Pros weigh in on the best plants and gardening practices for our changing climate.
Extreme Gardening, that’s the name of the reality TV show someone really ought to make about what it’s like to be a northern gardener. We’re already well known for our ability to cope with short growing seasons while making sensible, hardy plant choices and coping with dreadful-sounding issues like frost heave and snow mold. Now, climate trends indicate that we must add excessive heat, humidity, drought and torrential “rain events” to our list of things to think about before putting trowel to dirt. Surely all of that adds up to enough adversity, struggle and tears to make a successful show, right?
As you no doubt have noticed, our climate is changing. In January, the U.S. National Oceanic and Atmospheric Administration announced that 2012 was the world’s 10th warmest year since 1880. Closer to home, 2012 was the warmest on record for the United States and the third warmest for Minnesota. But increasing average temperatures are not the only climate trend affecting our region. According to University of Minnesota Climatologist Mark Seeley, the average number of days with a high dew point in also increasing, and we are also experiencing changes in the amount and type of rainfall we get.
Annual precipitation has increased over the last several decades and is expected to continue to do so. Heavy rain that sometimes leads to flooding is becoming more common. Yet between these events, we are experiencing long periods of drought. Complicating matters further is the rate at which changes are happening, Seeley says. Because it is possible temperatures may rise faster than we, or nature, can adapt.Read More»
Who among us has not encountered at least one person (not always a gardener) who wags a judging finger when we admit our gardens include both native and non-native (also called exotic) plants? This natives-only stance is not only annoying, it’s also wrong-headed.
What’s the difference between a native and non-native plant? Plants that are native to North America have evolved and grown over thousands of years in a specific region before European settlement. Non-native or “exotic” plants, on the other hand, have been introduced in one way or another to an area in which they did not naturally grow.
Walk through any garden center, and while you may see a few native plants, what you’ll mostly encounter are exotics that have been bred and cultivated to offer benefits like bigger or longer-lasting blooms, disease resistance, or standout color.
Many gardeners, including me, love non-native plants because of the diversity they bring to the garden. This doesn’t mean we exclude natives, but we do have a mix of plants, and maybe even a preponderance of non-natives at home. As interest in natives has grown in recent years, so has their availability, as well as the debate over which plants are the best choice for home gardens. This debate is more complex than it seems, with some of the arguments breaking down as follows:
- Native plants are more pest and disease resistant than exotics. This is true in the sense that native plants are better able to withstand attacks from native pests and pathogens. But they don’t fare any better than exotics when faced with terrors like emerald ash borer, Dutch elm disease, Asian longhorned beetle, and white pine blister rust.
- Native plants are more drought resistant, so they can be grown more sustainably than non-native plants. This is true when natives are planted in places that offer the conditions they need to thrive. If you’ve got the perfect spot for a native prairie garden, by all means, plant one. But plant a native sugar maple in a sandy spot and it won’t be around to enjoy for long, since it needs loamy clay soil.
- Native plants offer better habitat and sustenance for insects, birds, butterflies, and wildlife. Again, there is truth here. Over time, all of these creatures have adapted to use what native plants offer. This discounts the fact, though, that many non-native species offer the same bounty, cover, and protection. What is truly at issue, some ornithologists say, is whether more and more birds that used to migrate are now sticking around to snack on the offerings of non-native plants when, sadly, some of these plants don’t offer seeds and berries with enough fats and nutrients to sustain birds through the winter. The birds may eat heartily, but it won’t be enough to keep them going through the long, harsh months so they don’t make it until spring.
- Non-native plants are invasive. People often lump non-native species in with invasive plants that take over landscapes, destroying ecosystems and choking out native plants. In truth, only a small number of non-native species are invasive—think kudzu, which is taking over the south.
Rather than taking sides on this debate, it seems more prudent to accept that both native and non-native plants have characteristics that endear and alienate gardeners. Though it can’t be qualified with research or backed up by studies, one of the best plain-and-simple reasons gardeners include non-natives in their landscapes is because they like them. Gardeners who limit themselves to natives miss out on the benefits of centuries of plant cultivation and innovation. Plants like gardenia, evergreen azaleas, Japanese maples, and Norway spruce are well-behaved, non-native species that look great in the garden and perform well in the right circumstances.
Of course, no gardener should knowingly plant an invasive species. Before adding something new to your garden, check with your local extension service to get a list of plants considered to be invasive in your area. You’ll find a list of extension services here: http://www.nifa.usda.gov/Extension/index.html. If you don’t have an extension service, check the Nature Conservancy’s Web site for detailed information on invasive plants: http://www.nature.org/initiatives/invasivespecies
I saw my first butterfly of the season the other day. I am but a rookie lepidopterist, so I don’t know what kind it was. All I saw was a streak of black, not nearly enough to be of help when looking it up in my field guide. As it swooped over my brown, sleeping garden, I worried about what in the world it would find to eat in these early days of spring. What was it doing here so soon?
The only thing I’m sure of is that it wasn’t one of our Eastern black swallowtails. It’s wings didn’t have the right yellow spots and blue patches. I say “our” swallowtails because for the last two summers my husband, Mike, and I have tried raising swallowtails on our front porch. We got the idea, or I should say I got the idea and my ever-patient husband went along with it, from a man named Jim.Read More»