INVADED, BY NATIVES



Sweetgum (Liquidambar styraciflua)
is native to my neighborhood...

            In recent years, gardening with native plants has come into fashion. Again. When Tim and I get asked to design one, we give each other secret little smiles and ask the potential client, “Native to where?”

You may recall that, a few posts ago (“Wind and Weather,” August 17^th), I vented my annoyance with the NWS and NOAA for using the word “normal” for their computed 30-year averages. (Check out my new gadget at right, Acronyms Explained.) When I read an exchange in American Nurseryman about regulating “invasive” species—those quotation marks again!—I had a similar reaction. “Native” is as nebulous a concept as “normal.”  



...while Rhododendron catawbiense,
native to western North Carolina,
does poorly on the coast; and...

            I’m not just being supercilious and snotty here. Most people, even when impelled by environmental earnestness, don’t have any concrete idea what “native” means. Newcomers here often consider hybrid azaleas, crape myrtles and gardenias Southern natives. Nope, they all originated in China and/or Japan. Tomatoes, some rhododendrons and hemlocks do come from North America—just not this part of it. In the 500 or so years since first darkening the doors of this continent, Europeans have introduced about 50,000 plant species. These introductions include about 90 percent of our present food crops as well as a hefty slice of the ornamentals pie. And that doesn’t include “exotic” animal species like horses and nutrias; insects like European honeybees, some earthworms, fire ants, and the emerald ash-borer; plant pathogens like Dutch elm disease, chestnut blight, and the fungus responsible for sudden oak death; or human diseases like West Nile virus and avian flu. Makes you think, doesn’t it?  



...and crape myrtles
(Lagerstroemia indica x fauriei)
came from the Orient.

            Over time, many introduced species have interbred with their indigenous counterparts, producing natural hybrids that muddy genetic-origin waters more than a whole university-full of hyper taxonomists. 

           

            People who really, really want a native garden should buy a large parcel of land and just encourage (and perhaps impose a little structure on) what’s already there. Indeed, I would argue that all “gardens” are by definition artificial, the result of human will worked on the land. 

            Philosophy aside, the flip-side of what makes a species native is what makes one non-native. Except for recent introductions whose provenance is (somewhat) known, it can be really hard to tell who’s whose horticultural daddy. Sylvan and Wallace Kaufman point out in the first three chapters of their excellent book, Invasive Plants (see Good Reads at right), that all “natives” were once successful invaders. 

Trans-Atlantic transport
circa 1670

To illustrate the difficulty inherent in defining “native,” I present a Homo sapiens example. Both Tim and I were born in United States to parents who were also born in the United States. No one from either family (the documented ones, anyway) is indigenous to the eastern U.S. My ancestors hailed from all over Western Europe, and it’s anybody’s guess how they ended up there. Two or three lines of my family had established themselves in North America by the latter half of the 17^th century. Yep, I’m certified DAR and UDC (check out that acronym gadget mentioned above). But am I more native than Tim? Both sets of his grandparents sailed from Ireland in the 1890s, some 220 years after my folks got here. Besides, with all due respect, even the “Native Americans” came from somewhere else—can you spell “land bridge”?



Welcome to the New World,
circa 1900

            The Kaufmans assert that “native” does not always mean “better,” nor can we assume that exotics always cause “harm” in “native” environments. This issue is about as far from cut-and-dried as you can get. Nonetheless, in our crisis-of-the-day national mentality, it’s just a hop, skip and a jump for some people to move from neutral non-native to frightening invasive.



Invasives poster child,  kudzu
(Pueraria lobata)

            Remember those 50,000 plant species introduced to North America since the 1500s I mentioned a while back? Well, about 5000 of those have escaped cultivation and moved in with the 17,000 “native” species. How did these foreigners get into the wild? Birds and rodents relocate lots of pre-fertilized seeds. Water and wind do their bits, carrying seeds and even entire plants over long distances. Large mammals join the party by transporting seeds and bits of roots on their fur or pants or shoes. Most new arrivals have proven to be good neighbors, behaving well and blending in nicely. On occasion, however, some thug will throw its weight around. The buzzword “invasive” applies to these rogues, the cause of all sorts wailing and gnashing of teeth among environmental purists and legislators.

The best definition of an invasive is “a plant that is too successful.” Its trademark trait is the speed with which it takes over an area. Examples of When Plants Go Bad in the South include kudzu, Asian wisterias, Japanese honeysuckle and Chinese ligustrum (a.k.a. privet). New York battles purple loosestrife and milfoil. In the Middle Atlantic states and the Northeast, burning bush, barberries, and Miscanthus cause problems. South Florida fears nandina, melaleuca, and many, many others. The Irish suffer from troublesome volunteer butterfly bushes growing in their gutters and chimney pots. And so on.



