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

The area was formerly farmland, and Bork believes the farmhouse was built to take advantage of the swamp oak trees adjacent to her property, as the rest of the land was mostly prairie.

“The farm backed up to Purgatory Creek,” Bork said. “When we moved in, there was a windmill and a corn elevator, and we could hear the windmill.”

While the oak trees may have been important to early farmers because of the shade they provided for their farmhouses, they continue to play an important role in the Borks’ lives today and are a labor of love for three generations of the family.

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

Today, Bork’s grandchildren love to run up the hill as soon as they arrive to see if Gabriella, the tree fairy, has left them any money or bills in her special house built in one of the oak trees.

“These oaks were already here when we moved in, so I always thought they would stay here,” Bork said.

Unfortunately, Bork’s oaks, like many others in 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 do better after treatment in the fall.

According to Karli Wittner, director of Eden Prairie’s forestry and natural resources department, the oak trees have been severely damaged by the drought of the past three years.

“We see that piling up after three years,” Wittner said. “Now, after a wet summer, it’s kind of the other extreme. Many have been able to recover, but some have gone into what we call the ‘spiral of decline,’ where they have a lot of factors that make them more susceptible to disease or insect infestation.”

Erika Commers, Eden Prairie’s forestry and natural resources specialist, added, “The climate changes that we’ve experienced in the form of extreme saturation and drought seem to have had a greater impact on the oaks, particularly the swamp oaks, and also the older ones because they’re less vigorous and resilient. So we’ve noticed it across the country, especially in mature oaks.”

Arborist Rob Picha also sees first-hand the plight of many oak trees in the southwestern suburbs, where he focuses his practice.

“Oak wilt is a fungal disease that attacks oak trees, and with the drought, their immune systems are already compromised,” he said. “And then there’s a new borer called the two-striped chestnut borer that attacks oak trees when they’re already stressed, and it just devastates them. If you drive around, you see 100-year-old oak trees that are now half dead.”

At Staring Lake Park, where Wittner says “the majority of the park is oak,” she and Commers showed several suffering oaks. Although oak wilt, a frequently fatal disease, is present in the park, not all oaks are affected equally. And while the decline is likely primarily due to drought, many other factors may be contributing to the decline.

“Especially with an oak tree that is home to 500 different insects,” said Commers. “The situation is definitely complex and there are a multitude of problems, all caused by drought and general climate extremes. Too much rain has the same effects as drought. Every extreme affects the trees.”

Although the percentage of oak trees affected is currently small, this is more noticeable because the trees most affected tend to be very large, mature trees. Oak trees have long been considered a symbol of strength and endurance and can live up to 1,000 years.

“Because oaks are so long-lived, we notice even more when these ancient creatures disappear, and that’s sad,” Wittner said. “They are so big and majestic.”

“It’s always strange when things change and we don’t have answers,” Commers said. “When things change at the regional level and we see patterns of change, everyone in the entire forestry community across the state pays attention.”

Picha estimates that he “probably treated 20 to 25 oaks this spring. Big, mature oaks, 100 centimeters in diameter, beautiful shade trees.” Unfortunately, he says, “most people don’t even know about it.”

When he has to inform people about the condition of their oak trees, “they are devastated,” he says. Although people aren’t as surprised when they hear an ash tree needs to be cut down, “when I point out an oak tree nearby that’s dying off its tops, it’s a total shock and not good news. They have to pay for maintenance or to get rid of it.”

Although oak wilt can be treated if caught early, Picha said the best treatment is prevention. “Oak wilt is a fungal disease that can spread quickly in red oaks,” he said. “It can destroy them in a matter of months, about one summer.”

Picha, who grew up on his family’s Eden Prairie farm, spent his summers growing vegetables, doing landscaping, removing trees and pruning. “I’ve planted a lot of trees that have grown pretty big now. It’s fun to walk around and look at it,” he said. “Oak trees are my favorite trees personally. Just the way they look and everything about them.”

In addition to their stately beauty, oak trees are heroes of the ecosystem because they provide food and shelter for many animals. They are also beneficial to humans because they purify the air, stabilize the soil and provide shade.

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

According to Picha, “treating before you notice anything is the best thing you can do.” He recommends having an arborist come out about every two years to inspect the trees, or opting for a fungal treatment every spring. “Oaks are slow-growing and hardwood, so you want to prevent the problem in the first place,” he said. “It’s hard to reverse things.”

Wittner and Commers also recommend irrigating trees during drought periods.

“If it hasn’t rained for a week, especially after a long rainy season, it never hurts your trees to give them a good overnight watering once a week,” Commers said. “A slow, deep soak is most effective.”

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

Wittner says it’s best for homeowners to keep a close eye on their trees and watch for changes such as wilting leaves, dying branches or fungus, all of which can be an indication that something is wrong. Quick identification allows for more effective treatment.

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

City foresters encourage people to contact them if they notice anything unusual about one of their trees so they can be aware of potential future widespread problems. Because they care about all of the city’s trees, they are also happy to answer citizens’ questions about their trees and even offer advice. For tree treatment, they direct people to the website treesaregood.org, where they can find a certified arborist.

Looking ahead, “One way to keep the tree canopy resilient overall in Eden Prairie is to continue to plant new trees and also plant a diversity of trees. Eden Prairie has limited space for parks, so we really need homeowners to help us maintain our overall tree canopy,” Wittner said.

“Eden Prairie is unique in that the city’s leadership recognized the environment early on and the opportunity to protect it rather than just develop it,” Wittner continued. “Eden Prairie as a whole is a culture where you want to protect your trees and have an urban roof. That’s really special.”

After all, imagination and tree fairies always need places where they can unfold.