On Tuesday, July 16, professional nurseryman/gardener and author Eric Bergeson of Fertile, MN visited Garretson to promote his newest book, Successful Gardening on the Northern Prairie. While the turnout was small, possibly due to the early weekday time of 4:30 pm, the audience thoroughly enjoyed his expertise.
“He knows a ton,” said Master Gardener Colleen Collier, who helped promote his visit to Garretson. The audience of approximately 12 women was able to glean plenty of information from him.
“Successful Gardening” is his seventh book; while he wrote weekly columns for area newspapers, this one is his first true “how to garden” book.
Bergeson grew up in the gardening business; he inherited Bergeson Nursery from his father and owned it for 17 years before selling to his brother so he could concentrate on writing and teaching. Bergeson’s grandfather, Melvin, started Bergeson Nursery in 1936.
Grandpa Melvin had an obsession with strawberries, Bergeson said.
While his brothers were out farming, eking out a life on the harsh northern prairie, Melvin spent hours learning how to cultivate and produce strawberries. One day, he discovered that sedge peat, an organic matter created by hundreds of years of composting cattails in semi-swampy areas, helped strawberries to grow by leaps and bounds.
“I once asked Grandma how she and Grandpa ever got to be married,” he said, insinuating that the two partners had nothing in common. “It took a while to figure out, but then I realized that her parents had acres and acres of sedge peat. The pieces came together after that.”
Sedge peat would then become his grandfather’s business, along with the strawberries. His family was usually able to harvest a bog for approximately 30-40 years until the DNR would declare the land as wetlands, and they’d move to another one. Eventually, they settled in Fertile, MN, which Bergeson says has endless peat.
“Using this pure makes for great planting,” he said. “If you can get the soil right, and get the fertilizer right, you can plant anything.”
Except palm trees. He says there’s always somebody trying to plant a southern-only plant up north. One does need to pay attention to the heartiness of the plant, and whether it’s intended as an annual or a perennial. “Annuals don’t care about winter, so you can play with those,” he said.
The soil of the northern prairie (of which Garretson is a part), according to Bergeson, is usually a perfect alkaline soil that helps plants grow easily. It rarely requires pH balancing beyond the addition of nitrogen to start planting, which can pull down the pH if it’s getting high. He says that’s important to take into account when shopping in nurseries, even local ones. The plant food and “Miracle Gro” they sell is often unnecessary. It can shoot salts way up and burn plants. What’s important is organic matter, but it needs to be very well composted, otherwise it leaches nutrients from the soil in order to help it break down.
He says that to replace oxygen, his father discovered that the best fertilizer to use is ammonium sulphate, which helps to lower pH and put nitrogen back into the soil. However, supply and demand is an issue, because most stores stock fertilizers that are best for “the rest of the U.S., not the Northern Prairie.” This is because most garden centers cater toward the clay-based and lime-based soil that is common throughout the rest of the U.S. “The northern prairie only has a fraction of the number of people elsewhere,” he said, “so the national gardening media doesn’t care about us.” This means most box stores and even local nurseries don’t stock fertilizer that is geared toward this type of soil, and if they do, it’s overpriced. In his view, the best thing to do is for communities to gather a group of 10-12 people who are willing to order a large batch, then put that order in with the nursery.
“It’s the same with native trees,” he said. “The trees in your local extension office are great. But they don’t stock them in nurseries because those aren’t the ones in demand.” He says for tree replacement, as the ash borer moves through, it’s important to have a mix of slow-growing and fast-growing trees.
“The slow-growing trees will have a firmer root base. Like burr oak, for example. But they’re really hard for nurseries to move, so they aren’t sold as much.” The fast-growing trees will fill out open areas quickly, but don’t last very long.
He also talked about how it’s important to water correctly. Often, people water too much but not enough. Meaning, if a soil is dry (which is a common occurrence in a hanging planter, for example), it’s important to water it twice: once to get the soil wet, and again 5-10 minutes later to soak the plant. “Too often, people only water once. The soil doesn’t retain that first watering, it just goes right through,” Bergeson said. The second watering is the one where the soil and organic matter holds moisture and benefits the roots.
He also noted that the best type of garden watering is a slow leak or a soaker hose that is forgotten about for 7-8 hours, once per week. Other types of watering patterns don’t go deep enough to make a difference, causing weaker root systems and wasting water.
The final pieces of advice presented dealt with container planting size, hydrangeas, and roses. He recommends for certain plants like petunias, to go with a larger container. “Petunias will pout for six weeks if they get even a little bit dry,” he said. “And then your summer is over when they finally look good again.” With a larger container, more moisture is retained, keeping the roots from drying out.
For hydrangeas, Bergeson bemoaned the fact that they’re used so little in the northern prairie.
“They love sedge peat,” he said. “They aren’t used enough around here. All they need is a little ammonia sulphate, and they’re beautiful. You’ve got to use the ones meant for zone 3-4, though.”
And for roses, feel free to plant them. “If they’re planted 8 inches deep, even zone 5 roses can survive here,” he said. They’re the only plant he recommends using “bad chemicals” on, to help prevent leaf rot or spotting, but emphasized, “don’t make tea from the rose hips if they are treated with a systemic spray.”
Bergeson’s latest book, “Successful Gardening on the Northern Prairie,” is available on his website at EricBergeson.com. Over 13,000 copies have been sold since its release in 2017.