The Invasives Alert page from
June 2011's Fine Gardening

            “Invasives” appear globally, but are they necessarily a problem? Some scientists theorize that more than 90 percent of all species that ever lived on earth have gone extinct. (How did they determine that? I don’t know.) Must we assume that “change” equals “harm”? We cannot turn back the clock to the time of North America’s virginity. Isn’t it possible that what we perceive as “invasiveness”—or “man-made global warming”—is really part of an on-going process, and that maybe everything, even Homo sapiens, only gets to stay on the stage temporarily?

             There’s also the local character of invasiveness to factor in: for example, kudzu’s not a problem in Minnesota.

           

Anyway, the challenge facing both the horticulture industry and gardeners boils down to avoiding being part of the problem. Most states’ Cooperative Extensions post lists of local potential invasives on the internet, as do watchdogs like the Nature Conservancy, the Invasive Plant Atlas, the USDA Plants Database, the National Invasive Species Information Center, and Invasive Alert. Connecticut leads the way in outlawing flora non grata, legislating against anything that’s invasive anywhere. (In fact, I’m considering relocating there, as they must have already handled the important stuff like universal health care, unemployment, education, immigration problems, and the shrinking of the middle class. You think?) If you suffer from technophobia, as I do, call your Extension or State Department of Agriculture: they will sigh heavily and eventually mail you something. The Kaufmans’ book has a long list of sources of information as well.



Looking for alter-"natives"?

            Some people think the only way to combat invasiveness is to use only natives, and write hefty tomes on the subject (like Armitage’s Native Plants for North American Gardens and Native Alternatives to Invasive Plants—see Good Reads at right). Seems to me a lot like throwing out the baby with the bath-water, however. Your real-life options? Refuse to use plants like Japanese honeysuckle and barberries, boycotting the nurseries and garden centers that grow and sell them; or keep a tight rein on your beloved specimens, including provisions in your will that potential invaders be immolated with you on your pyre.



Check out these books by 
Allan Armitage
or C. Colston Burrell

             A parting thought: in the August-September 2007 issue of Horticulture, Carol Reese responds to a reader letter about her recommendation of a plant considered to be an invasive in some places by saying, “My main concern is loss of habitat, and humans are the worst of the invaders… [E]cologically sensitive landscapes… need not be all native, especially if the plants are those that can be grown without chemicals… The Earth is in a constant state of flux, which does not relieve us of responsibility, but requires us to make the best choices we can with what information we can gather.”

 

            So get informed before you plant. And whatever else happens, don’t you be slipping in a cutting of kudzu to cover your new pergola. Unless you live in North Dakota.

                                                                                    Kathy

P.S.—You may want to invade Plant Delights Nursery’s Fall Open House. It's being held the weekends of September 9-11 and 16-18. Weather’s nicer now, if you weren’t up to facing the summer do.

SOME HURRICANE DOGGEREL

            Tropical cyclone activity is not exactly unheard-of here on the North Carolina coast. I admit, it's been 12 years since Floyd dumped 40 inches of rain on us back in 1999, but residents understand what a hurricane is, and all the options for preparing for an incoming one. Our media types, however, must have lost their long-term memories or, perhaps, grew up in caves in Wyoming, because to a man they act like every potential big blow is Armageddon redux.

           "Sixty-five million people imperiled by Irene!" Matt Lauer intoned on The Today Show. (Or, at least, that's what my son Sam told me. Our television stays silent and blank most of the time. I follow important weather events from the National Weather Service website, where pictures trump the thousands of words spewed by broadcasters.) But really—what tommyrot. The implication is the Northeast Corridor is peopled exclusively by idiots. Matt really shouldn’t judge everyone by himself.

            Hyperbole is alive and well just up the road in Wilmington as well. Over the years, the children recruited to be location reporters have given us such gems as:

·         “The waves are actually breaking on the shore!!!!!” This from a young lady standing on Wrightsville Beach on a moderately overcast day with a light breeze ruffling her anorak hood.

·         “The water is right up to this wall!!!!” From a young man posted to Southport, who was apparently seeing the ocean for the first time in his life. The water comes right up to the seawall in Southport twice a day. We call it “high tide.”

·         “There’s actually sand on the streets here in Wrightsville Beach!!!!!” The young woman filing this exciting report after Floyd passed was displaying the media bias against the world south of New Hanover County. Down here in the boonies of Brunswick, more than a dozen houses had washed out to sea.

