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.

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. 

Savoring Sumac

Hydrangeas are in, yews are out.  Interest in vegetable gardening swings with the tides of economics and pandemics.  In the hippest neighborhoods, spider plants in macrame hangers have even made a comeback.  Public opinion on native plants is on the way up, too.  In my collegiate plant identification classes, our professor would say “it’s just a native,” somewhat disparagingly, when we looked at an eastern red cedar or tuliptree.  Today, those on the front of one of the trendiest gardening curves are going native and banning non-indigenous plants entirely, or are trying to plant gardens which are composed largely of native plants.

Some natives, such as bottlebrush buckeye and the sugar maple, are attractive and easy to invite into your personal landscape.  Others, like poison ivy, would only be employed in the garden of a sadist.  I’m interested in the plants which people deem in-betweeners, such as sumac.  In England years ago, I was approached by a nicely dressed gentleman, who guessed I was an American.  “Our favorite plant comes from your country,” he said.  I guessed it must be the giant redwood, a certain hybrid tea rose, or perhaps a rare orchid.  “No,” he replied, “it is sumac.  It has the most magnificent fall color and beautiful fruit!”  Our new love of natives hasn’t discovered sumac yet, so I’m here to promote its case. 

Locally, sumac species such as staghorn (Rhus typhina) and smooth (Rhus glabra) grow wild in hedgerows, right-of-ways, and abandoned fields.  This “wildness” may be part of the discord, since sumac defies pruning into meatballs or hockey pucks and will always look shaggy and primordial.  Sumac supporters point to cultivars with dissected, lacey foliage that is prettier than the common types, such as Rhus typhina ‘Dissecta’ or ‘Laciniata,’ both with finely cut leaves.  I’ve had ‘Laciniata’ in my garden for decades, and found it not wildly rampant from seed or sprouts.  While it has moved fifteen feet from its planting spot, seeking more sun, the very few unwanted runners have been easy to remove.    

“But it is poisonous!” the sumac-phobes will proclaim.  Nonsense.  These sumacs are fine to touch.  In fact, poison sumac (Toxicodendron vernix) grows primarily in bogs, has white (not red) berries, is closely related to poison ivy, and is not common locally.  Once again, the name is the problem, not the plant.  Perhaps sumac needs a new image and a re-boot, a process which succeeds with some politicians and certain consumer brands.      

Sumac is useful, too.  Legendary Master Gardener Winnie Lustenader, an edible wild plant aficionado, offered up a truly delicious lemonade made from sumac berries.  Sumac fruits also make excellent fuel for a beekeeper’s smoker, the device used to calm honeybees while the prodding around in their hive.

In closing, I must quote the famous plantsman Michael Dirr, who opined in his Manual Of Woody Landscape Plants, “Europeans have long appreciated Rhus glabra and Rhus typhina.  Perhaps, someday, Americans will become more introspective and appreciative of our rich woody plant heritage.” 

A Brush With Greatness

Sometimes the worst garden disasters create happy endings.  This was the case for our Norway spruce.  A towering giant, it was hit by lightning in July 2015, giving it a fatal trunk crack from top to bottom.  While I was glad the tree took the jolt rather than the house, its removal left an ugly blank patch which quickly started to fill with weeds.  Faster than an American Pickers guest star at a tag sale, I started acquiring and installing new plants, including two winterberry hollies, a spicebush, a moosewood maple, and best of all, a bottlebrush buckeye.

If you look in your woods for bottlebrush buckeye (Aesculus pavia) and don’t find it, please forgive me.  I admit that calling it native is a bit of stretch, since the most extensive natural populations are found in central Alabama, with nary a sprig in New York.  But get to know this outstanding woody ornamental, and you’ll be hooked, too.  The Morton Arboretum calls it a handsome shrub with memorable flowers, while British botanist William Jackson Bean wrote “no better plant could be recommended as a lawn shrub” and Wayside Gardens proclaims it “one of the best flowering shrubs for the summer.”  While I freely admit that Wayside doesn’t go in for understatement regarding anything they sell, for an Englishman to give high praise to an American plant, it has to be good.

