Plenty of Ways to Kill a Tree
Disclaimer: This article revises Bonnie Appleton’s more entertaining Virginia Cooperative Extension publication 430-210 titled “24 Ways to Kill a Tree.” It builds on the work of Carolyn Rhondeau.
Trees have a way of dominating the first impression of visitors to our homes. Older trees imply historic significance to a place because they typically outlive their owners. Larger specimens frame the view from the street and provide priceless shade. Color, texture, leaves, flowers, seed and fruit mark the changing seasons for the neighborhood. Even a sapling will tell a story about plans and hopes for the future. Despite these unspoken yet noble sentiments, the sad truth is that damaged trees and poorly-tended trees cause passers-by to shake their heads in wonder at our negligence.
Although they may appear to be, and often are, the toughest plants we will own, if we take them for granted we do ourselves no favors. Here are some of the ways we treat trees: the good, the bad and the ugly.
Ugly and Bad planting habits:
- Planting close to a building or other structure reduces growing space above and below ground.
- Leaving a tree staked too long can allow guy wires or rope to girdle the trunk.
- Leaving paper wrap in place constricts the trunk and causes rot in the bark.
- Leaving the nursery wire or rope wrapped around a balled-and-burlapped tree will girdle the trunk.
- Planting near a downspout gives too much water and encourages shallow roots.
- Leaving the top of the wire basket intact from the nursery also girdles the trunk.
- Leaving treated or synthetic burlap in place prevents root growth.
- Digging the hole too narrow discourages proper root spread and will result in a tree that is vulnerable to high winds.
- Digging the hole too deep or letting gravel stay in the hole, which can drown the roots.
Good Planting begins with knowing the height and spread of the mature tree’s branches so it will have room to grow away from obstacles. By the same token, space it away from a downspout and too much water. Especially for trees, dig the hole twice as deep and twice as wide as the spread of the roots. Do not amend the back-fill. Your goal is to site the trunk at the same depth it grew in the nursery.
If the plant is not bare root (many trees from local stores will be balled and burlapped), remove at least the top half of the wire or rope holding the balled root and all of any treated or synthetic burlap enclosing the root-ball. Most of the specimens a homeowner buys to put in the ground will not need to be staked. If you must use stakes, removing them after the first year will allow the roots to grow into their job of support. When the nursery has wrapped the trunk with paper, this needs to be removed. To protect your tree from nibbling deer, surround it with a wire cage wide enough to keep the nibblers out. Switches (very young trees) may need a tubular deer guard which can be replaced with the cage after a couple of years.
Ugly, useless and/or destructive pruning:
- Pruning in summer.
- “Topping” the tallest branches to maintain the height you want; but see the following mistake.
- Allowing a “V” shaped fork with two co-dominant leaders.
- Leaving branches that cross and rub each other.
- Coating pruning cuts with any sealer.
- Failing to remove broken or dead branches.
- Leaving stubs of branches after pruning or creating the opposite problem of making flush cuts (“flush cuts” are flush with the trunk, cuts made inside the swollen branch collar).
Good Pruning is a skill that starts by learning to recognize the collar of a branch near the point of attachment. The collar will show a slight swelling of the bark at the base of the limb. Make the cut to leave the collar in place so it will grow quickly to cover the cut. Stubs of cut branches invite problems just as flush cuts do because the tree cannot heal itself.
Reducing the height of a tree may require a professional. “Topping” often induces vertical water sprouts which have to be removed later. When a tree is young, select a single upright leader and remove others that compete. Crossing branches need to be pruned because rubbing opens a wound for insects and disease as does the failure to remove dead wood. Sealing a wound actually keeps it open since the tree cannot naturally grow over the cut.
Here’s a general rule that with rare exceptions guides my pruning: prune in winter or before spring to insure that not too much sap will leak from the open cut.
Evil maintenance practices:
- Scraping the roots and trunk with lawn equipment, including a string trimmer, which cuts off nutrients and water; remember, bark is alive.
- Ripping through the roots in order to dig a trench.
- Attaching items to the tree that damage the bark and girdle the branch or the trunk.
- Mulching closer than six inches to the trunk.
- Using non-porous black plastic above the roots.
- Stacking heavy items around the tree.
- Allowing weed-killing herbicides to drift on to the leaves of nearby trees.
Good maintenance keeps in mind that despite its heft, a tree is not impervious to harm. Any time lawn equipment contacts the bark, damage can happen. Mulch reduces the likelihood of chance encounters. but we never want to pile mulch against the base of a tree because this encourages shallow, adventitious roots. Two to four inches of mulch is enough to keep soil moist while permitting rain water to penetrate. If you must dig through a major root, prune it as you would a branch. Although trees are handy for hanging swings and birdhouses, these additions can wear through and girdle the bark. Likewise the soil around roots can became compacted by heavy traffic or weighty objects.
Trees are sturdy supports for hammocks and all sorts of lawn accoutrements. Most of the time, inserting a nail or screw into the trunk or large branch is OK because the tree can seal around the insertion. Periodically moving the line that holds a bird-feeder or swing, just an inch or two annually, will avoid strangling the branch.
A good tree takes a long time to reach its prime. It’s worth taking care of it.
“24 Ways to Kill a Tree,” Va.Coop.Ext. Pub.No. 430-210, www.pubs.ext.vt.edu/430-210_pdf