My own media bias being taxed to the limit by hundreds of reminders to lay in enough bottled water and canned goods for a month-long camping trip and/or to board up the windows and flee during the week before Irene blew by—do they really think we’re that stupid?—I composed a little ditty, which I append here for your amusement.

SOME HURRICANE DOGGEREL

Twas the week before Irene,

And from every TV

Came moaning and wailing

Of what we might see.

They rolled some old footage

Of Hazel and Fran,

Making all of us think
We should move to Iran.

Their eyes, how they glittered!

Though somber of voice,

“Stockpile batteries, water,

And canned goods of choice!

“Nail up that plywood!

Get all windows covered!

She’s coming! She’s coming!”

Beachside, cameras hovered.

They updated models

Computers kept spewing.

There’re awards in their futures

If viewers keep viewing.

Their eyes, wide and fevered,

Palms dripping with sweat,

Forecasters orgasmic,

As good as it gets.

*****

Twas the day after Irene,

We’d nothing to do

So we strolled to the ocean

To take in the view.

And what did our fully primed

Eyes hope to see?

Torn-off shingles! Hanging stair-steps!

Smashed flat-screen TVs!

Dune breaches! Erosion!

Roofs atilt in the break!

Fronts of homes missing

Showing stuff we could take.

The breeze’s light and playful,

The air crisp and clear;

As we got to the access

Our hearts filled with fear.

The water sun-sparkled

As waves hushed ashore,

We looked for destruction

Till our eyes got sore.

Irene had brushed by us,

We saw with relief.

But the tabloid reportage

Just beggared belief.

Yes, hurricanes are serious.

We know, tis the season.

Why’d the media treat us

Like we’ve all lost our reason?

Now I’m off to get the plants off the porch and perhaps rake up some of those leaves and twigs strewn about by The Great Storm.

Hope your hurricane was as non-eventful as ours was. Thanks for dropping by.

                                                                         Kathy

           

LOSING THE LAWN?



The scrofulous Fitzgerald lawn

             As regular readers already know, my coastal town of 6300 souls recently installed a $165 million (and counting) state-of-the-art sewer system in its bid to become the next Myrtle-Beach-like tourist mecca. As a consequence of our governing council’s edifice complex, water now costs residents three times as much to go out as it does to come in. Needless to say, the formerly grassy area at my house—can’t really call it a “lawn” because we never did much in the way of maintenance—has received no supplemental water throughout this droughty season. Although it looks scrofulous at the moment, I’ve already ordered the berry bushes and dwarf fruit trees to fill in some of the voids. New raised beds for sun-loving tomatoes and peppers are in the works. By spring, lawn will be all but gone.

           

            I’m of two minds about turf, though. The inputs required to maintain monocultural grassy swards waste water, employ noxious chemicals, add to air and noise pollution levels, squelch biodiversity, offer little to wildlife, and are a never-ending chore. On the other hand, lawns slow down and filter runoff, have a cooling effect, look pretty, and all that maintenance gives some people pleasure.

            There’s got to be a happy medium between the two.

            Tim and I both grew up in neighborhoods that looked very much like this suburban street. Tim’s dad loved his lawn, and he worked hard to keep it looking like velvet. He’d be out there most clement evenings, spreading fertilizers and weed-killers, digging out the odd rogue dandelion, waging war on moles, voles and insects, mowing, edging, patrolling, keeping the green perfect.

            My dad didn’t much care about lawns. He kept the weeds mowed (“It’s all green,” he’d tell my mom), but would rather spend his time planting nut trees, tending his vegetable garden and sitting in his little boat on the Poquoson River, fishing.

            A true child of my old man, Mr. Fitzgerald’s avocation was not what I’d call fun.

            Therein lies the crux of the matter. As Saxon Holt points out in his latest post at Gardening Gone Wild, gardening is supposed to be fun. Alter your perspective, he admonishes: you’re not “maintaining,” you’re “gardening.” Does tending a lawn make you happy? That’s gardening, not maintenance. Go for it. Although you may want to adjust the regimen so that you ratchet up your environmental responsibility a notch. Paul Tukey’s Organic Lawn Care Manual offers useful information in that regard (see Good Reads list at right). 

  



Are we having fun yet?

            On the other hand, do you regard taking care of the grass just one more job in an unending series of seasonal chores? If mollycoddling the lawn isn’t on your list of pleasant ways to spend time outdoors, then don’t do it.  