So, let me tell you why bottlebrush buckeye is a plant of special merit.  First, it has great foliage and form.  Its medium green leaves are palmately compound, giving it a unique texture, and it develops into a dense mound ten to twelve feet high and at least as wide.  Unless you want to block the view out your first-floor windows, don’t plant one near your house.  Instead, locate it on the margin between lawn and woodland, where it excels.  Bottlebrush might also be grown as a small tree, but the plant’s spreading nature would then require management, which seems a shame.  Better to plant it someplace where you can let it branch to the ground and spread a bit.  As garden writer Margaret Roach keystroked, “Give it plenty of room–and I mean plenty–and it will make a beloved companion for decades to come.” 

Plantsman Michael Dirr wrote “there are few summer flowering plants which can rival this species.”  The delicate white flowers are borne in cylindrical panicles up to 18 inches tall, dozens of which will appear on a mature plant in late July.  Although the name “bottlebrush” sounds a bit prosaic, it aptly describes the form of this floral display.  The buckeye fruits, which are light brown nuts inside pear-shaped capsules, aren’t prolifically produced here in the north.  Bottlebrush buckeye rarely needs pruning, unless planted too close to the house.  Southern Living’s Steve Bender sums up by stating:  “People often expect the prettiest plants to be a pain to grow, but that certainly isn't the case here. Bottlebrush buckeye needs moist, well-drained soil and partial to full shade. That's it.”

Let It Be

“Just sit back and watch it grow!” was a favorite line proclaimed by radio talk-show personality Ralph Snodsmith after he dispensed gardening advice to a caller.  The onetime horticultural guru of New York’s WOR-AM, Ralph knew that most plants want to grow if we gardeners just give them the right conditions and care.  But sometimes, a plant will take its own sweet time deciding if it is going to live or make a one-way journey to the compost pile instead.  This has been my experience with a species called Acanthus spinosus, a.k.a. bear’s breech.

Hailing from the Mediterranean, Acanthus spinosus has much to recommend it as a garden plant.  Growing in a large clump, the attractive, dark green, glossy foliage is deeply cut, thistle-like, and only modestly barbed.  It is resistant to insect pests and rabbits.  Spikes of snapdragon-like flowers in shades of pale and dusky pink are distinctive and rise to three feet or more above the leaves.  The ancient Greek architect Callimachus was a fan of this plant, decorating the top of his Corinthian columns with Acanthus leaves, and it still a common design element in contemporary art and design.  Often commonly called “bear’s breeches,” the plant has nothing to do with the slacks Smoky wears or we wish Yogi would put on, but derives from the bear claw-like flower bracts.  Other common names are oyster plant, sea holly and bear’s foot.  Such a historic plant with a dignified demeanor certainly should have a loftier moniker.       

Having seen Acanthus species thriving in warm southern climes, I was surprised to see it living large in Ithaca, New York, as well.  At the time, I had assumed that we were too far north to grow it successfully, but if they could grow it in Ithaca, well by golly, it should grow in Castleton-on-Hudson, too.  So I procured a plant, set it into my nice loamy soil in a backyard spot, and sat back to watch it grow, letting Ralph be my guide.

That was twenty years ago.  For at least fifteen ensuing summers, the Acanthus would produce just a modest leaf or two, never more.  It didn’t look sick, but refused to thrive.  I kept the weeds and neighboring perennials at bay, and watered it occasionally, but the status quo was maintained.  For perhaps a decade I hardly gave it a thought, but I let it be.

In 2016, the Acanthus woke up, becoming fuller and downright lush. I’m not sure what sparked the change:  the mediocre Batman movie, Brexit, presidential politics?  Perhaps that difficult year inspired it to adopt a “now or never” attitude in terms of its own survival.  In 2017, it produced its first flower spike, and this year it sports a half-dozen more, finally making something to see.  I can finally say “I grow Acanthus spinosus” and not be ashamed of my results.

I’m glad I let this late-bloomer do its thing, get it’s grove on and finally rise up singing.  The Acanthus has taught me patience.     

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.