three and four feet tall with a lavender sphere on top.  Allium giganteum, which unsurprisingly is called the giant allium, boasts softball-sized purple flower clusters on towering stems of five feet.  Despite its grand size, sources say it doesn’t need staking.  While these large-type alliums are individually impressive, one solo plant looks silly, so garden designers say it is best to plant them in groups of at least five to seven. 

More variations abound.  For blue globes of flowers, try Allium caeruleum, which grows to two feet.  Small, egg-shaped purple flower heads on very thin stems characterize drumstick allium (Allium sphaerocephalon).   Turkistan onion (Allium karataviense) has fat, attractive leaves, floral globes of pale pink, and grows only a foot tall.  Lady’s Leek (Allium cernuum) boasts delicate, open flower sprays of white, pink or lilac and, like most ornamental alliums, needs well-drained soil and not wet feet.    Tumbleweed onion, Allium schubertii, grows about two feet high and has a loose sphere of lavender flowers of varying lengths, giving it the bizarre appearance of a firework or space alien.  It also makes a good dried flower.  There are dozens more, providing an ornamental onion for every taste.    

They've Got You Covered

I believe it was Ben Franklin’s gardener who said only three things are certain – taxes, death and weeds -  and we’ll all be pushing up the latter after death.  Abetting weeds is not a comforting thought, so after I’m gone, I hope to be fostering groundcover.  These low-growing plants, often spreading by stolons or rhizomes, can successfully hold the soil in place, conserve soil moisture, increase organic matter and battle weeds – all things I’ve spent a gardening lifetime striving toward.

Let me dispense with some obvious choices first.  Myrtle (Vinca minor) is tough but can get invasive; same for lily-of-the-valley (Convallaria majalis) and carpet bugle (Ajuga), which often ends up in the lawn.  Don’t plant goutweed (Aegopodium podagraria) unless you want only goutweed, everywhere.  Pachysandra spreads politely but effectively, making a virtually foolproof evergreen carpet.  At least in my garden, it gets high praise.

For partial shade, barrenworts (Epimedium species) can’t be beat.  Their patches of heart-shaped leaves spread slowly, with tiny white, yellow or red flowers in early spring.  Wild blue phlox (Phlox divaricata) is a native woodland wonder, with pale blue flowers over a creeping mat of foliage.  The flowers of lungwort (Pulmonaria species) are deeper blue, and the green foliage is splattered with silvery spots.  Thought to cure pulmonary diseases in ancient days, its common name is no marketing asset to today’s garden center industry.  Sweet woodruff (Galium oderatum) has a more cheerful moniker and features tiny white flowers and whorled foliage all on a plant less than six inches tall.  It is said to the basis for Maitrank, the German wine traditionally imbibed on May 1.  Favorites for foliage of similar stature are the trans-oceanic cousins, European wild ginger (Asarum europaeum), with shiny green, kidney-shaped leaves, and Canadian wild ginger (A. canadensis), with a matte finish.  The tiny purplish flowers are so low only the slugs (their pollinators) and extremely curious gardeners can even locate them.  I’ll finish with the wee-est of all, Kenilworth ivy (Cymbalaria muralis), a lilac-flowered crack-filler which used to cover our old brick steps before the mason made them safe again.  It now resides on the greenhouse floor, where rules of horticultural sanitation say it must not remain, although pulling it out is as heartless as throwing an old dog off the sofa.

Need something taller?  Carex morrowii ‘Ice Dances’ looks like a spider plant, with its grass-like leaves edged in white, and makes a mass 18 inches tall.  From the same genus, Carex ‘Blue Zinger’ spreads faster but is a plain, dark green.  At two feet tall, Variegated Solomon’s seal (Polygonatum odoratum ‘Variegatum’) is lovely, with arching stems, pendant flowers and green-and-white leaves all on a tough plant.

In sun, low growing sedums, such as Sedum kamtschaticum, S. acre and S. reflexum survive in the worst soil and provide textural diversity with few maintenance needs.  Similarly rugged is big-root geranium (Geranium macrorrhizum), with pink spring flowers, evergreen foliage and a spicy fragrance.  Of course, don’t forget lamb’s-ear, thyme, catmint, moss phlox – I’ll be an old man before I can list them all.

Boxwood Back From The Blight

Boxwood, those plush green globes and mini-hedges popular with the highest gardening elites down to the lowliest discount garden centers, fell from grace about a decade ago with the advent of a deadly disease called boxwood blight.  In the early days, photos of giant piles of dead boxwoods culled from nurseries and lush gardens browned by the blight circulated as warning stories.  But what has changed since then?

First, a little review.  Boxwood blight showed up in several east coast locations simultaneously during the summer of 2011.   Like Stonehenge and superconductivity, no one knows its exact origin, but boxwood starting dying of the strange fungus in the United Kingdom way back in the 1990’s.  The first symptoms that occur are light to dark brown, circular leaf spots with dark borders. Infected stems have dark brown to black, elongated cankers. Rapid defoliation occurs, especially in the lower canopy of the shrub.

