Happy Tree Day!

[Paul J Hetzler]

Plant a Legacy on Arbor Day

Muskrat Week. Velcro Month. Arbor Day. You know it’s an obscure event when the greeting-card trade hasn’t bothered to capitalize on it. While not the best-known observance, Arbor Day has a respectable history, as well as a local connection.

Rooted in northern NY, Arbor Day is observed on the last Friday in April. J. Sterling Morton of Adams, NY germinated the concept in 1872 to highlight the need to conserve topsoil and increase timber in his adopted state of Nebraska. Morton was beyond passionate about planting trees, saying “The cultivation of trees is the cultivation of the good, the beautiful and the ennobling in mankind.” I tend to agree. Planting a tree is an investment in the future; an act of generosity toward future generations.

Trees add value to our lives in surprising ways. Many of us are aware trees decrease home energy costs, increase property values, filter pollutants, store carbon and all that goody-gum-tree stuff. But few know that shoppers spend more money when there are trees in a downtown shopping district, and that homes sell faster on tree-lined streets. How about that, green leaves bring out greenbacks.

Hospital patients who can view trees from their beds have better outcomes. Crime rates drop when urban neighborhoods are planted with trees. Plus, lying under a shade tree in summer cures acne. OK, I made that up, but the rest is true.

It may be noble to plant a tree, but it must be done right or you might as well rent it. A poorly planted tree will live a fraction of its potential lifespan. Location is the first thing to consider. If your site is under wires or has restricted space for branches or roots you need the right species and variety that can grow full-size without causing conflicts. Be sure the tree is hardy to your USDA Plant hardiness Zone.

The old adage “dig a $50 hole for a $5 tree” may need to be adjusted for inflation but the idea still has currency. The top ten inches of soil hold 90% of tree roots. Accordingly, a planting hole should be 2-3 times the diameter of the root system, but no deeper. Otherwise the Planting Police will ticket you. OK that’s fiction too, but if an arborist happens by, they may scowl ominously.

It’s imperative the trunk flare be at ground level, because deep planting leads to serious future health problems. For the tree, mainly. Here’s an arborist joke: What do you call a 3-foot-deep planting hole for a tree? Its grave.

Before backfilling, remove all burlap and twine. Wire cages on B&B trees should be cut away or stomped to the bottom of the hole. Container-grown root systems may have circling roots that should be teased out straight—this may require vertical cuts into the root ball.

Adding loads of organic matter to the backfill likely dates back to ancient times, when folks might grab an arborist, if one was handy, and throw them in the planting hole. Possibly in response to this, arborists now recommend little or no additional organic matter in many cases.

With very sandy or heavy clay soils, compost or other amendments can be used in the backfill up to 30% by volume. More can cause a “teacup effect,” and roots may suffocate. Fertilizer is stressful on new transplants, so wait at least a year on that, and then only if a soil test indicates a need for it.

Water thoroughly as you backfill, prodding the soil with a stick to eliminate large air pockets. Unless the site is very windy it’s best not to stake the tree. Movement is critical for strong trunk development. Two to four inches of mulch over the planting area (not touching the trunk) will help conserve moisture and suppress weeds. It’s difficult to over-water a new transplant, but it does happen. Throughout the first season, check the soil every few days to be sure it’s moist but not waterlogged.

Given our long winters, it is good to consider trees with aesthetic interest outside the growing season. Here are some cold-hardy suggestions:

• Hawthorns are salt-tolerant native trees maturing at around 25', good for under utility wires. 'Winter King' has copious persistent fruit that look great in winter & provide bird food.
• River birch are medium-large trees with attractive and unusual pinkish-white exfoliating bark. 'Heritage' is resistant to many pests and diseases.
• Kentucky coffeetrees are tall & drought-tolerant, with few pests & diseases. Their coarse-textured branches produce a striking winter effect—they deserve to be more widely planted.
• For spacious sites, our native bur oak has twisting branches with corky wings; interesting in all seasons. A bur oak silhouette in winter is breathtaking. Especially if it’s real cold. These massive trees tolerate both drought & intermittent flooding, & can live hundreds of years.

Happy Arbor Day on April 26^th—planting a tree is a wonderful activity to share with loved ones, and a great investment in the future.

Paul Hetzler has been a Certified Arborist with the International Society of Arboriculture since 1996, and is a member of ISA-Ontario, NYS Arborists, the Canadian Society of Environmental Biologists, the Canadian Institute of Forestry, and the Society of American Foresters.