Arbor Day 2017

Sowing the seeds of our Edina landscape.

Arbor Day has roots entrenched into history. The idea of planting and celebrating trees goes back centuries to Spain and migrated to the U.S. nearly 150 years ago. Forests were planted in Nebraska and the idea spread nationwide. The last Friday in April marks the observance of Arbor Day in Minnesota, and Edina is no exception. The city selects a different park every year to plant trees in observance of the holiday. By doing so, Edina helps to maintain its 19-year designation as a Tree City.

Edina is one of 97 Tree Cities in Minnesota. To maintain status as a Tree City, Edina is required to have a tree department and forester, tree-care ordinance guidelines, a budget allocation of $2 per capita on trees and an official Arbor Day observance with a proclamation.

Edina’s Arbor Day celebration will take place at Sherwood Park by Grandview Square at 10 a.m. on April 28. New trees will replace five ash trees removed last year, in preparation for the threat of emerald ash borer, according to city forester Luther Overholt.

Arbor Day is a great time to witness the best practices of tree planting first hand. Because more goes into proper tree care than meets the eye. Overholt will hand-pick the trees for this year’s planting. A two-man crew will help him get the young trees into the ground, and the public is welcome to attend the ceremony. Why not join in the Arbor Day fun? Planting trees makes a difference for generations to come.

Why all the fuss about trees? Trees are an important resource in Minnesota for lumber, recreation and more. For homeowners, trees provide intrinsic value for water, energy and carbon savings, and trees are cornerstones of the urban landscape. Besides their stately beauty, trees purify the air, provide spring and fall color, shade, privacy and wildlife habitat. Trees define the living structure of a city with a canopy of leaves and needles.

The city considers the effect of trees on residential construction projects. A preservation ordinance enacted for new homes requires visual inspections, tree fencing and escrow holds on landscape planning. Overholt is responsible for the tree inspections that are geared toward maintaining tree density.

The life of a tree is far from easy. Even trees have enemies. The bright jewel-tones of the emerald ash borer mask its lethal force. While newer ash varieties are resistant to the pest, older untreated ash trees will likely succumb. The city treats some ash trees in prime locations but most are removed to prevent infestation and other problems down the road. The city has done preemptive removal of many trees already, with plans to remove at least 250 ash trees, says Overholt. “Ash trees along the boulevard can be potentially hazardous. Once the trees get emerald ash borer, they lose all integrity.” A recent survey revealed 1,549 ash trees in Edina, but there are likely more.

Overholt’s city forestry duties extend year-round. Edina has 41 parks and a near equal number of other green areas to maintain. Summer is crunch time, when trees are leafed out and growing. Still, “fall is the best time to plant—[you] don’t have to be babying them.” Winter snow pack can provide water into the spring but weather is a variable. New trees require two to three years of maintenance, including ongoing watering, says Overholt. Tree planting involves a long-term commitment.

Edina lost hundreds of trees to Dutch elm disease in the 1970s. Dutch elm changed the way trees are planted. “Monoculture is not the best thing to do. If one gets sick, they all do,” says Overholt. Planting a diverse variety of trees is critical for long-term success.

Invasive species are another big tree issue.
“Buckthorn is the new thing,” says Overholt. Removal is ongoing, but off-season temperatures can be helpful to the cause. The buckthorn trees are removed, stumps sprayed with herbicide or completely dug up so they don’t grow back. Buckthorn likes to sprout new shoots from old roots, as almost any Edina gardener can attest.

Arneson Acres is used as a test site for new trees. In select spots, experimental varieties grow in a controlled environment. “Here and there, we add trees,” says city horticulturist Tim Zimmerman. “We nurture them along and monitor their progress”—American chestnut, northern pecan, Merrill magnolia and northern catalpa to name a few. The idea is to see what can withstand the severity of winter and other challenges. After a species proves sustainable, it may be used in other areas of the city. The method is economical, “We go with a small seedling stash without spending too much,” Zimmerman explains.

