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FeedTough Love
These beauties can take whatever Mother Nature dishes out
By Bonnie Blodgett
Photo by Judy White / gardenphotos.com
Last weekend, I raked the last of the leaves off my garden beds and felt the usual rush of exhilaration to find evergreens (coral bells, lungworts, bergenias, and the like) fully intact and a few early hostas poking up out of the still-frozen earth. But did I remove winter mulch too early? Will those shiny leaves and brave new stems freeze and have to start over?
I also hauled my houseplants outside, again hoping to give the weather gods a wakeup call. A call to my gardening mentor, Marge Hols, saved me from losing all of them. “You did WHAT?” she hollered into the phone. (And Marge is not the hollering type.)
She reminded me that climate change doesn’t mean we now live in the tropics. It means our weather is getting more extreme. Yeah, I get that. At this moment in time, a drought seems highly unlikely, but who knows? Last summer began with record low rainfalls and ended with floods. Hence this month’s topic: How to find those all-around tough plants that can take anything Mother Nature dishes out.
Hardiness ratings don’t tell the whole story. Heat tolerance has a rating system now too, and when combined with hardiness, it can tell you a lot about a plant’s ability to roll with the punches. A Zone 3 Alberta spruce may live on indefinitely in the sub-arctic, but chances are it will look like the burning bush. Its tender needles are highly sensitive to sunscald and windburn. I consider it the inverse of tough.
Junipers have a well-deserved reputation for durability. They’re not only extremely hardy, but many can survive on very little moisture, which makes the ground-hugging types an excellent choice for covering erosion-prone slopes in full sun. Choose ‘Arcadia’, ‘Blue Star’, or ‘Calgary Carpet’—all are recommended for such challenging sites.
But it’s not enough to hone in on a genus or even a species. You want to identify the best cultivar. I rely on reputable plant-award programs for help weeding out the survivalists from the wimps. The Perennial Plant Association (PPA) Perennial Plant of the Year award is sponsored by a trade group whose members breed, grow, and sell plants. They honor proven winners that have been around long enough to demonstrate exceptional durability and vigor, as well as beauty. The PPA’s selection of Calamagrostis x acutiflora ‘Karl Foerster’ in 2001 sparked such a surge in the popularity of this tall and slender ornamental grass that it’s now at risk of becoming (reputedly) over-used. ‘Karl Foerster’ stands out because it stands up, and landscape architects can’t get enough of it.
Never mind that. I have tougher problems in my garden than fretting over whether a great cultivar is still on Garden Design magazine’s “Way Hot 100” list. I figure it’s my job to figure out how to combine it with plants in an original way.
This year’s PPA winner is a hardy geranium called ‘Rozanne’ that I’ve been wanting to grow for years. Its selection means I’ll be able to find it. PPA winners’ availability is preordained—which, almost as much as vigor and beauty, makes life easier for me, as well as all those busy professional landscapers who like plants they can get their hands on in sufficient quantities.
‘Rozanne’ also fills a void. The blue-flowered cranesbills I grow are leggy and needy plants, more trouble than they’re worth. ‘Rozanne’ has an appealing clumping habit in addition to masses of long-blooming flowers. PPA winners usually address this kind of aesthetic shortfall.
Probably the most highly regarded awards programs are sponsored by nonprofit organizations. Nebraska’s GreatPlants program, a joint effort of the Nebraska Nursery & Landscape Association and the Nebraska Statewide Arboretum, honors plants in several categories, including trees, grasses, and perennials. (For a complete list of award winners from 2008 and years past, visit http://arboretum.unl.edu/greatplants/index.html#releases).
One of this year’s perennial winners is Geum triflorum (prairie smoke), a Great Plains native with small purplish-red, nodding flowers in early spring that turn into the feathery silver and pink seedheads for which the plant is famous. The Nebraska State Arboretum describes the plant as “softly hairy”—like my husband—as well as “easy to grow in poor, dry soil”—like my garden. And get this: It’s hardy to Zone 3.
The 2008 award-winning grass is blue grama, a short native grass with “eyelash-like seedheads.” More drought-tolerant than buffalograss, it can be planted with wildflowers to create a short-grass prairie habitat. It can also be used to edge a mixed perennial border. You might even try it as an alternative to turf in high-traffic areas where it’s hot and dry. Or cold. It’s hardy to Zone 4.
Dianthus ‘Wink’, a 2008 GreatPlants release, is not native but fabulous in every other respect. A low groundcover with clear pink flowers, this dianthus is exceptionally drought and cold tolerant, and doesn’t die out in the center as others in its family do.
Check out the website to learn about other GreatPlant award winners. They’re all terrific—and I should know. I wrote the piece for Garden Design that’s quoted at the top of the GreatPlants website, calling its program “one of five awards program worth watching.” It just gets better.
Extreme Greens
Here are a few plants that can survive (nearly) everything Minnesota’s seasons throw at them.» Trees/Shrubs:
- Physocarpus opulifolius ‘Diablo’ (a native also called ninebark)
- Rhus ‘Tiger Eyes’ (a slower growing sumac)
- Amelanchier canadensis and A. alnifolia ‘Regent’
- ‘Summer Wine’ weigela
- Cotinus coggygria ‘Royal Purple’ (also called smoke bush)
- ‘Knock Out’ Rose (shrub rose)
- Origanum laevigatum ‘Herrenhausen’
- Paeonia lactiflora ‘Jan van Leeuwen’ and Baptisia australis
- Asarum canadense (a native also called Canadian wild ginger)
- Lobelia cardinalis
- Phlox ‘Volcano’
- Veronica spicata (alternative to purple loosestrife)
- Geranium Macrorrhizum ‘Variegatum’
- Eupatorium fistulosum ‘Gateway’
- Sesleria autumnalis (commonly known as autumn moor grass)
- Pulmonaria
- Veronicastrum virginicum ‘Rosea’ (a native also called Culver’s root)
- Salvia x sylvestris ‘May Night’
- Ruellia humilis (a native also called wild petunia)
- Sedum
Bonnie Blodgett publishes The Garden Letter and is writing a book about smell.
11 ISSUES (1 YEAR)
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