How not to kill a tree

Weeding out garden myths: This article from the Cincinatti Post separates some surprising facts from fiction. Make sure you read it before you plant your next tree.

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Weeding out garden myths

By Joel M. Lerner
Washington Post

“Everybody knows … everybody says …”

These are deceptive words in gardening. Just because something is conventional doesn’t mean it’s wisdom. A lot of views “everybody” subscribes to in gardening are simply myths, and some ideas that have been accepted by “experts” have, with more time and research, proved to be wrong. There are lots of garden myths out there, so while you’re enjoying the cozy indoors, let’s take on a few of them.

•  Myth 1: Newly planted trees need to be staked and guy-wired.

This is generally incorrect. Balled and burlapped and large container trees are bottom-heavy enough to stand on their own. Wiring kills far more trees than it helps because, in most cases, the wires are never removed. The only living part of a tree trunk is the layer of living tissue, called cambium, just under the bark. When the tree grows enough to embed the wire, the pathway of life-giving nutrients is cut off. Eventually the tree will grow past the depth of the living wood and die.

Plant the tree in the ground properly and leave it to bend in the wind. It will grow stronger in the process. If it’s a little crooked, you can easily straighten it the following season.

•  Myth 2: When planting a new tree or woody shrub, dig the hole twice as wide and twice as deep as the root ball.

The latest research concludes that new trees and shrubs need a solid platform on which to rest. Planting trees and shrubs too deep is another big mistake that can kill the plant. What you want to avoid is getting the root collar (the flare just above the point where the roots join the main trunk) covered by soil or mulch. The roots need moisture, but the bark and trunk need air. If you cover the root collar, soil against the bark of the tree will rot it, causing the same girdling effect as wire. The plant won’t die right away, but it might decline over years. If you have a balled and burlapped tree, make sure to remove any ties that are holding the burlap to the trunk or stems. If you leave them, they will girdle the plant and eventually kill it.

When planting the root ball, install it approximately 25 percent higher than ground level. Toward the outside of the area where the root ball will be placed, you can dig a little deeper. Place the tree or shrub and fill the hole with a mixture that’s one-third compost and two-thirds native soil. Pack it firmly so there are no air pockets. Water it well, and make sure the soil stays moist, not wet, while the plant establishes itself, or until the ground freezes, if you’re planting in fall or early winter.

•  Myth 3: Newly planted trees and shrubs should be fed regularly.

Trees don’t eat. They drink. They don’t need more fertilizer, they need water to absorb the nutrients that are already available in the soil. Trees and woody shrubs get their nourishment by absorbing nutrient-rich moisture through their cells — the process of osmosis. They need properly moist soil that is airy enough to allow the roots to grow and absorb the minerals that the soil holds. Clay is loaded with minerals. If it’s mixed with enough organic matter, it will be easy for the roots to reach out and take what they need.

Test soil before planting. The pH, or acid-to-alkaline balance, must be correct. Have soil tested through your state’s Cooperative Extension Service (county offices).

•  Myth 4: Plants must be watered constantly.

Plants need to be watered when they need water — and not before or after. Just stick your finger in the soil. If it’s dry, water. If it’s moist, don’t. If you overwater plants, you will often kill them.

•  Myth 5: Drought-tolerant plants don’t need to be watered.

Yes they do, especially when they are just becoming established. Xeriscaping, the practice of using native plants to minimize watering, doesn’t mean giving up watering. The key to any xeriscape is proper water management. Drip irrigation and spray heads should be used where necessary.

Lerner is president of Environmental Design in Capitol View Park, Md., and author of “Anyone Can Landscape” (Ball 2001).

Publication Date: 01-29-2005

One thought on “How not to kill a tree

  1. The only thing I’d add to that excellent article is that another prime killer of trees and shrubs is the mulch volcano, so popular here in New England. I’m not sure if it’s our cold winters that lead people not only to over-mulch everything in their gardens but to make sure that the mulch comes right up to the trunk/base of the plant just like a turtle-neck sweater, leading to rot or insect infestation or rodent attacks. In part I think they feel that a nice deep layer of pine bark makes things look tidy, plus they like the colour, and the smell of the pine. Of course the garden centres push mulch because they make a wad off it with essentially no work.
    BTW I always enjoy your posts on OGD, which certainly has been flaming more than usual in the last six months or so, hasn’t it…
    It also seems to me that the current strain of invective coincided with the return (or emergence from the woodwork) of Andy Easton.
    Mind you, I’ve no objection to academics jabbing and sniping at each other & their work, as used to be the case a few years ago, for the most part it was amusing, interesting & frequently informative, plus it wasn’t an everyday event.
    Cheers from The Frozen North (MA)
    Nice website!!!!


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