Planting Trees at Home

Trees look so simple yet can be complicated in their needs. Proper planting involves a myriad of considerations, not to mention ever-unpredictable and extreme Minnesota weather. Prime planting times extend through the more temperate periods of spring and fall.

All too often the size is overlooked, according to Sunnyside Gardens garden center retail manager Melanie Carlson. Plan for a mature tree when selecting the younger plant. Consider the final height and spread of any tree choice and how the full-grown tree will fit the contour of the landscape, home, outdoor rooms and buildings.

Next comes location, location, location: The spot can make or break a tree’s success. The time of day and actual hours of sunlight factor into a tree’s success, according to Carlson. Maples, birches and crabapples are proven winners and reliable customer favorites. Do some checking to determine best-suited genus and  species for a particular site.

For most planting spots, good soil doesn’t come naturally. Carlson advises planters to amend the soil in the tree planting hole. Replace one-third to one-half of the existing soil with organic compost and peat moss. “Incorporate all throughout like a cake batter,” Carlson says. Remember, the size of the hole corresponds to the size of the tree: Two times as wide as the pot and one and a half times as deep.

Don’t forget the fertilizer—a slow-release version can be a good option. Jump-start growth by fertilizing at the time of planting and maintaining a feeding schedule. “Plants are like people,” says Carlson. “They need food, too.”

Ongoing maintenance includes more fertilizing (but not too much), trimming and watering of an average of 1 inch of water per week during summer and fall dry spells. During the spring, watering might be needed if the snow cover was light.

Year-round protection from hungry wildlife is another consideration. “There’s a severe rabbit problem here,” says Carlson. Reinforced fencing and protective tubes and wrapping are two strategies to combat critter carnage of trees.

If all this sounds like too much to take on for a weekend project, relax. Help is only a phone call away. Sunnyside and other local landscaping businesses sell and plant trees. They can do all the dirty work; but plan ahead—spring is prime season for planting. “For a larger tree, people do need more assistance just because of the size they’re digging,” Carlson says. Staff are available to answer questions customers have about tree planting and selection throughout the process. “We’ve got all the tools they need for success. If they need advice, we’re always here for that too,” she adds.

Tree Planting Cheat Sheet
A short list of things to consider when planting:

  • Mature height – From little seedlings big trees doth grow. Consider the size of the site, how other features might conflict, as well as proximity to power lines.
  • Width – Space requirements vary from thin pyramidal shaped to oval to round to the sprawl of irregular growing patterns.
  • Soil – A rich, fertile soil enriched with organic compost and peat moss helps trees thrive. Too much clay or sand can have the opposite effect. When in doubt have it tested by the University of Minnesota soil testing laboratory ($17 per sample;
  • Shade tolerance – Most trees prefer full sun but many will tolerate some shade. Relatively few trees flourish in full shade. Morning, midday and afternoon sun have different effects on trees.
  • Street proximity – The chemicals used to treat roadways during the winter can harm some trees. Streets must be clear of vegetation to a height of 16 feet; eight feet for sidewalks.
  • Flowers – Some trees, including crabapples and sour cherries, are planted for their flowering beauty alone.
  • Fall color – The spectrum of colors includes yellow, brown, orange, red, maroon and steadfast green.
  • Fruit – A harvest of fruit can be a blessing or a curse. Spraying might be required for a bountiful bug-free harvest of crab apples, sour cherries or other orchard favorites. Some fruits stain pavement and cars.
  • Deciduous or coniferous – Most conifers keep their green to green-blue or green-yellow color year-round, while others shed their needles in the fall. Deciduous trees offer more variety in shape and color but drop their leaves come fall.
  • Animals – From ravenous bunnies to deer, Edina has it all. Take extra precautions with tender young trees and shoots.

Mark the Calendar

Celebrate Arbor Day APRIL 28.