Friday, January 14, 2022

Dry Out and Toughen Up

Baby, it’s cold outside!  While we huddle up to the fireplace or pay the oil delivery man for our comfort, trees and shrubs just stand out there and grin.  How do water-filled woody plants survive freezing, especially when temperatures fall below zero?  Let’s de-mystify this rather complex process.

The cold hardiness of the plant depends upon not just how cold the air turns, but also on rainfall, light intensity, day length, soil fertility, previous high temperatures, and the consistency of temperatures.  The shrinking light and dropping temperatures which accompany autumn are the most crucial of these influences which naturally trigger plants to develop cold tolerance.  The longer a plant is exposed to these changes, the hardier it gets.  Scientists call this “acclimation,” while gardeners know it as “hardening off.”  If frigid temperatures occur before proper acclimation, plant damage may result.  For example, August’s lush English ivy plant may die if exposed to 25 degrees F, while it may withstand minus 30 degrees F in January after being properly hardened off.  Similarly, a winter warm spell might cause a plant to de-acclimate and later suffer if a cold snap follows – just another factor to keep us horticulturists awake at night.

Genetics also play a part.  A red maple (Acer rubrum) native to Georgia will be less cold tolerant than the same species from New England, even if hardened off in the same way.  That is why we often proclaim it is better to buy young woody plants from northern nurseries rather than from warmer climes.  But of course every species, even when properly acclimated and of the hardiest known stock, has its rock bottom temperature it can tolerate.  Witness the crepe myrtles in Charleston, SC but not Castleton-on-Hudson, NY. 

Forgive me for wandering:  my prose has evaded the original question better than a politician before Election Day.  How exactly do woody plants survive winter?  Let’s go down to the microscopic level!  Plants are composed of cells and the spaces in-between cells, known as intercellular spaces.  If an un-acclimated plant is exposed to freezing temperatures, it will be injured because the water inside each cell freezes.  The freezing water expands, the cell walls burst, and the cells die.  Not good.  The hardening off process stimulates the solutes (the stuff dissolved in the water inside the cell) to become more concentrated, or in other words, it encourages the cells to become less watery inside.  These less watery/more concentrated cells don’t freeze as easily.  It’s just like putting antifreeze in your car’s radiator instead of water. 

An interesting aside is that hardening off also makes the solutes in the in-between spaces less concentrated, or more watery.  This might seem dangerous, but freezing water in these intercellular spaces does not normally cause plant damage.  Yet even tough plants have their limits, and at some very cold temperature, the differences of more-solutes-in-the-cell/less-solutes- outside-the-cell cannot be maintained.  The cells then may indeed freeze and die.  Let’s just hope it doesn’t get that cold this winter.

Wednesday, December 29, 2021

New Year, New Sprout

I would have never guessed that Brussels sprouts were favorite pickings for poets.  Linda Lawrence cried, “The mini cabbage will make us gag, that’s only fit for a black bin bag!”  Stuart McLean, writing in brogue as Robert Burns, penned “Some say ye taste like camel droppings, While others think you great” while Robert DeGraff praised his springtime seedlings then mourned their June death by woodchuck in his “Elegy For Brussels Sprouts.”  Sure, some plants inspire poetry – witness Joyce Kilmer’s oak – but a member of the cabbage family?  Perhaps it’s because Brussels sprouts are not so much green but black or white – you either love them or hate them.

But for me there had been a third option.  I loathe to admit it, but up until this fall, I had never eaten a Brussels sprout, so I didn’t know if this crucifer and I were at odds or perfect together.  As a kid, my mother had trouble enough getting me to accept green beans and carrots on my plate, so the poor woman knew better than to push her luck. 

Then I met our Master Gardener Tom, who years ago decided to grow and sample one new vegetable per year.  In this way, he went from being anti-beet to pro-beet.  While getting woozy just thinking of ingesting a beet (they taste like dirt) I suddenly remembered the Brussels sprouts I witnessed, at age 8, in my 4-H leader’s garden.  I was transfixed by the ungainly, towering plants, with weird spatulate leaves and funny knobs up and down the stems.  Maybe this vegetable from “Lost in Space” was not only cool looking, but edible.

Last February, on the advice of another Master Gardener, I went searching for the variety ‘Gustus.’  Just like the closely related cabbage and broccoli, Brussels sprouts are easy to start indoors in April from seed.  After that week of hard frost, I planted them out in late May, begrudging them the ample space (two and a half feet each way) I knew they required.  After supplying some mulch and a handful of fertilizer, I figured I could coast along for the 99 days the sprouts needed for maturity, and I would become a man by eating one.  It was a summer of much rain and little sunshine, not a particularly good vegetable growing season, so I wasn’t banking on a banner harvest. 

