Keeping EP’s mighty oaks and fairy dreams alive and well

When Chere Bork and her husband built their Eden Prairie home in 1987, four majestic oak trees towered over the land, clinching their decision to buy that particular lot. Today, one of the oaks on Bork’s property is estimated to be 350 years old, with the others around 200 years old.

The area was previously farmland, and Bork said she believes the farmhouse was built to take advantage of the bur oak stand adjacent to her property since the rest of the land was mostly prairie.

“The farm went all the way to Purgatory Creek,” Bork said. “When we moved in, there was a windmill and a corn crib, and we could hear the windmill.” 

While perhaps important to the early farmers for the shade they brought to their farmhouse, the oaks continue to be significant in the lives of the Borks, with memories for three generations of the family.

Bork recalled her son’s pretend police station in the treehouse. “The police chief from Chaska came to visit him and sat at his little table with him,” she said. “Then he gave him a police chief hat that we still have.” 

Today, Bork’s grandchildren love to run up the hill immediately when they arrive to see if Gabriella, the tree fairy, has left them any money or notes in her custom-built home in one of the oaks.

“Those oaks were here when we moved in, so I’ve always thought they would always be here,” said Bork.

Unfortunately, Bork’s oaks, along with many throughout Eden Prairie and the rest of Minnesota, are in danger. The oldest, “Gabriella’s tree,” as the family calls it, will have to be removed. They hope the others will fare better after receiving treatment this fall.

According to Karli Wittner, Eden Prairie’s forestry and natural resources supervisor, the last three years of drought have caused oaks to become very stressed.

“We are seeing the accumulation of that happening after three years,” Wittner said. “Now, with a wet summer, it’s kind of another extreme. A lot have been able to recover, but some have started down what we call the ‘spiral of decline,’ where they have a lot of compounding factors that are making them more susceptible to illness or infestation by insects.”

Erika Commers, Eden Prairie forestry and natural resources specialist, added, “The climate changes we’ve experienced in extremes of saturation and drought seems to have had more of an effect on the oaks, particularly bur oaks, and also the older ones, because they have less vigor and resilience. So we’ve been noticing it statewide, especially for mature oak trees.” 

Arborist Rob Picha also sees firsthand the plight of many oaks in the southwest suburbs, where he focuses his business.

“Oak wilt is a fungal disease that gets the oaks, and with the drought, their immune system is already struggling,” he said. “And also a new borer called the twolined  chestnut borer gets the oaks when they are already stressed, and it just devastates them. You can drive around and see 100-year-old oaks that are half dead now.”

At Staring Lake Park, where Wittner says “the vast majority of the park is oak trees,” she and Commers pointed out several suffering oaks. Though oak wilt, a frequently fatal illness, is present in the park, not all of the oaks are stressed equally. And though probably mostly drought-induced, many other factors can contribute to the decline.

“Especially with an oak that services 500 different insects.” Commers said, “the situation is definitely complex and there are a host of issues that are all spawned by drought and general climate extremes. Too much rain has the same effects as drought. Any extreme will have an affect on the trees.” 

Though the overall percentage of oaks affected is small right now, it is more noticeable because the ones most affected tend to be the very large, mature trees. Long a symbol of strength and endurance, oaks can live up to 1,000 years.

“Because oaks are so long-lived, it is more noticeable when we see these ancient beings declining, and it is sad,” Wittner said. “They are so big and majestic.”

“It is always a curiosity when things change and we don’t have answers,” Commers said. “When things change regionally and we notice patterns of change, everyone pays attention in the whole forestry community across the state.”

Picha estimates he treated “probably 20 to 25 oaks this spring. Big, mature oak trees, 40 inches in diameter, beautiful shade trees.” Unfortunately, he said, “Most people don’t even know about this.” 

When he does have to inform people about the plight of their oak trees, “people are devastated,” he said. Though people are not as surprised to hear about an ash tree needing removal, “when I point out a nearby oak tree with some tips dying back, it’s just a complete shock and not good news. They have to pay to maintain it or pay to get rid of it.”

Though oak wilt can be treated if caught early, said Picha, the best treatment is prevention. “Oak wilt is a fungal disease, and it can move fast in red oaks,” he said. “It can take them down in a few months, like a summer.”

Picha, who grew up on his family’s Eden Prairie farm, spent his summers growing vegetables as well as doing landscaping, tree removal and pruning. “I planted a lot of trees that have now grown quite large. So it is fun to go around seeing that,” he said. “Oaks are personally my favorite tree. Just the look of them, and everything about them.”

In addition to their stately beauty, oak trees are heroes in the ecosystem, providing food and shelter for many animals. They also benefit people by cleaning the air, stabilizing soil and providing shade. 

Picha said he hopes to “make people aware so they can treat their oaks before they are gone. My kids are in elementary school, and most kids their age, I bet, don’t know what an elm tree is, and I’d hate that to happen to oak trees. We don’t want them to go. They are beautiful, and you simply can’t replace a 150-year-old tree.”

According to Picha, “Treating before you see anything is the best thing you can do.” He recommends having an arborist come check out trees routinely every two years or so or opt for a fungal treatment every spring. “Oaks are slow-growing and hardwood, so you want to keep it out before it starts,” he said. “It’s hard to turn things around.” 

Wittner and Commers also recommend making sure that trees get watered during a drought.

“If we don’t get any rain in one week and especially after longer, it never hurts your trees to give them a good overnight soaking once a week,” Commers said. “A slow, deep soak is the most beneficial.”

Mulching the root zone under a tree also keeps it cool, provides nutrients and keeps moisture in the soil. “That and water during drought are really all trees need,” Commers said.

According to Wittner, the best thing homeowners can do is to keep a close eye on their trees and notice any changes, such as wilting leaves, dying branches or mushrooms, which all might indicate something is wrong. Quick identification allows for more effective treatment.

“If a tree is confirmed to have oak wilt, we recommend removing the tree to keep it from spreading,” Wittner said. “It is best to do this in the fall when the bark beetle is not present.” She also asks that homeowners have their arborist contact the city if oak wilt is found so neighbors can be notified.

The city foresters encourage people to contact them if they see anything unusual in any of their trees so that they can be aware of any potential future widespread problems. Passionate about all trees in the city, they are also eager to answer citizens’ questions about their trees and will even give advice. For the treatment of trees, they point people to the website treesaregood.org to locate a certified arborist.

For the future, “A way to keep the overall tree canopy in Eden Prairie resilient is to continue to plant new trees, and also plant a diversity of trees. Eden Prairie has limited park space, so we definitely need homeowners to help maintain our overall tree canopy,” said Wittner.

“Eden Prairie is unique in the sense that early on, city leadership saw the environment and the opportunity to protect rather than just develop,” Wittner continued. “Eden Prairie as a whole has a culture of wanting to protect their trees and have an urban canopy. It’s really special.”

After all, imaginations and tree fairies will always need places to flourish.