Eucalyptus trees can be very annoying for people who live in their own homes because they often fall over. Even though it looks thin and papery, the eucalyptus tree can really hurt buildings or people that it hits. If you live in an area that gets a lot of wind or water, or if the trees are very old, you should keep an eye on them and the weather to help stop any disasters before they happen.
Tree roots not only bring water and food to the tree, but they also hold the tree in place in the ground. Roots can extend down as taproots or spread out around the tree. When something presses against the trunk and branches of an eucalyptus tree, its shallow, spreading roots don’t do a good job of keeping it steady. This can cause the tree to fall.
Eucalyptus trees can be a particular hazard in windy conditions. Winds that are strong enough can easily knock down trees, hitting homes, cars, and people who are in the way. People in Southern California often hear about trees that have been knocked down after big storms or when Santa Ana winds are blowing. For example, the “San Diego Reader” reported that Santa Anas on Feb. 2, 2011, three eucalyptus trees in San Diego’s Balboa Park were knocked over by strong winds. KPBS in San Diego reported that another tree fell onto a freeway connector ramp. Santa Anas are strong, dry, warm winds that come from the desert and blow into Southern California. They make it windy and increase the risk of fires.
With their towering height and peeling bark eucalyptus trees have an iconic presence in California landscapes. But these non-native Australian imports also have a reputation for toppling over easily especially during major storms. So what is it about eucalyptus that makes the trees prone to falling, and is their storm vulnerability deserved?
Eucalyptus species like the blue gum were introduced to California in the mid-1800s and widely planted across the state. Today, questions persist over whether eucs are suitable or safe additions to urban plantings. Their tendency to fail in high winds and rain is central to the debate.
Why Do Eucalyptus Trees Fall in Storms?
There are a few inherent characteristics of eucalyptus trees that contribute to their likelihood of falling over in wet, windy weather:
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Fast growth – Eucalyptus trees grow very quickly, adding long spans of vertical trunk each year. This fast growth results in weaker wood that is more prone to breaking.
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Brittle wood – The wood fibers in eucalyptus are brittle and shred easier than other trees under high winds or a heavy branch burden
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Shallow roots – These trees tend to have sparse, shallow root systems given their height. This provides poor anchoring when strong storm winds blow.
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Top-heaviness – Eucalyptus branches only grow at the top of the trunk, creating dense crowns that act as a sail in windstorms.
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Lack of taper – Younger eucalyptus lack a strong taper from trunk to top, putting more stress on the lower portion of stem.
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Wet ground – Saturated soils easily undermine the stability of shallow eucalyptus roots.
While other tall trees can topple under intense storms as well, these inherent physical traits make eucalyptus uniquely vulnerable to falling compared to native tree species.
Should Eucalyptus Trees be Planted?
The question of whether to plant eucalyptus ultimately comes down to location and risk assessment. Careful siting can mitigate their potential to damage property or harm the public when they fail.
Here are some important factors to consider if planting eucalyptus:
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Avoid planting close to homes, power lines, roads, sidewalks, or other structures. Allow ample distance between the trees and anything they could damage in falling.
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Do not rely on eucalyptus as street trees in urban areas or other high traffic zones. Opt for sturdier, slower-growing options.
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Select smaller maturing eucalyptus species and cultivars where available. Many get quite massive.
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Maintain eucalyptus through regular pruning for structure and lower height.
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Remove lower branches as the trees grow to reduce wind resistance.
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Monitor eucalyptus closely after major storms for signs of instability, and remove any that appear compromised.
While eucalyptus add aesthetic value in the right setting, take care to match the species with the site to prevent future safety issues. Their signature lean and lofty canopies come at the cost of structural integrity compared to many other landscape trees.
Caring for Eucalyptus to Increase Stability
Proper maintenance is key to ensuring your eucalyptus trees stand up to storms. Here are some tips:
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Have a certified arborist conduct a risk assessment to identify potential hazards
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Selectively thin branches and foliage to reduce wind resistance while maintaining form
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Prune judiciously in summer to avoid promoting excessive new growth
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Mulch around the root zone but avoid piling mulch against the trunk
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Stake young trees to build taper and strengthen stems as they establish
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Clean up fallen branches and debris, which attract pests and disease
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Maintain vigor through appropriate watering, fertilization, and pest management
While eucalyptus will always be more vulnerable than other landscape trees, mitigating their inherent risks through location selection and attentive care can allow you to safely enjoy their distinctive charm.
Frequency of Entities:
- eucalyptus: 28 times
- tree: 16 times
- fall: 8 times
- storm: 7 times
- root: 5 times
- wood: 4 times
- branch: 4 times
- wind: 3 times
- plant: 3 times
- prune: 3 times
- grow: 2 times
- shallow: 2 times
- tall: 2 times