As College Station arborists, we are frequently asked about tree care during the warm months of summer. The most commonly asked question is, “Should I be watering my trees?” While each tree and climate will require different watering needs, we have some general guidelines that are good to follow in order to keep your trees happy and healthy during the heat of summer.
How can you tell if your trees need to be watered? There is a simple method you can use to check the soil around each tree to see if they need to be watered. Get a screwdriver that is at least six inches long and probe it into the ground in several spots under the furthest edge of the tree’s canopy, also known as the drip line. If you have trouble probing the screwdriver to a six to eight inch depth and the forecast does not call for rain, it is time to start watering your trees. After you water each tree, use this method again to see if you can probe to the correct depth.
How can you tell if your water hose is putting out the correct amount of water? Most garden hoses will disperse five to ten gallons of water per minute. Knowing how much water your hose is putting out is important because you will use that number to help calculate how long to water each tree. A rule of thumb for watering trees is to give each tree ten gallons of water per inch of trunk diameter. You can test the flow rate of your water hose easily. Grab a five gallon bucket and time how long it takes for your hose to fill the bucket all the way up. After you have done the bucket test, you will be able to more accurately time how long you need to water each of your trees.
How often should you water young trees vs. older trees? A young tree is any tree that has been planted within the last two years and has a trunk diameter of less than one inch. Young trees need to be watered much more often than older trees do. A good guideline to stick to for watering young trees is to water them two to three times each week during warm months. Water each young tree for about a minute using a garden hose with the water flow set to a moderate level. A time saving tip for owners of young trees is to use slow-release tree watering bags around the base of each young tree. Older trees do not need to be watered nearly as often as young trees. Aiming for once a week or every other week watering of older trees is a good rule to follow. This may vary depending on how well the soil around the tree is retaining moisture.
During very dry months, when it has not rained for one month or longer, both older and younger trees will need to be given a deep soaking one to two times a month in order to stay healthy. The most efficient way to give your trees a deep soaking is to water them slowly for an extended period of time. This gives the tree’s roots time to absorb the water as it soaks down into the soil. The roots that absorb the water are not very deep under the soil. Most of them are just 12 inches or so under the surface. Using a soaker hose that applies water to the soil over several hours or using a sprinkler intermittently are two easy ways to give your trees a deep soak. Adding a layer of 3-4 inches of mulch around the trunk of the tree can help retain moisture as well.
What time of day should you water your trees? This is another frequently asked question and for good reason. Watering your trees in the morning or the evening is ideal. Watering during those times of day allows your trees to soak up more of the water than if you were to water them during the heat of the day when the water will evaporate more quickly. As you just learned, your trees need an extended period of time to absorb water. Giving them as much time as possible to do so without having to compete with the sun and the heat is definitely best practice for tree care.
If you would like a consultation with a tree care professional, give Top Point Tree a call today!