Taking care of any plant life in Minnesota is hard. After a long winter, we have a few months of sun before plunging into negative temperatures again. The average summer temperature in Minnesota hovers around 50 to 80 degrees Fahrenheit. For the average homeowner, it’s hard to know how and when to water.
Not only do you have to consider the climate, but the best way to water will also depend on the type of tree, its location, and its age. For homeowners who don’t know where to start, here’s our guide to watering your Minnesota trees in summertime.
Trees transport most of the water they receive up to the top of the tree. This solar-powered process is called transpiration. During transpiration, the roots absorb the water from the soil into the stems and leaves. The water moves from the leaves into the atmosphere through the stomata. Plants lose at least 90% of their water in transpiration. They use the remaining water for plant growth and development.
Water is vital to plant growth and development. It comprises 80-90% of growing tissues in the leaves and roots. It also fuels photosynthesis, defends against pests, and transports nutrients.
During drought, trees won’t get as much water from the ground. If trees don’t get enough water, they aren’t able to grow. Leaves will be yellow or brown, and root development will decrease. When trees reach this stage, they start to shut down and become targets for diseases and insects.
Newly planted trees need regular watering for approximately two years until the root systems are established. Young trees need more frequent watering than established trees. For the first two years, they need regular watering.
After planting, water the new tree daily for two weeks. Then, water every two to three days until the tree has been planted for 12 weeks. After 12 weeks, water weekly until the roots are established. During dry periods in the summer, new trees should be watered one to two times a week. You can skip watering if it rains more than an inch weekly.
Using the right amount of water is essential to tree health, especially for new trees. Under-watering can affect tree growth, and over-watering can cause root suffocation. Both can kill a tree.
New trees need about a gallon and a half of water daily for the first two weeks in the ground. As the roots grow and spread, the tree will need more water. To figure out how much water a tree needs, measure the tree trunk’s diameter. This measurement is the trunk caliper. As a general rule, newly planted trees need one to one and a half gallons of water per inch of trunk caliper.
Trees are established when the root spread equals the spread of the tree canopy. In Minnesota, this generally takes around two years. The larger the caliper of the tree trunk, the longer it will take the root systems to establish.
Mature trees don’t need frequent watering unless there is a drought. During long periods without rainfall, trees may die without supplemental irrigation. As the climate warms, there may be a need for homeowners to water their mature trees.
During periods of consistent rainfall, an established tree won’t need much supplemental watering. But, during long periods without rainfall, all trees need extra water. Mature trees with established root systems can go weeks without rain or supplemental watering. While they can cope with dry weather, they will be better off if you water them once a week.
The amount of water that a tree needs depends on its root spread. To estimate your tree’s root spread, use a yardstick to measure the tree trunk’s diameter. Take this measurement at least four feet above the ground. Trees should receive about 10 gallons of water per week for every inch of their trunk diameter. For example, a tree with a 10-inch diameter would need 100 gallons of water per week. Roots grow approximately 18 inches per year, so that water will increase over time.
The best time to water is early to mid-morning or early evening, especially when it’s hot outside. This allows the water to percolate into the root system instead of evaporating in the heat.
Mulch around your trees, especially newly planted ones, to optimize water uptake. An organic mulch will act like a sponge, holding water and slowly releasing it to the plant. This helps prevent evaporation, allowing trees to soak water even in hot, dry weather.
For the best results, apply a three-inch layer of mulch around each tree. Not only does this assist in water consumption, but it also helps control weed growth, insulates the soil from extreme temperatures, and improves soil health by increasing microbial activity.
Be careful not to add more than a three-inch layer of mulch because this could cause root suffocation and rot. Contact us for more summer advice.
From questions to estimate requests, contact us about your residential or commercial project.
