BROOKINGS – There have been problems with trees locally, but it’s not what people think, said John Ball and Tanner Aiken.
Ball is a professor at South Dakota State University, an SDSU Extension forestry specialist, and South Dakota Department of Agriculture forest health specialist.
Aiken is co-owner of Glacial Lakes Tree Service and a project manager/horticulturist with SDSU.
Diane Fjerstad asked the Brookings City Council this week why all the pine trees were dying around town. She said it appeared to be a pretty large problem and asked if there had been a notice by the city to warn the public.
City Manager Paul Briseno said he’d have Dusty Rodiek, the director of the Parks, Recreation and Forestry department, contact her about her concerns.
“But no one’s noticed it, apparently?” Fjerstad asked.
“My pine trees look great,” Mayor Keith Corbett said.
Councilor Patty Bacon asked Fjerstad if there was a particular part of town where she was noticing the decline of the pines, because Bacon had not noticed a problem with the pines, just the old elm trees in her neighborhood.
Fjerstad said she’d noticed it all over town.
Councilor Ope Niemeyer said he had discussed the issue with Aiken, who has been treating trees, adding other companies do so, as well.
“There is something happening … There is awareness of it,” Niemeyer said.
Both Ball and Aiken said the main problem is not with pine trees, but with the spruce trees. It’s common for people to confuse the two, they said.
“We do have some poor looking pines due to diplodia tip blight, a fungal disease, but most of the poor looking evergreens in Brookings are Colorado blue spruce,” Ball said.
Aiken said he’s seeing some minor diseases in the pines and been treating them.
“I’ve seen things like Zimmerman pine moth, which is a native bug that attacks some of our non-native pine, like Austrian pine, Scotch pine,” Aiken said. “(Glacial Lakes has) done a fair amount of treatments around town.
“We do have some diseases … in pines, but they’re pretty minor compared to the decline we’re seeing with the spruce,” he added.
“We have lots of dying spruce in Brookings. They are suffering from a number of biotic agents, from cytospora canker to needle cast diseases,” Ball said.
Those diseases usually appear as the spruce ages, similar to how humans are more susceptible to disease as they age, Aiken said.
“We are seeing spruce trees in that 20-30 years of age start declining from different fungal diseases,” he said. “They hit a certain age, they lose a lot of vitality and so it’s a lot easier to succumb to these disease pressures.”
Old age is the problem, especially for the Colorado blue spruce, Ball said.
“The real problem is most of our spruce are old and the decline is due to their age. Colorado blue spruce, the most common evergreen in town, are not ‘happy’ in Brookings. Our summers are too warm and humid, so they age quicker than they do in their natural environment. Many look great for their first 20 to 30 years but the decline starts then and once the trees reach 50, most are either dead or in serious decline,” Ball said.
People might think it’s “epidemic proportions” but the answer is simple, according to Aiken.
“We’re seeing a lot of trees that were planted at the same time all reach the same age – the same 20 to 30 years old – all at relatively the same time and that’s what’s making this look pretty bad,” he said.
If you have spruce trees and want to keep them as healthy as you can, you have some options, Ball and Aiken said.
“You’re actually going to preventively treat your trees with growth regulators to help keep them healthy,” Aiken said.
“An application of Cambistat on a mature, but not yet declining, spruce can delay the decline. This application reduces shoot growth – so the tree becomes fuller – and increases root growth – important to improve the health of the tree. This has to be applied by a commercial applicator,” Ball said.
The growth regulators can help slow the disease down, but “they’re not 100% effective,” Aiken said.
“Really, once the disease has taken hold – either the needle cast or cytospora canker which are on the branches – once those have taken hold, it’s pretty tough to get back on top of them,” Aiken said.
Aiken said if you want healthy trees, start planning before you start planting.
First thing is be careful what evergreen tree you plant, he said.
Aiken said they don’t recommend people plant a spruce, but if you’re really set on it, there’s some precautions to take.
Instead of Colorado blue spruce, Aiken suggested Meyer spruce as a good alternative, but it’s difficult to find, he said. Ponderosa pine is still a decent choice, although it has some minor disease issues, Aiken said.
“A Siberian larch is really good, too, but it does lose its needles in the fall,” Aiken said, admitting that does defeat the purpose of getting an evergreen, “until you see the fall colors, then you go ‘holy cow, I have to have one.’ It’s a golden yellow; they’re really pretty.”
How you plant is as important as what you plant.
“Plant them so you’re going to have air flow between the trees when they’re mature,” Aiken said. “Because air flow is very important for managing fungal diseases.”
Good cultural practices make all the difference, he said.
“We like to keep a healthy tree healthy,” he said.
The top question Aiken gets these days is about the emerald ash borer and whether people should be treating their trees now.
“For injections, probably not recommended,” he said.
Emerald ash borer has been found in Sioux Falls this past year. Ball suspects the shiny green insect was there for a while before it was detected, and Aiken agrees.
“It hasn’t been detected (in Brookings) yet, but typically, it’s embedded in a community for three to five years before detection. So I’m not saying that it’s not in Brookings, but we haven’t detected it yet,” Aiken said.
Don’t panic, he recommended, and get answers from experts.
“Misinformation can be really dangerous and costly,” he added.
Contact Jodelle Greiner at [email protected]