Tim and I fall into the latter camp most of the time. However, we know that grass can be an integral part of an overall design. Lawns offset planting areas in ways hardscapes can’t always pull off. Grass paths make for soft, cooling and serene spaces between beds, as we learned the hard way. (We surrounded our first gardens with brick chips—a nightmare to pull weeds from, a misery to kneel in, and the screaming orange color added 50 degrees to the backyard in summer. We dug it out and replaced it with grass after three years.) Grassed areas offer recreational opportunities, too. Nobody, for instance, enjoys a rousing round of croquet played on pavement. Plus, a lot of us just like having some lawn around: the texture and especially the smell of new-mown grass always remind me of being a kid during the summer.

             Conflicted? Go to LawnReform.org’s website. A coalition of writers and activists of both anti- and pro-lawn persuasions, they gently urge you think about the rationales underpinning our lawn fixations. They point readers toward organic turf care, low-maintenance grasses, water-wise management and plans for reducing or replacing all that grass. Evelyn Hadden, one of the founding members, has written a book entitled Shrink Your Lawn (see Good Reads), full of ideas for transitioning from cookie-cutter suburban-mindset grassiness.
                                                                                                             
              For a historical perspective on Americans and their relationships to their yards, you can’t do better than pick up a copy of From Yard to Garden: The Domestication of America’s Home Grounds (see Good Reads) by Christopher Grampp. Starting with the agrarian Founding Fathers and moving through industrialization and urbanization to the rise of suburbia, Grampp shows how people relate to the land around their homes. He’s not anti-lawn, which may be one reason his book isn’t more widely known. (Like in the art world, gardening elites fall into trendy traps too.) 

 Still, getting rid of all or part of your grass can open up a world of pushing-the-envelope possibilities for the adventurous. Rosalind Creasy’s classic Edible Landscaping: Now You Can Have Your Gorgeous Garden and Eat It Too (see Good Reads) gives lots of suggestions for turning your yard into an artful—and delicious—cornucopia. I’m rereading it at the moment.  



A claustrophobic-feeling
grassless garden

            Not all lawn-reduction projects are created equal, however. Some lawnless gardens feel claustrophobic to me, all encroaching vegetation, narrow paths, and airlessness. Some seem overly arid and barren—especially Southwestern-themed gardens located anywhere other than the Southwest. A cactus garden in a swamp jars the sensibilities, as do palms juxtaposed with deciduous trees.



A Fitzgerald-designed
grassless garden

            Ultimately, it comes down to individual taste—what you think looks nice, how hard you’re willing to work at it, and how much you enjoy the labor. Here’s a photo of one turf-free garden Tim and I designed and installed some years ago when it was just completed. This one is softened and shaped by the woods it backs up to, and has worked well over time.



See how the grass makes
this garden stand out?

            How much grass is too much grass? No one knows. Manicured or missing, the main thing is to make sure you’re having fun with whatever’s happening on your patch. Me? I’m planting fruits in the front yard.

Thanks for dropping by. Will wrap up August next time, if Irene doesn’t wash us away.

  

                                                                        Kathy

SOME DON'T LIKE IT HOT

            I regard my email inbox with the same jaundiced eye that used to be reserved exclusively for the telephone. As far as I’m concerned, these communication devices take up space in our house for my convenience, not anyone else’s. Over the years, I’ve perfected the selective deafness required to ignore phone summons (a trait inherited from my dad, the lone male in a six-person household, whose ability to tune out female voices was legendary). The insidious nature of internet technology is harder to circumvent. Email hooks me with written words. I’m the kind of person who reads everything: signs, labels, every word of anything I’m asked to sign. Ergo, it’s hard for me not to read something right in front of my face.

            Yes, there’s a point to subjecting you to yet another of my peculiarities. The emails I’m having a tough time deleting lately have to do with fruits for fall planting.

            Burpee’s started it. Cooks Garden and Gardens Alive! chimed in yesterday. It’s like they know my weaknesses and are out to make a few bucks off them. Opening these siren–song solicitations, however, led me down the unexpected path of discovering how many chilling hours the average Brunswick County winter is good for.

            What’s a chilling hour? you ask.

            A chilling hour is a 60-minute period wherein the temperature is 45°F or less. You add up all these hours between November and February, the result being a number that tells you how much cold weather you have.

            What does that mean for my garden? you persist.

USDA cold-hardiness zone map
for the Southeast

            Chilling hours are the basis for the USDA’s cold-hardiness zone map, a tool to help you decide what plants will most likely survive an average winter where you live. But many edibles and ornamentals also have chilling requirements that determine whether or not they will fruit or flower.

