Topping Harms the Health of Trees

A topped tree growing water sprouts. Photo: UME-HGIC

I love trees. I’m betting you do, too. They’re striking and statuesque. They shade us and inspire us, offer wildlife habitat, and provide a backbone to our landscapes.  

But sometimes bad things happen to good trees. Well-intentioned but harmful practices such as topping threaten their health.

Pruning is good for trees. Done well, it can help to control size, remove potentially hazardous branches and improve both appearance and health. But bad pruning is harmful and can kill trees.

Topping – whacking off large limbs indiscriminately to stubs – is a very bad practice indeed. It’s damaging, dangerous, and expensive.

According to Dr. Alex Shigo, the world-renowned scientist and author of books on tree care, topping is the most serious injury you can inflict on a tree.  

Why do people top trees? Most have trees too big for their space and feel topping is a good way to control size and prevent hazards. It’s not. Topping weakens trees.

In fact, a topped tree is much more prone to problems, including poor health and an inclination to drop branches or fall.    

Leaves are food factories for trees. Since topping removes much of the leaf-bearing crown of a tree, it literally starves it.  

Topped trees react by forcing out fistfuls of thin shoots around the cut to make more leaves.  Creating these shoots drains even more energy.

A stressed tree is more vulnerable to insect and disease problems. The large, open wounds topping creates invite attack.  

Good pruning cuts are made where a branch meets the trunk or another branch. Trees can heal this type of cut. Topping cuts in the middle of a branch create ugly stubs that often don’t heal.  

Multiple large cuts – a staple of topping – create serious wounds. The exposed wood often decays and creates a pathway for infection. Columns of decay from repeat topping make a tree more likely to fall.

The multiple thin shoots that form near a topping cut are weak and bring problems all their own. They aren’t anchored in deep tissue like a normal branch, so they tend to break.  

The thick regrowth of new branches also makes a tree top-heavy and more likely to catch the wind in a storm. 

Also, topping is expensive. Topped trees need to be pruned regularly due to the rapid regrowth of all those skinny branches. Repeat toppings are more costly in the long run than proper professional pruning.  

Topping has hidden costs, too. Weakened trees are more likely to cause damage by falling or dropping branches. And disfigured trees do nothing to enhance property values. 

According to the International Society of Arboriculture, well-maintained, healthy trees can add 10 to 20 percent to the value of your property, while topped trees reduce value.  

If a tree has overgrown its space, know that there are better options, including crown reduction or removal and replacement with a smaller tree. Just be safe and leave the big jobs for the pros.    

Here’s our fact sheet on tree pruning that tells you more.   

Topped trees are ugly, unhealthy, hazardous, and costly. Please don’t top your trees. I want you to enjoy happy, healthy trees for a very long time. 

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.

This article was previously published by Herald-Mail Media. Read more by Annette.

Q&A: When Should I Prune Shrub Roses?

Shrub rose pruned back in early March. Photo: M. Talabac

Q:  When do I prune shrub roses? Is now okay? How far back do I cut?

A:  Although you probably won’t kill a plant by doing it now (November) it’s best to wait until late winter or early spring (late February to early March time frame for central Maryland). Pruning before the dormant season might reduce some winter hardiness, potentially contributing to stem dieback. If you pruned in fall and a drastic cold snap were to cause plant tissue damage during the winter, then the second trimming to remove the dead wood would shorten the stem even more, as opposed to delaying trimming until the worst of winter is past and only making one trim at the height you prefer.

The height to reduce the stems depends on personal preference, and recommendations vary, but one convention is to cut shrub rose stems down to about 15 or 18 inches off the ground, though you could go lower to 12 inches or higher to 24 inches. Roses bloom on new growth (except for many climbing roses that also flower on old growth), so pruning at the end of winter will not remove flower buds. If you delay pruning into April or so, though, you might postpone when those first flowers of the season appear.

If a rose is so rangy that it’s just in the way, like arching over a sidewalk or blocking a hose spigot, you can compromise and make a light trim now to tidy it up so the thorns don’t catch people and then do the main pruning in several months.

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. Read more by Miri.

Have a plant or insect question? The University of Maryland Extension has answers! Send your questions and photos to Ask ExtensionOur horticulturists are available to answer your questions online, year-round.

Our Favorite Trees

What are your favorite trees? The Watershed Restoration Specialists from the University of Maryland Extension Sea Grant Program recently shared what their favorite trees are and why.

As Watershed Specialists, we spend a lot of time helping people decide which species of trees might be best for a particular project based on a variety of factors including
sun, soils, and size. Every now and then, people will also see if they can add their favorite tree to the project. Now the number of reasons why people like a particular tree is
probably rivaled by the number of grains of sand on the beach and there’s not enough room in this article to list them all. But this got me to thinking; we spend so much
time talking to other people about trees, I wonder what our favorite ones are? Well, below is the answer to that very question. And after reading this, drop any one of us an email and let us know what your favorite tree is and why.

paw paw tree flowers and fruits
Paw Paw

Amanda – Paw Paw (Asimina triloba)
As an eastern North American native species, not only does Paw Paw have a very distinctive flower, it produces one of the largest edible fruits of all our native trees. The main reason this is Amanda’s choice of favorite native tree is that her son loves the fruit! And because of recent interest in Paw Paw fruit, it has earned the nickname Hipster Banana.

Jackie – Red Maple (Acer rubrum)
Red Maples live up to their name: they give us that first shimmer of red in early spring with its flowers and seeds and wraps up the year with fiery red leaves in the fall. Even
though its nickname is Swamp Maple, Jackie appreciates Red Maples not only for their color, she’s actually made syrup from its sap!

red maple tree and flowers
Red Maple

Kelsey – Willow Oak (Quercus phellos)
A tree she grew up with in her home state of Michigan, Kelsey’s favorite is the Willow Oak. This fast-growing species produces plenty of acorns which keeps the squirrels busy, it also casts a great shadow on her apartment, something she appreciates during the summer months.

willow oak trees and acorn
Willow Oak

Jennifer – Tulip Poplar (Liriodendron tulipifera)
Earning its name from a coffee-cup sized flower that people don’t often see since they’re so high up in the tree, the Tulip Poplar is Jen’s favorite. This tall growing tree is important to a number of birds and butterflies. And its cat-shaped leaf reminds her of the two felines that are really in charge of her house.

tulip poplar tree flower and leaf
Tulip Poplar

Eric – Black Gum (Nyssa sylvatica)
My fave is the Black Gum. I grew to appreciate it over time because of the wide variety of conditions it grows in. And when people tell me they love the red color of a Burning Bush, which can invade natural areas, I often suggest that plants like Black Gum not only have a beautiful red color, they produce flowers and fruit that are beneficial to native insects and animals.

black gum tree red foliage
Black Gum

By Eric Buehl, Senior Agent Associate, Sea Grant Extension Programs. This article was published originally in the Maryland Sea Grant Headwaters Newsletter, October 2019.