God must have wanted me to face this challenge because the plants still grew.  Conventional wisdom says to top the plants in early September to make the sprouts swell.  I did it, and swell they did.  I stalled to Election Day, then asked my wife to cook them up.  Remembering their reputation for inducing flatulence, I was glad my calendar foretold only Zoom meetings the following day.  The sprouts were picked, sliced, and sautéed in olive oil.

Absolutely delicious!  While adding bacon to the mix definitely helped, from now on I will wax poetic o’er the noble sprout.     

Thursday, December 16, 2021

Grow Your Own For Christmas

Can we agree that Americans can’t agree on much these days?  Differences of opinion surround even the Christmas tree supply.  Drought, fires, economic recession and labor shortages support the scarcity theory, but locally at least, firs, pines and spruces are easily found on tree farms and sales lots.  But having been wait-listed for a new refrigerator for ten months now, and seeing shelves bereft of toilet paper and cat food, I’m tempted to grow my own Christmas trees from now on. 

No worry that it will take at least seven years: as a gardener, I know what is required.  To start, site matters.  Most tree species prefer that elusive well-drained, loamy soil that many plants crave, and while Christmas trees can be grown on areas too marginal for field crops, the results may be slower or less optimal.  Wet soils are out – very few conifers tolerate “damp feet” – but overly dry sites can be limiting, too.  Slopes too steep for mowing are not good, and areas of thin soil, ledge, or multitudinous rocks are less than ideal.  Especially windy spots can desiccate needles, which is not good, since even Charlie Brown doesn’t want a brown tree.  Full sun is mandatory – just like tomatoes or dahlias, maximum light is needed to produce bushiness.

But it takes more to make density, and overall shape is crucial.  Most trees are sheared once a year or every-other year, and this takes skill and plain hard work.  A good leader must be maintained, otherwise there is no place to put the star.  And as in mate selection, some people prefer a tall, thin tree while others like shorter and perhaps chunkier.  Just like other forms of garden produce, I’ll tolerate more imperfections in my home-grown Christmas tree than one that costs real money.

Then there are the pests.  White pine or Scotch pine tops will be destroyed by white pine weevil, but pine has few other problems.  Too bad most people (myself included) aren’t big fans of these species for holiday duty.  Douglasfir makes a nice tree and grows quickly, but is susceptible to rhabdocline and other needlecast diseases which turn them a horrendous brown, and again, no one wants a brown tree.  Spraying fungicide, praying for less rain and trying to find resistant types are options, but like many local growers, I’ll avoid Doug-fir.  Fraser fir and balsam fir are better options.

White and blue Colorado spruces have some serious insect and disease pests, but they are otherwise easy to grow and have tough constitutions.  Blue Colorado spruces make for some of the swankiest looking Christmas trees around, and often command a premium price.  Personally, my favorite is concolor fir, a long-needled tree of bluish color with a level of beauty similar to blue Colorado but many fewer problems.  It grows at a slow to medium pace and forms a shapely, dense pyramid.  If I can plant, prune, water, and protect my concolor seedlings, given today’s rate of inflation, they’re better than money in the bank.

Friday, December 10, 2021

All Turned Around

Like discovering the cookie has chocolate chips instead of raisins, two small adventures this summer proved to be better than expected, and they both involved labyrinths.  In August, Master Gardener connections brought me to Elise’s Massachusetts backyard, where the large seven circuit labyrinth she created with found stones and a charming wooden summerhouse in the center made my day.  September’s labyrinth, open to all passersby, I found by chance in a field in Wanakena, a tiny Adirondack Community on the northern edge of the Five Ponds Wilderness.  Both seemed appropriate metaphors for current times, when the twists and turns of our collective public health seem to led us closer to, then farther away from, some resolution of Pandemic situation.

Labyrinths are ancient, mysterious, often found outdoors, and not in the least electronic or digital, all reasons for my enthusiasm.  No one is certain when people drew the first one.  A rock carving of a labyrinth at Luzzanas, on the island of Sardinia, is thought to date from about 2,500 BC.  Others in southern India, northern Italy, and Egypt are all over 2,000 years old.  Cretan coins embossed with a labyrinth design might have carried the symbol around the world.  The Pima tribes in Arizona have woven baskets depicting a labyrinth pattern for centuries.  That so many diverse cultures created labyrinths over thousands of years only adds to the mystery.   

