How To Help Your Trees Handle Heat Waves & Heat Stress
With increasing global temperatures, trees around the world are being negatively impacted. From suffering to even dying as a result of heat stress, it’s critical that we take measures now to protect our trees during soaring temps. Learn more about how intense heat affects them and what steps you can take today!
FAQS About Heat and Trees
Are you worried about your trees wilting and yellowing during a summer heat wave? Don’t fret, we have compiled the answers to all your questions! Discover what steps you can take to protect and nourish your trees from the effects of extreme temperatures. With this helpful advice, you will be able to keep them healthy throughout scorching hot days with ease.
How Do Trees Get Hot?
During a heatwave, trees tend to be heated beyond the normal temperature of their surroundings due to sunlight reflecting off objects in close proximity, radiating and/or reflecting from surrounding soil (which can reach up to 140°F!), hot air movement such as warm breezes or convection, and heat radiating from nearby surfaces.
What is the temperature that trees in Buffalo and Clarence can tolerate before they become overly heated?
Ideal growing temperatures for many of our trees range from 70°F to 85°F. As the heat intensifies and climbs beyond 94°F, photosynthesis slows down, depleting a tree’s energy supply. Once temperatures reach 115°F in our area, it is too late; without immediate treatment death or long-term damage will occur – think of it as heat stroke in humans! Trees typically mimic air temperature, so when we start feeling the burning effects of high temps, they do too.
What Happens When Trees Overheat?
It largely depends on the tree’s age, health and soil conditions. Heat is especially damaging to older trees, those in poor condition or growing in a confined area of soil such as between sidewalks or parking lots. Nonetheless, any type of tree can be impacted by heat stress if temperatures become too high.
When a tree is under heat stress, it may display various symptoms including wilting leaves and drooping branches, yellowing needles or interior leaves, sparse canopy growth with little to no new foliage, rust-colored spots on the leaves’ surface plus scorching around their edges in addition to dead/fallen off foliage and sap oozing from lesions on its trunk that are often due to reflected solar warmth.
Can trees find relief by cooling themselves?
Absolutely! Trees employ the same concept as humans to cool themselves in hot weather; they use transpiration. This is when water evaporates from small openings on their leaves, stems and flowers. As we need to stay hydrated for our bodies’ sweat-based cooling system, trees must also absorb enough water through their roots for a successful transpiration process.
When trees are subjected to high temperatures, they perspire more and require greater amounts of water in order to remain cool. As the temperature rises, their energy expenditure grows which means they need an ever increasing amount of hydration until eventually they reach a point where it is no longer enough—this is known as “hitting the wall”.
What measures can we take to protect trees from the devastating effects of a heat wave?
There are various strategies to help trees avoid the harmful effects of heat stress. While some can be employed during a peak temperature event, it is advisable to plan for these solutions beforehand in order to ensure proper protection.
To help your trees combat heat stress, water them properly and consistently. This means watering deeply – reaching the roots that are typically 12 inches below ground – at a slow rate so it absorbs into the soil rather than running off; as well as providing moisture to all parts of the root zone for uniform nourishment. When done correctly, you will maintain proper hydration levels in your tree which is essential for their survival during hot spells!
If the temperature continues to soar, you may need more than just sprinklers or an irrigation system for your lawn. It’s time to drench those trees with a hose on low pressure and move it around every few hours in order to water all of their leaves. This way, they can have that much needed long cool refreshment!
Utilizing water for cooling during a heat wave is an effective way to help both trees and people alike. One strategy is to spray light mist of water near anything that needs relief from the extreme temperatures – such as shrubs, bushes or grasses. As it evaporates quickly, this will cool down surfaces the droplets have landed on while simultaneously reducing air temperature in its vicinity.
Invest in a 2- to 4-inch layer of organic mulch for your tree’s benefit! Mulching the soil surface not only helps maintain moisture levels and ensures cooler temperatures, but it also hinders weed growth and can even reduce nearby heat.
Enhance the health of your trees by surrounding them with organic mulch such as wood chips, bark chips, grass clippings or straw. Spread it generously around your tree’s dripline (the edge of its canopy), yet remain mindful to keep it away from the trunk in order to prevent any fungal issues.
As a rule of thumb, it is usually best to keep other plants away from your tree as young specimens in particular may struggle with competing for soil moisture. That said, companion planting does offer certain advantages. For example, strategically placed deciduous shrubs and large-leaved plants can help shade the ground around smaller trees while still allowing enough sunlight into their canopy to facilitate active photosynthesis. To prevent water stress on your tree, be sure to select drought-tolerant species that won’t require much hydration.
Smaller trees can benefit greatly from landscape structures that provide much needed shade. Adding a pergola, arbor, trellis or even a sail-like structure will help reduce the air and soil temperature around vulnerable trees while also creating an attractive accent in your garden. If you’re feeling creative, try growing some vines on trellises or vigorous climbing plants up and over your arbors to add more depth of shade!
If you can, try to refrain from clearing trees that are providing a cooling shade to heat-stressed ones. Abruptly exposing them to the scorching sun and removing the comforting shadows they have grown accustomed to may push them over their limit, leading straight towards an untimely demise.
Although you may not enjoy it, pruning dead, diseased, damaged or rubbing branches inside a tree during a heatwave is always an option. However, if possible and safe to do so – consider postponing the cutting of dead wood or non-dangerous branches until temperatures cool off.
On the flip side, it is prudent to postpone pruning live branches during extreme heat. Every cut from pruning constitutes an injury and taxes a tree’s energy reserves as it attempts to heal itself. Removing leaves diminishes available energy for wound closure, thereby making healing even more difficult, while simultaneously weakening its evaporative cooling capacity through transpiration.
Don’t Use Nitrogen Fertilizers
For optimal growth, trees should be fertilized in both spring and fall. However, in some cases, it may be beneficial to apply a small amount of organic fertilizer or compost tea during the summer months, depending on the specific conditions.
Do not fertilize trees with high nitrogen fertilizers during very hot or dry weather. These fertilizers encourage quick growth of leaves and stems, which is not beneficial for stressed trees as it requires a lot of energy. It’s better to wait until the next spring when the tree has recovered and produced a complete leaf set.
Using too much fertilizer can raise the salt levels in soil, which may hinder the ability for tree roots to take in water easily. In hot weather, it’s best to use lawn fertilizers sparingly (or opt for a slow-release organic soil amendment) and avoid fertilizing garden beds until temperatures drop.
Don’t Disturb the Roots
In Clarence, New York, summer is typically a time for construction projects. If you’re considering a big landscaping or home renovation project, it’s recommended to avoid doing it during a heat wave. This is not only important for the health of the trees, but also for the workers carrying out the projects. Such projects can accidentally harm the trees by breaking branches, injuring trunks, and most significantly, causing damage or severing roots.
If a tree is stressed and doesn’t have enough healthy roots to absorb water, it will deteriorate rapidly. If you can’t reschedule planned work, create a tree protection plan to safeguard your valuable trees and the surrounding root area before starting construction. Instead of replacing expensive, mature landscape trees in the future, it’s better to prevent them from undergoing unnecessary stress.
STILL HAVE QUESTIONS?
If you’re concerned about your trees being affected by heat stress, feel free to contact us today. We’ll examine your trees and suggest ways to help them recover. Trees enhance the beauty of Buffalo and surrounding areas such as Clarence, Clarence Center, East Amherst, Williamsville, Akron and others. Our aim is to ensure that as many trees as possible remain healthy and resilient even during the most extreme heat spells.