What’s Blooming: Arb Edition

The Bright Side of the Blizzard

According to weather guru Paul Douglas, the blizzard that paralyzed the southern half of Minnesota and Wisconsin yesterday dumped 11.5 inches of snow on Northfield by 5 p.m. Saturday. My hunch (and my sore back!) suggest it might have been a bit more than that, or at least, we had enough drifting to make it feel like a lot more than that. But, there is a definite bright side to this blizzard. The plants — especially the USDA zone 5 butterfly bush that I’m hoping to get through the winter — are well insulated.

Snow serves the same purpose as mulch, only it removes itself in the spring. Once the ground is frozen (no problem here!) snow cover keeps temperatures consistent, so rather than thawing on warmer days and then re-freezing on colder ones, the plants will stay consistently cool and dormant through the winter. The chances of plants heaving out of the ground in thaw-freeze cycles are also reduced.

Because an earlier effort to growing butterfly bush did not work out, I planted two bushes in pots last spring and one in the ground near the house. They grew well and all of the plants flowered, but I’m hoping to help them get bigger. I fell in love with the large butterfly bushes I saw on garden tours in Buffalo, N.Y., last summer. The two pots are in the garage and, I hope, will survive the winter well there. The one in the ground is — thanks to the blizzard — under 2-1/2 to 3 feet of snow.

Only time will tell how this winter turns out, but for now, my plants are cozy under a very thick blanket of snow.

Fall Color Combos

This past weekend, I drove from Northfield to Chicago and back to visit my college-age daughter. It was a lovely trip, and the colors were vibrant throughout Minnesota, Wisconsin and in Chicago itself. On the way home, I stopped at the Rotary Botanical Gardens, one of the loveliest small botanical gardens in the Midwest. It’s in Janesville, Wisconsin, about five minutes off of I-90.

While walking through the gardens, which include an elegant Italian formal garden — which really reminded me of the one I’d visited in Rome this spring — a large pond with plantings around it and a number of beds featuring All-America Selections, I was struck by how well the gardeners here combined plants for fall beauty. This combination of several ‘Autumn Brilliance’ seviceberries near the Leonard Messel Magnolia was especially striking. (Unfortunately, my photo does not do it justice.) Interestingly, both of these plants are also vibrant in the spring, with early flowers and have distinct shapes, making them year-round beauties and a dynamite combination.

Flexibility

I’m continually amazed at what plants will do to survive. Recently, while thinning out some overgrown red-twig dogwood, I came across this branch. The canes of red twig dogwood are fairly soft when they form and the bush grows essentially as a thicket, with branches on top of each other and sometimes criss-crossing each other, or as in this case, just making a nice U-turn to go around each other. We should all be so flexible.

Hedging

Courtesy of Jung Seeds
Courtesy of Jung Seeds

A second part of our recent spruce-up was the removal of some old alpine currant shrubs that were dying. The shrubs formed a hedge around an area below our back deck, an area that I use mostly for storage of garden equipment. Not wanting to leave this exposed, I planted it this past weekend with nine plants of hedge cotoneaster (Cotoneaster lucidus), a plant that will grow about 4 feet wide and up to 8 feet tall. We’ll probably keep ours around 5 to 6 feet tall by shaving the tops. The cotoneaster should be an improvement over alpine currant for two reasons. First, it is less prone to disease and general keeling over. Second, has a blue berry that birds love, so it should be more attractive to wildlife. It also has a pretty reddish fall color. Right now, my hedge looks skimpy, but the photo at left is what it should look like in a year or two.

White in the Garden

IMG_6354In clothing and home decor, I avoid white due to my unfortunate tendency to spill coffee. But in the garden, judicious use of white is striking and it often gives a focal point to the garden. Recently, I’ve been enjoying several white patches. In back, these lilies (Lilium ‘Casa Blanca’), which I bought at the MSHS booth at the St. Paul Home and Patio Show this winter,  just started blooming. They are later blooming than other lilies, which may be because the spot in which I’ve planted them is too shady. I will move them this fall into a sunnier spot and remember to stake them next year. These are tall and striking, a real eye-catcher in an otherwise green part of the garden.

IMG_6359Near the lily is this new Annabelle hydrangea bush I planted this spring. Here’s a case of putting the right plant in the right place. Ever since it was planted in this somewhat shady spot, it has looked healthy and happy, and for the past few weeks, it’s been putting out bunches of white blooms. Annabelle is an old-fashioned hydrangea and will get 5 feet tall and wide. It makes a lovely hedge and is a reliable bloomer as far north as USDA Zone 3.

IMG_6365Finally, in the front-door garden, I have white sweet alysum. I’ve had poor luck with alysum in the past, but this year’s relatively cool conditions have been perfect for it. The white color contrasts well with the deep purple of these Wave petunias and the sunny yellow of the coreopsis planted near it.

Some gardeners choose to isolate white in one part of the garden and this can be beautiful, especially at night. If you’d like to try a white garden, check out this article on principles of designing with white.

Butterfly Bush, R.I.P.

I could have titled this post “I pushed the zone and the zone pushed back.” Last spring, filled with thoughts of permanently warm and wimpy winters, I planted a butterfly bush (Buddleia ‘Nanho Purple’). It was supposed to grow up to 6 feet tall and be covered with long clusters of purple blooms from August through September. (This image is from the Missouri Botanical Garden.) The bush seemed to do well, growing to about 3 feet in height with several nice blooms last fall. Butterfly bush is generally a Zone 5 and south plant and grows very large in some climates. Alas, Minnesota is still Zone 4, as this past winter proved. I’ve been watching the bush’s corpse in hopes of seeing some signs of life. None so far; none expected.

This incident drives home advice I heard from a horticulturist about planting for climate change. “Push the zone, if you want,” she said, “but don’t plant anything you can’t afford to lose.”

It also reminds me how grateful northern gardeners should be for the research that has been conducted over the years at places like the University of Minnesota and North Dakota State University. Research has expanded the growing options for gardeners in the north with everything from new magnolias to a wide range of shrubs to better apples. Plant breeding is a long, arduous and often frustrating process. Last summer, I had a chance to visit Harold Pellett (left), a retired U of M researcher and director of the Landscape Plant Development Center in Mound. Pellett, who during his 30-year career at the U helped develop 25 new varieties of shrubs including the Lights series of azaleas, founded the center to continue his work creating plants for the North. The center has already introduced a new ninebark, Center Glow™ ninebark, and a new non-climbing clematis, Center Star™ clematis. Pellett and his fellow researchers, who are based in Oregon, Russia, and lots of places in between, are working on several new varieties of woody plants, including a hardier butterfly bush.

“Will it be hardy enough to be reliable in Minnesota?” I asked him last summer. Pellett gave me one of those gentle, knowing looks that seemed to say, dream on, sister. “More like Iowa,” he said.