Pruning produces plummy results

"It's something I would never have thought of," said my friend, talking about some pruning her son did in their yard, "but I like it."

My friend's son used a thinning cut called skirting, limbing up, or crown raising. My friend is right that most people don't consider this particular cut.

So what exactly is skirting? Cass Turnbull, in "Guide to Pruning," discusses this simple and effective pruning cut. It is simply to remove the lowest branches of a tree so that it looks less bulky and heavy. The cut should be about 1/4 inch above where the original bud began. Be careful that you don't cut into the trunk and that you don't leave a nub.

Turnbull quotes Dr. Alex Shigo, the renowned research scientist known as the Isaac Newton of arboriculture, who says, "Trunk wood is much different from branch wood." The trunk houses the tree's vascular system. Both water and sugar, by means of pipe-like tissues, move up and down through the trunk by zylem, in the center of the tree, and phloem, right under the bark of the tree.

Understanding how close the phloem are to the bark helps us realize why a cut too far into the trunk can damage a tree permanently because it compromises the tree's vascular system. Likewise, cutting into a trunk with a weed whacker or a lawn mower can kill a tree over time.

Skirting, then, removes lower limbs. Remember that trees should look like trees, so don't limb-up more than one-third the tree's visible height.

I recently skirted our azara tree because it was looking bulky and because it was cutting too much light from the Easter lilies growing beneath it.

In an hour's time, the tree looked totally different. The shape of the trunk was visible and its structure was both delicate and textured. The tree looked more handsome, just as a man does when his beard and mustache are well-trimmed.

I used a Felco folding handsaw I purchased at a local nursery, which was much more useful than pruners because of the thick branch diameters.

I'm soon going to tackle a few Japanese maples whose branches are dragging on the ground. Look around your garden and see which trees could use limbing up.

While you have the handsaw in hand, look to see if the tree might use some thinning in its branches, which will allow more sunlight and air circulation into the middle of the tree.

Be careful not to overthin. Just remove those branches that cross one another, rub up next to another branch, jut out in the wrong direction or are dead.

By simply removing these branches, you probably will have pruned properly. Overthinning places too much weight at the ends of other branches. The tree should look full and healthy rather than anorexic.

Some trees, such as ornamental cherries, plums and crab apples, have branches that seem messy. They resent too much pruning and show that by producing lots of water sprouts.

Turnbull says, "If the water sprouts are repeatedly removed every year thereafter, the tree's branches will rapidly age, crack and eventually die."

One good reason to thin a tree is to open a view. Many of us are privy to spectacular panoramas except that there is a tree to block our view.

The most short-sighted treatment is to top it. What will result is that a dense mass of branches and shoots will replace each cut trunk, ultimately creating a denser top than before. Such a top will catch the wind and will increase the risk of the tree falling in a storm.

Also, many topped trees develop root rot, weak branch attachments and rotten or hollow trunks. Sometimes it takes years for this to happen, so we mistakenly think we've made a good decision when we are actually damaging the tree.

Property owners have been sued because topped trees have resulted in falling limbs that have injured property or people.

A much kinder solution to open a view is called windowing. Simply thin the branches that will open the view. Artistically, that implies that you should balance the tree on the other side by windowing another section further down or up higher.

Beverly Hoffman can be reached at

Make the kindest cuts

1) When buying a plant, check the size it will become and add a bit more height because plants grow so well in the Pacific Northwest.

2) If you take out the dead wood and dead leaves, you've accomplished about 80 percent of pruning needed.

3) Prune from the bottom up, not from the top down. Remove branches falling and rubbing against one another.

4) Cutting into the tree trunk, damaging the phloem, can be far worse than pruning a tree in the wrong season.

We encourage an open exchange of ideas on this story's topic, but we ask you to follow our guidelines for respecting community standards. Personal attacks, inappropriate language, and off-topic comments may be removed, and comment privileges revoked, per our Terms of Use. Please see our FAQ if you have questions or concerns about using Facebook to comment.
blog comments powered by Disqus

Read the Oct 26
Green Edition

Browse the print edition page by page, including stories and ads.

Browse the archives.

Friends to Follow

View All Updates