Disease transmission primarily happens through movement of infected plant material, contaminated landscape and garden tools, and rain/irrigation splashes.  Fungal spores are spread by wind, rain or sprinklers.  Because spores are sticky, they can potentially be spread by contaminated clothing and animals, including birds.  Spores on infected leaves that have dropped can survive five years. Warm and humid conditions cause the fungus to spread quickly.  Gardeners are urged to clean their tools, never water boxwood from above and replace dead boxwoods with something else.  The fungicide recipes and regimes required to keep boxwood green resemble a cross between Baked Alaska and Gateau St. Honoré and are unsustainable.

In terms of dollars and cents, boxwood is a fairly large business, with sales of $126 million annually on 11 million plants, so it’s worthwhile for the nursery industry and government to become involved.  Adversity also inspires genius, and it has gotten some plant pathologists looking for possible solutions in tiny places.  One group of researchers found a bacterium they’ve named SSG for its size and shape (small, sage green) in the leaves of a very blight susceptible boxwood cultivar called ‘Justin Brouwers.’  In laboratory experiments, SSG interrupted the lifecycle of the blight pathogen at several stages and killed blight spores.  When sprayed on diseased leaf litter under boxwood plants, SSG reduced the blight by 90%.  Their conclusion is that SSG “offers great promise for sustainable blight management in nursery production and in the landscape.”  Other biocontrol agents being studied include another bacterium called Pseudomonas and a fungus named Trichoderma.     

But what if you want to buy the most blight-resistant boxwood you can find today?  Scientists at the US Department of Agriculture compiled data from several previous studies to find that answer.  According to their list, Buxus microphylla ‘Little Missy,’ ‘Winter Gem,’ ‘Compacta’ and ‘Green Beauty’ are among the most blight resistant types out of 131 examined.  Before buying, acquaint yourself with what boxwood blight looks like. When shopping read the labels carefully, and examine the plants with even more scrutiny.  After planting, continue to keep watch.  Hopefully, all will remain green.  

Trouble Beneath The Snow

April, and the trees are a-budding, the bulbs are a-blooming, and the lawns are a-greening – except for a few lawns, which have big brown spots.  This I know, partly because I’ve received some photos from distressed homeowners, under the title “Why Did My Lawn Die?” and partly because my own lawn has brown spots, too.  It might not surprise anyone to learn that the problem has roots in 2020, but it is odd to learn that a common phenomenon – snow – is involved.  Let me tell you about the snow molds.

A lot of fascinating fungi live hidden in lawns, waiting for  just the right conditions to show themselves, and this is certainly true of the snow molds.  We’ll focus on the two most common types, called pink and gray.  Unlike most plant diseases, which require warm or at least moderate weather, the snow molds like it chilly.  Their idea of a good place to live is in the top layers of unfrozen soil with a nice, insulating cover of snow.  The longer the snow stays in place, the more damage these diseases can cause to the grass.  So, typically, the farther north you live, the more likely are to have snow mold appear on your lawn.   

Pink snow mold, the flashier of the two, gets its common name from its mycelium (body) color and the fact that the spots of dead grass it makes often turn pink on the edges.  Sometimes these spots are dramatic, with bleached, matted grass blades surrounded by a bright Crayola-like band, other times the patches are more diffuse.  The weather we love to hate in the Northeast - repeated frosts, cold fogs, slow and drizzling rains, with temperatures from just above freezing to almost 60 F – are joy to pink snow mold.  When the sun comes out and things dry, pink packs it in.  Kentucky bluegrass and fine-leaved fescues show more resistance than other grasses.  Those of you who like a good scientific name will appreciate knowing this pathogen is technically called Microdochium nivale.   

Gray snow mold makes bigger patches of trouble, sometimes measuring from one to three feet across.  The grass will often be flattened, matted and a pale straw or grayish color.  But there is a little shred of good news here.  While its damage may be more dramatic than pink, gray often doesn’t kill the grass, and a lawn may have a better chance of recovery.  Interestingly, it takes a longer period of snow cover for gray snow mold to develop and spread than for pink, but gray snow mold is more common on home lawns.  Also, if a lasting snow doesn’t appear until well into January, the chances of a banner year for the snow molds decreases, but you won’t catch me feeling sorry for them.

What you do influences these creatures.  Avoid fertilizing your lawn late in the season, but keep mowing until growth stops.  Avoid making giant snow piles.  In spring, patches can be raked, re-seeded and lightly fertilized.    

Plants Cleverly Endure The Big Chill

As a warm-blooded creature, all I can conclude is that January is about basic survival.  Howling wind, falling snow and plunging mercury has my old house’s furnace working double-time.  I’m huddled under an afghan, counting on my laptop to keep me warm.  Perhaps it would be easier to go dormant like the plants outside, which are just as alive as me yet somehow better equipped to beat the chill.  So how can species such as oaks and maples, composed largely of water, survive double digit negative numbers while water itself freezes at a rather balmy 32 F?

