Even though I’ve given up making New Year’s resolutions, I get reflective at this time of year. The turning of the calendar might have something to do with this mood, but probably it also means that daylight is short, the temperature is cold and I have too much time to think.

A question that keeps coming my way is how far gardeners should go in planting native species. I think every yard should include some natives. But must all of the plants in your garden be natives? And must the natives be seed-grown species plants like those found in the wild, or can they be cultivars of natives, selected for prettier flowers or bigger fruits and produced by tissue culture rather than grown from seed?

If doing what is best for the environment is foremost to you, the answer is clear: Grow seed-grown natives in the soil that existed in your garden before your home was even built. You won’t be adding fertilizer and other soil amendments, and the plants will feed native insects, birds and other wildlife. It sounds like paradise.

The result may not make you happy, though.

Jake Pierson of Pierson’s Nursery in Dayton, a wholesale business that supplies most Maine nurseries and nurseries in other parts of the country, says that his family’s company sells the species version of many natives.

“The problem is that after a couple of years, the species plant does not meet the customer’s expectations,” Pierson said. Although they like the idea of having the plant that grows in the wild, when it comes down to it, they don’t like the way the wild plant looks in their urban or suburban garden.

Take, for example, the arrowwood viburnum, Viburnum dentatum. It has glossy green leaves and blue fruit. The species gets 12 feet tall, while the cultivars (or nativars if you like that term) like “Blue Muffin” are much shorter, meaning they fit better, without pruning, in many household gardens.

PLANT FOOD HANGOVER

I heard the idea that home-garden soil is too rich for native plants at a wildflower symposium the Garden Club Federation of Maine conducted in September. Barbara Murphy, a retired Cooperative Extension educator and now co-owner of a native plant nursery in South Paris, said native plants aren’t accustomed to soil with added compost and fertilizer or the regular watering that they will get in most home gardens. Imagine living on a diet of rich French pastry – it’s something like that for them.

The leaner, unamended soil in your garden will suit the native plants better, but that’s just one benefit. If you don’t amend your soil and water regularly, you save yourself work and money. You are also a bona fide environmental champ, as fertilizer runoff is a major pollutant of lakes, streams and the ocean – with phosphorous and nitrogen contributing the algae blooms that deplete oxygen in the water and harm fish.

But when your house, with its basement, was built, the digging alone changed the native soil. While the change may lesson over time, even if your house is a few hundreds year old, this still holds true. If you are a purist, you’ll be limited to the plants that like the type of soil you have in the areas that were undisturbed during construction. If you have elderberry on the property, you could grow other upland plants like the arrowwood viburnum, for instance, Pierson noted, but plants that require moisture, like the winterberry, probably won’t thrive.

Even native species plants you get from a nursery may need pampering once you get them home, Pierson added. That is because all plants, whether native or exotic, get pampered at the nursery, with daily watering and occasional fertilization. Once they are in your yard, you’ll have to wean them off that coddling slowly.

GREAT BACKSTORY

Another thing I am thinking about as the year draws to a close is the debate over what a native is, and my reflection is prompted in part by a purchase I made in the fall.

While at Allen, Sterling & Lothrop in Falmouth, I happened to see a Franklin plant, Franklinia alatamaha. This small tree was first chronicled in Georgia, in 1765, by John Bartram, Royal Botanist for North America and the nurseryman who provided plants to such Founding Fathers as George Washington and Thomas Jefferson.

William Bartram, John’s son, brought seeds to Philadelphia in 1773 and grew the tree, which he named after Benjamin Franklin. Franklinia was rare even then and today is extinct in the wild, having last been chronicled in the wild in 1803.

I bought the tree, not because it will help support native wildlife, but because I liked its story and thought it would look good in our garden – it has glossy leaves and white flowers with a yellow center. It blooms in late summer, when there are fewer blooms than in the spring. Also, the nursery was having a 40-percent-off sale (I am a Maine native, after all).

It was an impulse purchase – I wanted to own a little piece of history.

YOU’RE THE BOSS

Which brings me back to my original question: How far should we go in planting natives rather than traditional ornamental garden plants? The answer is: It’s up to you. But here are some things to consider:

The minimum requirement for every gardener is: do no harm. Do not plant – or even allow plants to grow – that are invasive and will out-compete natives and harm habitat. If the home you bought came with invasive plants in the garden, you are responsible to keep those invasives, at the very least, under control. I’d like to suggest removing them entirely, but in my own experience, that’s a lengthy process that demands vigilance each and every growing season.

The next step is to plant an array of natives that will provide flowers for pollinators from spring to fall as well as food for other wildlife all year round.

Few people are likely to pull out their peonies, roses and rhododendrons and replace them all with native plants. But when a plant dies or you’ve a hankering to buy a plant for some other reason – say it’s on sale and has a great back story, check first to see if there’s a native that can play the same role in your garden. If it can, buy it.

If you’re starting from scratch, buy as many natives as you can. But if you can’t resist a non-native, give yourself permission. It will harm the world less than a hot tub or a giant plastic shed in your backyard.

Tom Atwell is a is a freelance writer gardening in Cape Elizabeth. He can be contacted at 767-2297 or at: tomatwell@me.com.