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.
Do you ever wonder where insects go during the winter? This year, as you snuggle up under a warm blanket to escape the winter cold, think about how you can help the beneficial insects in your garden do the same. The harsh conditions of the cold season can be challenging to deal with, but some insects can benefit from habitats that provide them with shelter not only during the winter but all year round. Ground beetles are a great example of insects that can be a tremendous help in the garden, but also appreciate a good nook or cranny to hide out in while the weather is less than ideal.
Ground beetles are one of the most diverse insect families in the world and can be found in many shapes and sizes across Maryland’s gardens, farms, and natural areas. Like butterflies and moths, ground beetles go through a complete metamorphosis, changing drastically in appearance throughout their life cycle. They begin their lives as larvae that resemble small, fast-moving, armor-plated caterpillars with giant mandibles – a little intimidating, but luckily, they’re on your side! Ground beetle larvae mostly feed on other small invertebrates, including a range of garden pests like aphids, grubs, and caterpillars. Ground beetles generally spend a few months as a larva and can live several more years as an adult.
Ground beetle larva with a potential snack. Photo: Benjamin Burgunder (CC-BY)
Adult ground beetles can be anywhere from ⅛ to 1 ½ inches long and oval-shaped with a plain dark coloration, but some may sport a green or bronze iridescence. They have long legs and thread-like antennae. Like other beetles, they have hard wing covers, usually with prominent ridges running across their length. These wing covers protect hind wings that may sometimes be used to fly, but many species have lost this ability. Even those that retain it are more likely to be found running across the ground or burrowing down just underneath the substrate.
Ground beetles have large, powerful mandibles that they use to capture and chew their food, which they’re not picky about. They are well-known for eating a wide variety of foods, but many species have a preference for one type over another. Some species, including Chlaenius aestivus, Scarites subterraneus, and Poecilus chalcites are famous predators of other invertebrates including aphids, caterpillars, and slugs, and can help keep pests at bay in your garden. Other species such as Amara aenea, Harpalus pensylvanicus, and Anisodactylus sanctaecrucis also feed on other invertebrates, but have additionally been studied for their useful tendency to eat the seeds of common weeds, helping to manage these weeds before they even start growing.
Some common ground beetle species in Maryland include insect pest predators Chlaenius aestivus (top left) and Scarites subterraneus (top right), as well as weed seed eaters Amara aenea (bottom left) and Harpalus pensylvanicus (bottom right). Photos: Zachary Dankowicz, Debbie Johnson, Martin Galli, Don Marsille (CC BY-NC)
While ground beetles do not damage garden plants, they may be considered a household pest if found wandering through homes. Most ground beetles are nocturnal and attracted to lights, so they may inadvertently enter houses and have trouble getting out. In this case, simply use a cup and a piece of paper or your hands to capture them. They do not pose any significant danger to you or your pets, but if handled roughly, their mandibles may deliver a small pinch. Relocate them outside where they can continue to serve you and your garden.
If you want to help support these useful critters, there are several actions you can take.
Avoid practices that disturb soil fauna such as frequent tillage, and don’t use broad-spectrum insecticides, i.e. those that harm a wide range of insects including beneficials.
Don’t leave the ground bare. Bare earth does not provide the best protection against the cold, so cutting back your plants before or during the winter to tidy up your garden actually may be harmful to resident ground beetles. Applying a straw mulch can help cover up bare earth and provide shelter for these overwintering insects. Planting perennials in or near your garden can also provide a lasting habitat for beneficial insects. Establishing stretches of perennial grasses called “beetle banks” is a common technique used to increase ground beetle numbers on farms in many places around the world.
Create sheltered spaces. Ground beetles will even hide out underneath large stones, logs, or brush piles. In addition to helping ground beetles, creating sheltered habitats and leaving ground cover over the soil can also help other beneficial insects, including pollinators and insects that are important food for birds (“leave the leaves!”).
Because they can live for several years, helping ground beetles for one year can result in much greater numbers during the following years as well. It’s an investment in your garden’s natural defenses against pests! Having these predators around can help keep you from needing to resort to using pesticides which may be harmful to your health and to the environment. Next time you’re making plans for your garden, consider helping out your garden’s natural protectors and enjoy as they return the favor.
References
Dennis, P., Thomas, M. B., & Sotherton, N. W. (1994). Structural Features of Field Boundaries Which Influence the Overwintering Densities of Beneficial Arthropod Predators. The Journal of Applied Ecology, 31(2), 361. https://doi.org/10.2307/2404550
Jordan, S. F., Hopwood, J., & Morris, S. (2020). Nesting & Overwintering Habitat for Pollinators & Other Beneficial Insects. The Xerces Society for Invertebrate Conservation.
MacLeod, A., Wratten, S. D., Sotherton, N. W., & Thomas, M. B. (2004). “Beetle banks” as refuges for beneficial arthropods in farmland: Long-term changes in predator communities and habitat. Agricultural and Forest Entomology, 6(2), 147–154. https://doi.org/10.1111/j.1461-9563.2004.00215.x
Philpott, S. M., Albuquerque, S., Bichier, P., Cohen, H., Egerer, M. H., Kirk, C., & Will, K. W. (2019). Local and Landscape Drivers of Carabid Activity, Species Richness, and Traits in Urban Gardens in Coastal California. Insects, 10(4), Article 4. https://doi.org/10.3390/insects10040112
Philpott, S. M., & Bichier, P. (2017). Local and landscape drivers of predation services in urban gardens. Ecological Applications, 27(3), 966–976. https://doi.org/10.1002/eap.1500
By Alireza Shokoohi, M.S. Student, Department of Entomology, University of Maryland, College Park.