For such woody plants, building up cold tolerance is a process.  Stage one hardiness is triggered by the shortening daylight and cooler temperatures of autumn, which stop growth, encourage the shedding of leaves, and trigger other chemical reactions which are not completely understood.  Just this decrease in light and temperature helps, allowing a stem to remain alive down to about 0 F, but no more.         

Next comes something called “deep supercooling.”  This ability to suppress the freezing of sap within plant cells is also somewhat of a mystery, but it allows many species to survive down to -40 F.  Part of the secret here are recently discovered “anti-freeze” proteins, which inhibit the growth and recrystallization of ice within the living part of the cells.  Certain animals can produce anti-freeze proteins, too, which led some scientists to insert an arctic flounder anti-freeze gene into sweet corn back in the ‘90’s, hoping to make a hardier crop.  While such tinkering with Mother Nature gives some people the chills, growing corn in Alaska would be super-cool.

The toughest of the tough – plants like paper birch, willow and red-twig dogwood – have another trick up their trunks to survive even colder conditions:  dehydration.  As temperatures plunge, water moves from inside the living cells into the dead cell walls, causing two good things to happen.  First, water freezing in the cell walls causes no harm to the plant, since the cells walls are dead.  Second, the sugars and other compounds inside the cell become concentrated, lowering the freezing point.  This parallels the practice of putting anti-freeze solution in car radiators, so your Dodge Aspen is more similar to a quaking aspen than you might otherwise think.   

Evergreen rhododendrons have a few tricks of their own, too.  They look pitiful when their leaves droop and curl on a frigid day, but it’s just a defense mechanism.  Rhodos loose water through stomates, tiny openings on the undersides of their leaves, and the drooping shelters stomates from the wind.  The trouble really starts when the soil freezes, cutting off the water supply from the roots, and causing browning of the foliage, a.k.a. winter injury, to occur.  But amazingly, some cultivars have even this figured out.  Rhododendron carolinianum ‘P.J.M.,’ one of the hardiest available, can lose up to 70% of its leaf moisture and be just fine, while the more tender Rhododendron catawbiense ‘Grandiflorum’ is injured when only 50% dehydrated.

Still shivering?  Pass the arctic flounder, please.

Getting A Head Start

Gardening guru Jerry Baker said plants were like people, and I believe seeds are, too.  Some seeds grow easily under many conditions, like your friend who thrives no matter what life gives her.  Similar to your black sheep cousin arriving on your doorstep, some seeds germinate unexpectedly by the back steps, in the driveway gravel, or in the compost pile.  Others are as fussy as your little sister, needing precise coddling to get moving.

This last group of seeds generally requires starting indoors well before planting out in the wide world.  The tiny print on the seed packet gently suggesting “start indoors eight to ten weeks before planting out” is a warning to plan ahead.  Other crops, such as tomatoes, germinate easily but take a good three months or more to fruit, so giving them a head start indoors assures production in the current calendar year. 

After assessing which seeds need what conditions, assemble your gear.  I like to use a soil-less mix, containing peat, perlite and vermiculite, specially formulated for seeds.  It’s lightweight, drains well, and contains no killer pathogens.  You can make your own mix, and even pasteurize it in your kitchen oven, but the stink and mess can substantially reduce household harmony.  I also use professional grade plastic cells, those familiar “six packs” seen in nurseries, but a wide array of food containers, cleaned and given drainage holes, may work just as well.  Containers can also be fashioned as soil blocks, made from peat or coir, or created from newspaper. 

Seedlings need light, a tricky proposition if you rely on a windowsill location here in sun-deprived upstate New York.  While the daylight is incrementally getting longer, cloudy days and low light intensity tend to leave seedlings spindly and weak.  Luckily, we’ve got artificial options.  Swanky “growing systems” with stands, trays, and lights are attractive, durable and easy to use.  Still, they’re too costly for thrifty me, who relies on classic “shop lights,” the four foot fixtures with two fluorescent bulbs.  Newer T-8 bulbs are longer lasting and more economical than the older T-12 type, while LED bulbs are more efficient still, and seedlings of most plant species will thrive under all of them.  Special “grow lights,” which produce more red and far-red light, are not needed for seedlings, but are a must if you’re trying to grow flowering plants under lights, such as African violets or orchids.

A swift kick in the bottom gets me motivated on Monday morning; a seed’s equivalent is bottom heat.  Put your seed tray on a heat mat, plug it in, and watch germination time drop as the seeds pop.  Put the tray on a warm surface – the top of the refrigerator or furnace – to get the same effect.  While many seeds will grow at normal room air temperatures, extra root-zone warmth helps.  The biggest danger is over-exuberance.  If your ‘Lemon Gem’ marigold packet advises six weeks start time, plant them on April 1, not February 1.  Seedlings get cabin fever just like the rest of us.