If you’re having trouble distinguishing a labyrinth from a maze, let me try to explain.  Picture a spiral, but instead of the path circling inward toward the center, a labyrinth’s one path loops back and forth, yet still ends near the middle of what is overall a circular creation.  While any size is possible, many of the ancient labyrinths had seven rings or circuits and are said to be “classical.”  A later design, from Medieval times, has the single path traveling around four quadrants arranged in a cruciform pattern, and is sometimes called a “Christian” labyrinth.  The oldest one of these is in the floor of Chartes Cathedral in France.

So what do labyrinths mean?  Some believe they symbolize the process of being born – literally snaking along the birth canal at the start - and life’s subsequent journey.  In Sweden, young people once performed virgin dances in labyrinths, where a boy had to run in, pick up a girl, and run out flawlessly in order to claim her.  Christians have walked labyrinths on their knees as penance, used them to symbolize a journey to the Holy land, or seen them as a metaphor for getting to know God – sometimes one might feel close, other times far away.  Others find that walking slowly through the encircling rings quiets the mind and leads to new perspectives. 

Many of the most beautiful labyrinths are made by cutting paths in a lawn, or arranging rocks in a patch of gravel, making a garden of simple, yet deep, spirituality.  There might even be one in your neighborhood:  check out the comprehensive on-line list created by The Labyrinth Society, which lists 224 in New York alone. 

Wednesday, December 1, 2021

Dahlia Daze

Dahlias represent none of the political correctness found in current gardening circles – quite the opposite.  They take a lot of time and care to grow, being nowhere near low-maintenance.  Many types provide nothing useful to pollinators, and they aren’t native to North America.  They don’t thrive just anywhere, take a long time to start flowering, and look like a train wreck after the first hard frost.  But I still like them.  Here’s how I grow them, and why.

After a few nights of freezing temperatures, last Saturday represented one of the bigger moments in the dahlia-growing year.  Blackened, drooping, and soggy, the shoots were chopped down to stubs and the debris hauled off to the compost pile.  Then careful probing and coaxing with a digging fork revealed the tubers, in all their lumpy, bumpy glory.  Shaking off the excess soil, I carefully moved them to the relative warmth of the basement, let them rest for a day, then bagged them with handfuls of cedar shavings for their winter rest, all the time taking care not to lose the labels.  When I start to reverse this process in May, I hope the tubers won’t be mushy, or shriveled, or chewed upon.  With any luck and some skill, dahlias can keep-on keeping-on for years, perhaps decades, but time in storage is the riskiest part of their lifecycle.

Spring finds me searching longingly for the eyes of the dahlias.  The dormant tubers can be divided, but each must have an “eye” (or bud) to produce a shoot, and these can be elusive, as the dormant tubers look as likely to grow as an old shoe.  I tend to leave several tubers together in a clump, rather than separate them into singles, to increase the chances at least a couple of buds will appear.  Planted a few inches deep, a few feet apart, I give each clump a stake, a tomato cage, a handful of fertilizer and a label.  The buds develop into green shoots nonchalantly at first, in no hurry, but magical nonetheless.  June and July come and go, and on into August, with just leaves and shoots, but finally, flower buds appear.  Late August, September and October are the dahlia paydays, with dazzling flowers produced in abundance, if deer, hurricanes, or other inconvenient spoilers can be kept at bay. 

I meet old friends when my dahlias bloom.  Most of my varieties produce the huge “dinner-plate” type of blooms, 7 or more inches across, so they are big friends, too.  ‘Einstein’ is a smart dark purple, while ‘Zorro’ is a deep red with sharply pointed petals.  ‘Harvest Moonlight’ produces pale yellow orbs, ‘El Sol” blends yellow and orange into a range of fiery shades and ‘Bodacious’ is a bawdy red with yellow on the edges and bottom of each petal, looking like tongues of fire.  Dahlias are the sugary sweets of the garden, intoxicating and addicting.  Eye candy indeed.  No other flower is quite as spectacular, so fulfilling their demands is worth the effort.

Burning Bush, You're Fired!

The fire in my neighbor’s front yard is out:  the burning bushes have dropped their leaves.  An individual burning bush (Euonymus alatus) in its fiery red fall color is impressive, and a long hedgerow is spectacular, which explains the popularity of this species.  But Holy Moses, it’s a spreader!  Seedlings from my neighbor’s shrubs are now sprouting in my backyard, and soon they’ll appear in my woods.  At least twenty-one states have pronounced it an exotic invasive, and several have banned it from commerce.  In New York, it’s “regulated” status does little to stop its sale or spread.  So, let me be a “garden influencer” and ask you to plant beautiful native shrubs instead, so we can extinguish the vagrant burning bush for good.

