How to Protect Your Trees From Storm Damage

Every monsoon an alarming number of desert trees lose large limbs or are completely uprooted. It can be upsetting to see a beautiful tree meet such a devastating end. Why does this happen? And is there anything you can do to protect your trees from storm damage?

Anecdotally, many Tucson residents are finding the past few years have gotten windier and storms have become more damaging. After recent storms, local news stations reported unprecedented damage. This video shows a jaw-droppingly long line of trucks waiting to drop off fallen trees and branches at a recycling facility.

Even Reid Park Zoo, which normally welcomes branch donations for their animals, had to turn away offerings because they had more than they could handle.

Clearly, there is nothing you can do to stop the wind which, if strong enough, can take down even the most perfectly-suited tree.

But sadly, most storm damage is due to “human error.”

Here’s a look at the five factors responsible for causing most of the storm damage.

The first three are things that any tree owner can take action on today. The last two involve choosing trees wisely before they are planted.

Improper Watering

The first thing you can do to protect your trees from storm damage is to adjust your watering schedule.

90% of desert homeowners water their trees incorrectly. A typical “landscaper default” watering schedule is 20 minutes three times per week, with 1 or 2 emitters placed near the tree trunk.

Here’s what’s wrong with that scenario.

• A tree on that schedule is watered too frequently. (A mature tree only needs water every 2 weeks to 2 months depending on the season, canopy size, and type of tree.)
• A tree on that schedule will not get enough water with each watering. (Trees should be watered to a depth of 3 feet every time.)
• The emitters should be moved to the tree’s drip line and more emitters should be added as the tree grows.

Since tree roots grow towards water, shallow frequent watering ensures that roots never grow deep or wide enough to adequately anchor the tree, making it susceptible to storm damage.

Another way you can go wrong is by watering too much. This forces the tree to grow abnormally fast, resulting in soft wood that easily breaks during a storm. Desert-adapted trees, once established, rarely need any irrigation.

The Solution: Check your irrigation schedule and adjust as needed. Refer to How to Water Desert Trees: How Often? How Much? This article provides everything you need to know, including easy-to-read charts, to properly water your trees.

Bad Pruning

When trees grow too big for their space or have damaged branches, they need to be pruned. But frustratingly, more trees are pruned badly than not. Bad pruning is so rampant here in Tucson there’s actually a Facebook group called “Tucson Hates Trees.” It sure looks and feels that way.

It’s not hard to find examples of badly pruned (i.e., “butchered”) trees. Here are some of the more egregious types of bad pruning:

• Trees are lion-tailed where just the tips of branches are left.
• Trees are topped off where the outer-most branches are cut back like a shrub.
• Trees that should have multiple trunks are trained into a single-trunk tree.
• And then there is the haphazard removal of branches for no particular reason other than the “landscaper” needed to justify getting paid.

The Solution: If you have a tree that needs pruning, hire a certified arborist (not a so-called landscaper). An arborist knows how to properly shape your tree to keep it healthy and reduce its propensity to storm damage.

Tree pruning is not the place to go cheap. Yes, an arborist will initially cost you more than a guy with a chainsaw, but not in the long run. Pay now to have your tree pruned right. You’ll pay a lot more later when it needs to be removed.

Improper Staking (or none where it’s needed)

Mature trees rarely need staking, but young trees may need to be staked for the first few years to give them the best chance of weathering wind and storms.

If you have trees that are staked or that you think may need staking, see Civano Nursery’s step-by-step instructions on how to properly stake a tree. Improper staking will do little to keep a tree upright and often does more harm than good.

Planting the Wrong Tree

Now, let’s look at the first way that trees are doomed from the start. Landscapers, builders, and municipalities plant tree species that are known to be susceptible to storm damage. And garden centers still sell these same trees to unsuspecting homeowners.

Let’s take a look at three common trees known for storm damage.

A Dramatic Case: Desert Museum Palo Verde

A notable case in point is the Desert Museum palo verde (Parkinsonia x ‘Desert Museum’). You’d assume that a native tree named after the renowned Arizona-Sonoran Desert Museum would be an outstanding landscape plant, but that has not been the case.

This hybrid of Mexican, blue, and foothills palo verdes was supposed to have the best traits of all three trees (gorgeous flowers, no thorns, and fast-growing) but in reality has been a disaster. These trees grow fast — too fast — and consequently have weak wood and are very prone to storm damage. If you see a row of palo verdes down after a storm, it’s often this hybrid.

Non-Native Mesquite Trees

Another popular tree that suffers from a disproportionate amount of storm damage is the Chilean mesquite (Prosopis chilensis). They grow fast and have weaker wood and naturally less robust root systems compared to native mesquites. A better choice is the velvet mesquite (Prosopis velutina), a Sonoran Desert native that evolved to withstand our desert storms.

Willow Acacia

Willow acacia (Acacia salicina) is an Australian native commonly planted in the southwest. But unfortunately, it grows fast (ultimately reaching 50 feet tall and 20 feet wide), has weak wood and a shallow root system, and is very prone to storm damage.

If you have one that you want to go the distance, it’s imperative that you water, stake, and prune it correctly.

If you can see that your tree will outgrow its space or otherwise be a hazard, consider removing it pre-emptively before it damages your car, your house, or other structures.

Change Your Notion of What a Tree Should Look Like

Another problem is planting single-trunk “lollipop trees,” the kind most of us are used to seeing in other parts of the country. Nurseries sell these because:

• Customers want them. It’s what they are familiar with and what they tend to buy.
• These trees take up less space and are easier for nurseries to grow and transport.

But these trees are top-heavy and more prone to wind damage.

Look around next time you take a hike. You’ll notice that you never see single-trunk trees growing in the desert. This is not a coincidence!

The Solution: Plant multi-trunked trees and leave them that way. For maximum storm resistance, plant native trees that have evolved to withstand our monsoon storms.

Planting a Tree in the Wrong Place

The second way that trees are set up to suffer from storm damage is by being planted in the wrong place.

Many trees are not planted with their mature size in mind. They are planted in small yards or crowded parking lots. When the tree grows too large for its space, it gets pruned, often hacked, to reduce its size, making it more susceptible to wind damage.

When a tree is surrounded by impermeable surfaces such as concrete, pavers, or asphalt, the roots can’t grow wide and consequently anchoring roots are never formed.

You may have heard that a tree’s root system is as big as the tree canopy, but that’s an understatement. According to the University of Arizona, the root system of a healthy tree should grow to be 1.5 to 4 times beyond the width of the tree canopy! But often trees are planted where this is not remotely possible.

A tree planted in the “hell strip” (that area between the street and the sidewalk) has particular challenges. Since the little piece of ground is the only permeable place it can access water, the root system stays small.

Here’s a picture of a tree that recently blew over in my neighborhood.

This tree had two strikes against it. It was a Desert Museum palo verde and it was planted in the hell strip. The tree was least 20 feet tall, but the root ball is only a few feet wide and deep. This poor tree never stood a chance.

The Solution: Check the mature size of any tree before you plant it. Confirm you’ve got enough space to let the crown and the roots grow as nature intended.

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Photo Credit

Denver Water