How Do Droughts Affect Your Trees?
It's no secret that trees need water to thrive. Most species can survive periodic droughts, but that does not mean that a lack of water is not stressful for trees. Here's a look at how droughts affect your trees, along with some tips to making these times of low rainfall less stressful.
How do trees react to droughts?
When a tree stops getting a steady supply of water, it responds in a few different ways. First, less water is sent to the leaves, thus reducing the amount of moisture that the tree losses from evaporation through its leaves. Second, the root system is extended. The tree funnels resources into growing longer, more robust roots so that it can extract water from more of the soil around it.
What are the negative consequences of droughts?
Periods of drought can slow a tree's growth dramatically. When water is shuttled away from the leaves, that means less "food" is being made in the leaves, so the tree does not have as many new resources to put into growth. Over time, the tree may become root-heavy, meaning that it has an overly large root system, but not enough leaves to capture enough sunlight to make enough food to support those roots.
Droughts also leave a tree prone to infections, particularly fungal infections like canker diseases and leaf spot diseases. When the tree is focused on conserving resources and surviving a drought, it may not react quickly enough when invaded by pathogenic fungi, and an infection is likely to result.You will then have to have the tree removed to prevent the infection from spreading to other trees.
How can you protect the tree from drought?
You can protect your existing trees from drought by watering them whenever there is a period of low rainfall. To water your tree, simply set a hose about four feet from its base, and let the hose flood the surrounding soil for about an hour. You can move the hose to another location, also about 4 feet from the tree's trunk, halfway through watering if the water is not spreading out well.
You can also apply mulch around the base of the tree. This helps trap moisture in the soil during times of low rainfall.
When selecting new trees for your yard, try to opt for trees that are native to your climate. They will be better equipped to deal with the level of drought stress that is typical for your area, and you won't find yourself needing to water them as often.