            In my neighborhood, for example, tulips, lilacs, rhododendrons, peonies and fritillaries cannot be counted on to produce the gorgeous blooms that are the reason we grow them in the first place. Why? Not enough chilling hours. We have the same problem with apples, raspberries and cherries. On the other hand, figs, pomegranates, okra and other native hibiscus (what? you didn’t know okra’s a hibiscus relative?) do well here because we don’t have too many chilling hours. Capisce? 

No peonies for me

            So anyway, I was drooling over the online offerings of berries and stone fruits when it occurred to me that I didn’t know how many chilling hours I can depend on from a regular Brunswick County winter. (It may surprise you to learn that I am not obsessive enough to track chilling hours on my own. Hourly temperature checks around the clock for 18 weeks are required: nobody likes me when I’m sleep-deprived.) Not having a suitable reference work to hand, I went net-surfing.

Minimum chilling hours
across the southeast

           What I found, after some considerable time wandering around in the ether, was this map, at AgroClimate: A Service of the Southeast Climate Consortium. It specifically refers to growing peaches with varying chill needs in South Carolina, but the broader information’s revealing. (What really struck me was that most of the United States has more than 1200 chilling hours per winter: the national map was mostly white. No wonder people are moving south in droves.)

            Searching for chilling-hour statistics segued into learning about heating degree days and cooling degree days. I’ve seen those abbreviations on the National Weather Service’s almanac pages for years, and vaguely knew what the letters stood for, but not what they meant.

            Which is…? you prompt.

Barrow, Alaska

            Heating degree days (HDDs) are a measure of demand for energy to heat buildings. You settle on a base outdoor temperature below which the house gets nippy so you turn on the heat. Most calculations use 65°F. So you average the actual high and low temperature of a day (adding the high and the low together and divide by two) and subtract the result from the base. For example, on January 13, 2011, Oak Island’s high was 41°; the low was 28°. (Brrrr.) The average of the two is 69, divided by two is 34.5; a base temp of 65 minus 34.5 = 30.5. That means Oak Island had 30.5 HDDs on January 13.

Miami Beach, Florida

            Cooling degree days (CDDs) are, as you probably already suspect, a measure of demand for energy to cool buildings. To figure these, you subtract the base from the average of the high and low temperatures of a day. To continue with the Oak Island example, on July 7, 2011, the high was 93° and the low, 79°. We add those numbers, getting 172, and divide by two for an average of 86. Subtracting our base from the average (86 – 65 = 21) gives us 21 CDDs for July 7.

            I hate math, you grumble. But I’m assuming there’s a payoff?

            Well, maybe. Mostly I just think this stuff is fun to know, and I do like math. I found a really cool (pun intended) website called Degree Days that’ll calculate the number of HDDs and CDDs of any location with a reporting weather station, which usually means a controlled airport. Then I compiled a little table, comparing the HDDs and CDDs of six representative cities.

                                     

CITY	HDD	CDD
Barrow, Alaska	19,900	1
Los Angeles, CA	2020	638
Miami, FL	234	4510
Montreal, Quebec	7570	616
New York, NY	5050	1392
Wilmington, NC	2634	2120

            Isn’t this neat?

            Payoff? you remind me.

Pink Lady apples: yes

            Well, you can monitor the efficiency of your heating and cooling systems by dividing the total number of HDDs or CDDs for the period covered by your monthly power/oil/gas bill into the total kilowatt hours/gallons/therms used. Establish a baseline, then look for discrepancies. Tim and I replaced our 13-year-old HVAC in June, so I compared the August bills from 2010 and 2011. In 2010, with the old heat pump, we slurped up 2.05 kilowatt hours per CDD. This year, we only used 1.61 KwH per CDD. Now, that’s efficiency! (For a more detailed explanation, read Jack Williams’ “Answers: Heating Degree Days” article linked here.)

Lapins cherries: no

             Oh, yes. To circle back to the beginning: based on all my new knowledge, I decided which fruits to order. Blackberries, yes. Raspberries, no. Southern highbush or rabbiteye blueberries, yes. Northern highbush, no. Pink Lady apples, a hot-climate cultivar from western Australia, yes. Lapins cherries, bred in Canada, no. Lilac, maybe. There’s a “new,” “heat-tolerant,” “reblooming" version out there called Bloomerang™ Purple Penda. I’ve tried all the rest of them—without success—over the years: might as well give this one a go. Will keep you posted.

Now all I have to do is find a place to plant them.

Thanks for dropping by. Stay cool. Or whatever.

                                                                        Kathy

Lilacs: maybe