Addressing 6 Common Myths in Arboriculture

Trees have been around forever, yet somehow, there are some myths about tree care that refuse to die.

It’s time to set the record straight, and who better to do it than our very own Master Arborist, Mike Leung, who was recently featured in Green for Life Magazine. Go check it out (after you’re done with this one!)

Myth #1 – Tree Roots Always Damage Foundations

The image of massive roots cracking concrete and invading basements is enough to make anyone second-guess their landscaping choices. But the truth? Tree roots don’t seek out foundations; they follow water and oxygen.

Most tree roots grow in the top 12–24 inches of soil, spreading horizontally rather than deeply. They don’t punch through solid concrete but will exploit existing cracks or weak spots if moisture is present.

In areas with clay-heavy soil, roots can indirectly affect foundations by absorbing water, causing soil shrinkage and minor shifts in the ground. However, this is a natural response to changing soil conditions.

If you’re concerned about foundation damage, the key is smart tree selection and placement. Avoid planting water-hungry species like willows or poplars too close to your home. Instead, opt for trees with less aggressive root systems and plant them at a safe distance.

Regular maintenance, proper irrigation, and consulting an arborist before planting or removing a tree can help prevent issues before they start.

Myth #2 – All Mulch Is Good for Trees

Is mulch good for trees? Yes, but only when used correctly! Done right, it’s a tree’s best friend. Done wrong, it’s an invitation for disease and decay.

Mulch, when used correctly, retains moisture, suppresses weeds, and regulates soil temperature. But not all mulch is beneficial for trees.

One of the biggest mistakes is mulch volcanoes, i.e., piling mulch high against the trunk. While it may look neat, this traps moisture against the bark, creating a breeding ground for rot, fungi, and pests. Instead of protecting the tree, it slowly suffocates it, leading to weakened roots and decay.

Not all mulch materials are equal, either. Rubber mulch, landscape fabric, or gravel may prevent weeds, but they also trap heat and block oxygen flow, stressing the tree instead of nourishing it. Even organic mulch can be problematic if it’s applied too thickly, preventing water from reaching the roots.

For best results, use organic mulch like wood chips, shredded bark, or compost. Spread it in a 2–4 inch layer, keeping it at least a few inches away from the trunk. This allows for proper moisture retention and airflow while still protecting the root zone.

Myth #3 – Trees Heal Their Wounds Like Humans

It’s a common belief that trees can heal themselves like us humans. The truth? Trees don’t heal; they seal. Unlike human skin, which regenerates, tree wounds remain permanently exposed.

Instead of repairing damaged tissue, trees compartmentalize the injury through a process called CODIT (Compartmentalization of Decay in Trees), effectively sealing off the damaged area to prevent decay from spreading.

A tree does this by forming specialized internal barriers, which slow or stop the disease from moving deeper into the wood. However, this process isn’t perfect, and improper cuts or large wounds can still leave trees vulnerable to pests, fungi, and decay.

That’s why proper pruning techniques are so important. Cutting just outside the branch collar allows the tree to seal off the wound naturally. Cutting too close or leaving a stub prevents proper sealing, making the tree more susceptible to rot.

Another outdated practice is using wound dressings or sealants to "help" trees recover. Studies have shown that these products do more harm than good, trapping moisture and slowing the sealing process.

Myth #4 – Topping Trees is a Good Way to Reduce Size

If a tree outgrows its space, the quick-fix solution might seem simple: cut the top off to make it smaller. This is known as tree topping, and while it might seem like a good way to control size, it’s actually one of the worst things you can do to a tree.

Topping removes large portions of a tree’s canopy, forcing it into survival mode. In response, the tree produces rapid, weak regrowth, often in the form of thin, unstable branches that grow back even faster than before. These new limbs are poorly attached and prone to breaking, making the tree more hazardous than before it was topped.

Beyond structural issues, topping also exposes large wounds that trees struggle to seal, increasing their vulnerability to disease, decay, and pest infestations. Many topped trees decline rapidly and often require removal within a few years due to poor health.

A better approach is crown reduction pruning, where selective cuts are made to shorten and reshape the tree while maintaining its natural structure. This method allows the tree to stay strong, balanced, and healthy without causing unnecessary stress.

Myth #5 – Trees Need to Be Staked for Support After Planting

You’ve probably seen newly planted trees tightly staked and secured. It’s a common misconception that staking is necessary for all young trees to help them grow straight and strong. But in most cases, staking does more harm than good and can actually weaken a tree’s development.

Trees that grow without stakes develop stronger trunks and root systems because they naturally adapt to wind and environmental conditions. When a tree is staked too tightly or for too long, it fails to build its own structural strength, leaving it dependent on artificial support. Over time, this can lead to a weaker trunk, poor root anchoring, and an increased risk of breakage once the stakes are removed.

Another problem with staking is girdling. If the ties are too tight, they can dig into the bark, cutting off nutrient flow and damaging the tree. In extreme cases, improper staking can cause the tree to snap at the point of attachment during strong winds.

The best thing to do is only stake a tree if absolutely necessary—for instance, if it was planted in a high-wind area or has an unstable root ball. If staking is needed, use loose, flexible ties and remove them after one growing season to encourage independent growth.

Myth #6 – More Fertilizer Means a Healthier Tree

It’s easy to assume that feeding trees more fertilizer will make them grow faster and stronger, but trees don’t work like houseplants. Over-fertilization can actually lead to weak growth, poor root development, and increased vulnerability to pests and disease.

Unlike grass or garden plants, mature trees don’t need frequent fertilization if they’re planted in nutrient-rich soil. Applying too much nitrogen can force rapid, weak growth, making branches more susceptible to breakage. Excess fertilizer can also burn roots, disrupt soil balance, and contribute to environmental pollution as runoff enters waterways.

Instead of piling on the fertilizer, focus on soil health. A layer of organic mulch, compost, or natural amendments provides a slow, steady release of nutrients. We also recommend our RootBoost™, which provides nutrients directly to the roots of your trees and shrubs, keeping them growing strong during every season and providing stronger disease resistance.

Smart Tree Care, No Guesswork With Green Drop

Tree care isn’t about old wives’ tales and outdated advice. You need to look at the science and make decisions that help your trees.

Whether it’s pruning, disease prevention, or urban tree management, our ISA-certified arborists and Master Arborists bring the expertise to keep your trees healthy and strong all year round.

If you’re ready to ditch the myths and give your trees the expert care they deserve, book a consultation with us today. It’s free!