Dennis O'Hara
Rose Garden
The location of Duluth’s Leif Erikson Rose Garden opens it to lake winds and challenges its gardeners.
With Lake Superior sparkling in the background, could there be a more beautiful setting for a public garden?
It’s no wonder more than 100,000 people visit Duluth’s Leif Erikson Rose Garden every summer, and more than 100 weddings are held on this site that displays more than 2,600 roses of 195 different varieties grown to perfection.
The garden is one of the top three or four rose gardens in the country, says Duluth City Gardener Tom Kasper. “When the roses are in bloom we see visitors from across the street to across the world. And so many of them marvel at the beauty, the quality and the picturesque setting afforded them in the garden. They are even more surprised when they learn about our cutting-edge program for caring for them. Much of the fertilizer used is organic, making the garden an example for gardeners that you can have a beautiful garden and still protect the environment.”
So perhaps there is no better place to seek advice about preparing your roses for a Northland winter than from the experts connected to Duluth’s Rose Garden.
Along with Tom, Assistant City Gardener Mary Tennis has been caring for the garden since 1994.
Preparation for winter in the garden begins in mid-August when Mary applies a foliar fertilizer. She stops using the special granular organic fertilizer that she tailored to feed the roses. This stops young shoots from developing just in time for cold snaps.
Mary’s special fertilizer was published in the American Rose Society’s magazine. It is composed of alfalfa meal, fishmeal, blood meal and soybean meal, a mixture applied each spring. For those who live near Duluth, the Lake Superior Rose Society sells 25-pound bags of the fertilizer each spring as a fundraiser.
“We also use nitrogen and a foliar feed with all the trace nutrients,” says Mary, “and enriching the soil with organic matter such as manure or compost is an important part of our program. If the soil is healthy, the roses will generally thrive.”
Konnie LeMay / Lake Superior Magazine
Rose Garden
Each late fall, many of the bushes are “tipped” and buried to protect them from the winter months. Volunteers and work crews tip them back up in the spring.
Then, toward the end of October, the physical work of preparing for winter begins. Often there are still 4,000 to 5,000 blooms on the plants, so people are encouraged to carry them home by the armfuls.
While in some areas “cones” are used to cover roses, those do not work as well in the Lake Superior climate. Instead, Mary’s work crew and volunteers employ the “Minnesota Tip” – a technique recommended for rose bushes surviving winter in gardening Zones 5 and below (which covers the Lake Superior region).
First you cut the rose bushes back to 18 inches.
Next, tie the canes (branches) into bundles with synthetic twine.
Dig a trench next to each plant, loosen the roots opposite the trench and lay each bush down, covering it with at least 3 inches of soil.
About mid-November – when the ground has frozen – the Rose Garden crews cover the beds with bags of leaves. This prepares the roses for the long winter’s nap, with Mary’s crew returning to remove the leaf bags from the buried roses in mid-April, then “untipping” the bushes the third or fourth week of that month after washing off the canes.
While it’s important to protect roses during the winter months, Duluth’s Rose Garden – just like other areas around Lake Superior – tests gardeners’ abilities.
Winds off the lake are one of the biggest challenges Mary faces with the beautifully placed Rose Garden. While the winds lessen moisture on the leaves that causes fungal diseases, strong blowing on the roses when they are developing new shoots can be a problem.
To prevent the canes from drying out while their feeder roots are developing, Mary and her crew spray the plants with Wilt Pruf as soon as they uncover them in the spring. Roses need at least six hours of sunlight a day, good drainage and consistent water.
One of the charms of the Leif Erikson Rose Garden is showing what’s possible in our zones.
A new bed containing 85 old garden roses and hardy shrub roses offers area gardeners a look at roses that they can grow without winter protection. Mary mounds soil over the shrub roses only for the first winter after they are planted.
“The old garden roses are generally one-time bloomers, and they bloom earlier than hybrid teas,” says Mary. “Their sizes and shapes vary greatly from small, compact shrubs to large, 8-feet-tall by 6-feet wide bushes with long, arching canes. Many are very fragrant.”
Kathy Ahlgren, co-founder of the Lake Superior Rose Society and consulting rosarian for the American Rose Society, switched from growing hybrid tea roses to old garden roses (those grown before 1867) and hardy shrub roses several years ago.
“I prefer the more graceful shape of the shrubs and old garden roses, and I think are more attractive with companion plants. I felt if I had to do the increased spraying and burying in the fall, I wasn’t growing the best plants for this area.”
When Kathy plants her roses in spring, she mixes two-thirds original soil with one-third composted manure and uses Mary’s special organic fertilizer. She follows the “3 Ds” of pruning, removing only dead, diseased or damaged canes. She does rejuvenation pruning after the roses are 4 to 5 years old, taking out 20 percent of the oldest canes each year.
Fall care for shrubs and old garden roses is minimal, Kathy says. As in the Rose Garden, she stops all fertilizing the first of August and allows rose hips to form. She ties up the long canes so strong winds don’t damage them through the winter.
As to bush choices, Kathy recommends Morden roses, which are bred in southern Manitoba, are hardy, have good resistance to disease and good floral quality.
Margaret A. Haapoja is a Minnesota Master Gardener and an award-winning freelance writer who gardens with her husband on Little Sand Lake south of Calumet, Minnesota.