A top alternative choice is a native called ninebark.  I grow the variety ‘Diablo,’ with foliage of deep purple in spring and summer, turning wine red in autumn.  Large clusters of small white flowers appear in late spring, and the brown exfoliating bark is an added year-round bonus.  Some seasons I give Diablo just a little trim, other years a bit more, this being a shrub you can shape into a variety of forms without a fuss.  It likes full sun and adequate drainage but can adapt to what Mother Nature (and a casual gardener) throw at it.  The nursery industry has finally figured out ninebark is a good thing and now offers other red-leaved types, such as ‘Summer Wine,’ yellow foliage variants like ‘Amber Jubilee,’ and compact forms including ‘Little Joker.’  In comparing them to burning bush, these new ninebarks are just as easy to grow, provide showier foliage all season long and don’t invade the neighborhood with unwanted offspring.

If you can accept bright yellow fall color rather than red, summersweet clethra (Clethra alnifolia) may rock your gardening world.  Native from Maine to Florida, this mound-shaped shrub will very slowly spread, but not in an aggressive way.  One of mine grows under a sugar maple, a testament to its toughness, since little else wants to be there.  High summer is clethra’s season, when hundreds of spikes of tiny white flowers appear, producing a powerfully sweet fragrance.  A noted pollinator plant, honeybees and butterflies will thank you for planting a clethra.  If you want something zippier than white flowers, ‘Pink Spires’ features pink flower buds, while ‘Ruby Spice’ has flowers which remain rose-colored.     

Fancy a Fothergilla?  Those who know them certainly do.  With white bottlebrush flowers in spring and fall color ranging from yellow to orange to red all on one plant, it is a shrub without a bad season.  The flowers of vernal witchhazel (Hamamelis vernalis) are admittedly small, but they bloom in February, the fall color is a good golden yellow, and the plant is bull terrier tough.  And a native who’s fall color rivals the burning bush is red chokeberry (Aronia arbutifolia).  Tough and adaptable, it may be a bit wild for a more refined gardens.  Perhaps plant breeders can turn it into a future superstar.

Thursday, October 7, 2021

As The Worm Turns

Jumping for joy is not how I would describe anyone who meets jumping worms.  Quite the opposite.  Many are grossed out, not a few are thinking of giving up gardening and one gentleman phone caller denounced not only the invasive species website but several government agencies which are probably not involved.  These worms are prolific, bold, and popping up in new places every day.  If you haven’t experienced them yet, you certainly haven’t been hiding under a rock, or anywhere else near the soil.

As gardeners, we are taught that earthworms are good guys.  As they break down organic matter by ingesting it, nutrients plants can use are released.  Earthworm tunneling reduces soil compaction, yet their castings help soil stick together and resist erosion.  Other than the “ew” factor, what’s not to love? 

But jumping worms, including the most well-known species named Amynthas, are not good citizens of the soil.  These Asian imports grow quickly, reproduce rapidly and create large populations of themselves.  They accelerate the breakdown of leaf litter faster than it can accumulate on the forest floor, leaving bare soil.  In turn, soil temperature and moisture buffering decreases, seeds for new plants don’t germinate and beneficial soil organisms suffer.  I only have to look at the woods behind my house to see this, where there are very few young native trees coming up to replace the old fellows and virtually no shrubs or understory plants.  But the bad news doesn’t stop there, according to the folks at Great Lakes Worm Watch, part of the University of Minnesota.  They write, “There is also fascinating evidence emerging that the changes caused by exotic earthworms may lead to a cascade of other changes in the forest that affect small mammal, bird and amphibian populations, increase the impacts of herbivores like white-tailed deer, and facilitate invasions of other exotic species such as European slugs and exotic plants like buckthorn and garlic mustard.”  In gardens and on lawns, jumping worms leave castings resembling coffee grounds and sometimes cause plant decline and soil subsidence.  Occasionally hundreds of jumpers end up on sidewalks or in basements. 

Jumping worms not only leap, but wiggle manically when disturbed, flipping like a fish out of water, and can cruise across a lawn like a snake with an agenda.  If you’re familiar with standard earthworm behavior, the show put on by a jumping worm is sure to shock and surprise.  For identification purposes, also look carefully.  A mature specimen of a jumping-type species will measure one and one-half to eight inches long, and will have a smooth, milky pink or white to gray band (clitellum) near the head.  Other worms have a raised or saddle-shaped, segmented clitellum and a more ho-hum demeanor.  In our area, they spend the winter as tiny cocoons, first appear as adults in spring, and grow until soils cool in fall.  Last year’s spring drought suppressed them, while this year’s excessive rainfall favored them.  Control options, beyond picking and destroying, are not well-developed.  Frustrating and alarming, indeed.