3 Little-Known Facts About Tree Care

by James Florence
tree service pruning large tree

From irrigation to pruning, trees require ongoing maintenance to stay healthy. However, there are things most people don’t know about caring for trees that can have a big impact on their health. Read on to learn three little-known facts about tree care.


1. A Tree’s Trunk is a “No Moisture” Zone

Like any plant, trees need water to thrive. That’s why experts recommend watering your trees regularly and putting down mulch to minimize evaporation. However, there’s a catch: You should never water or put mulch too close to a tree’s trunk. In fact, you shouldn’t come anywhere near it.

Putting mulch too close to a tree’s trunk can be especially problematic. Mulch consists of dead tree and plant material that’s actively decaying, and as it decays, it releases nutrients that enrich the soil. Because of this, mulch contains active bacteria and fungi, which, if situated too close to the tree, can spread to the trunk and cause the tree to become diseased. That’s why, when mulching, it’s important to maintain a buffer zone of 12 to 18 inches out from the trunk.

When it comes to irrigation, you want to go even further away from the trunk. Consider the way a tree naturally sheds water. When it rains, water hits the top of the tree and cascades off of the highest limb to subsequent limbs. As it does this, it progresses outward to the edge of the canopy—the furthest extent of the lower branches (known as the “drip line”). Since this is where trees are used to getting water, it makes sense to irrigate in a similar area.

Of course, a tree’s roots extend much farther than the drip line, both inward and outward. To ensure a broad, even distribution of water, use the following method to establish your irrigation zone:

  1. Estimate the distance from the trunk to the drip line and find the halfway point.
  2. Start watering at the halfway point and go outward until you reach the tree’s drip line.
  3. Continue outward from the drip line for roughly the same distance (so as to double your initial span).


tree root crown buffer zone

When putting mulch around a tree, maintain a buffer zone of 12 to 18 inches away from the trunk. Photo: Advance Tree Service, Inc. ©2021

2. Trees Can Get Sunburned

Everyone knows the sun’s UV rays are harmful to humans, but did you know they can damage a tree’s epidermis as well? Here are a couple of scenarios in which a tree may be susceptible to sun damage:

Young trees

Young trees’ thin bark makes them especially vulnerable to damage from excessive sun exposure. In some cases, a tree’s inner heartwood can become exposed, which can be fatal. Since a tree’s heartwood is technically dead, it can’t heal itself, which means you have dead tissue on top of dead tissue. This can leave a permanent gaping wound that leaves the tree wide open to fungal infection and insect infestation.

Sudden exposure

Another scenario is when a previously shaded tree is suddenly exposed to direct sunlight. Let’s say you have a bunch of six-foot shrubs in front of a mature tree and you decide to pull them all out and replace them with succulents. All of a sudden, direct sunlight is hitting this tree that hasn’t seen sunlight in years. This sudden exposure can cause a healthy, mature tree to become unhealthy very quickly.

To protect vulnerable trees on your property, you’ll need to put sun scorch protection in place. A common DIY method is wrapping the trunks with white paper up to the first branch. The paper—which will reflect the sun’s heat off of the tree—should overlap roughly 33% each time around the trunk. You can also purchase a “tree guard” product that’s specifically designed for this purpose.


overgrown lemon tree

Over-pruning a tree can backfire, resulting in overgrowth.

3. Overpruning Can Lead to Overgrowth

Are you tired of pruning your trees? Perhaps you’ve considered pruning them back further to increase the intervals between prunings. Unfortunately, overpruning a tree can have the opposite effect and result in the need to prune sooner.

When a tree’s branches get overpruned, its reaction is to bush back out as quickly as possible. It does this to regain its foliage, which it needs for photosynthesis. This is especially true of young, healthy trees, which will grow back with vigor if overpruned.

What’s worse, when you spark this kind of reaction in a tree, the accelerated rate of growth can result in structurally weak limbs. So, not only will you have to prune your trees again sooner than expected, you may also unwittingly jeopardize their health. For this reason, when it comes to pruning trees, it’s better to follow recommended procedure. And if you’re really tired of DIY pruning, consider hiring a local tree maintenance service to handle it for you.

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