Rites of spring: Tree trimming and planting


Notice dramatic white scars on trees where major limbs used to be?

Minneapolis Park Board Forestry crews were out in force in the last couple of weeks, have now wrapped up spring tree-trimming work and are on to planting new trees, especially bare-root stock, throughout the city starting in North Minneapolis.

Workers in the field explained, and head forester Ralph Sievert confirmed, what the crews were doing with the tree trimming. In general, they trim so that as a tree grows, its limbs will be higher than 14 feet off the ground on the curb side so as to avoid truck collisions, seven feet on the sidewalk side.

A major limb might be taken off if it’s one of multiple leaders, or if the tree is in danger of splitting in half. Many trees have been trimmed already in years past—not necessarily well—by the power utility to avoid growing into the lines. A lot of the replacement tree stock in the 1970s was placed anticipating that the city would be putting utilities underground by 2000, which, for lack of money, never happened, Sievert said.

“Many of these trees aren’t going to be around long,” said one worker. The tree variety used to replace diseased elms on block after block, the green ash, is now in danger of fatal emerald ash borer infestation. It’s just a matter of time, he said.

Gary Myhre, foreman for the crews who work in Northeast, said they would be installing bare-root trees in Northeast on Monday and Tuesday, April 16 and 17, then hopping over to help with the North Minneapolis planting until other types of trees arrive and they can return to Northeast to plant them. Crews from around the city will be juggling their work in similar fashion, all helping to plant the 3,100 trees planned for the North Side, out of 6,000 citywide.

“We accept trees from out of state, even New York. They’ll come in throughout the month, so of the 297 trees planned for Northeast, probably 97 of them are not even in yet,” Myhre said.

In replacing trees today, foresters still strive for some continuity in species, but introduce diversity on every block. Whereas you used to have, say, a hackberry block or a linden block, Sievert said, you might now see several of one variety in a row, but then a switch to another, or more, different varieties all within the same block. This reduces the likelihood of losing an entire block of trees, as pests tend to be species-specific.

On the first North Minneapolis block to get trees on a frigid April 9, the first few placed were bare-root Accolade elms, disease resistant. New species residents will be seeing on their boulevards include Kentucky coffee, river birch, buckeye, bicolor oak and alder.

Will trees go right back in where the tornado-downed trees were? Often, yes, said Sievert, especially where the sidewalk has been altered to accommodate tree roots, otherwise the city will condemn the sidewalk. “We’re grinding deeper,” Sievert said, “usually we would go down eight inches, now we’re going down 18, and it’s all new dirt,” which will help the new trees get established. In the past, the city would not re-plant trees until roots had a chance to rot away.

Tree locations have been marked with a white “T” on the curb. Myhre said in Northeast they’re replacing any boulevard trees that died last year that were under six inches in diameter, plus requests from homeowners. Will that reforest all of Northeast? “Not by a long shot,” Myhre said. “Not everyone gets the message that they can call. We honor requests because then we know the tree will be taken care of. When we plant, we water two times and then it’s up to the homeowner. We’ll sometimes plant by an industrial building but then have to keep them on a summer water list, and with the reduction in force, I can’t get over-committed.”

At the ceremonial tree-planting at 14th and Upton avenues N, Third Ward Minneapolis City Council Member Diane Hofstede reminded people that the trees are going to need water. A forestry news release came out soon after, suggesting that homeowners start watering already.

Warm weather helped crews make quick work of trimming in the absence of snow obstacles. Typically they would switch to planting in late April, “but the nurseries started digging up trees quicker,” so the foresters had to start accepting delivery earlier. After bare-root trees are placed, container trees and stock with root balls in burlap are next. All planting will be done by June 1, foresters estimate.

When will they be grinding out old stumps? That’s a separate contractor, one worker said, not the forestry staff.

More information on trees is at minneapolisparks.org under news and events.