It’s no secret that 2020 has been a stressful year for pretty much everyone. People aren’t the only ones feeling the stress – trees are, too.
One culprit is dry weather. According to the National Integrated Drought Information System, 67 percent of Minnesotans are living in abnormally dry areas, including those in Hennepin, Wright, Stearns, McLeod, Meeker, and Kandiyohi counties.
Another culprit in many of those same areas has been storm damage.
Pests can also contribute to a tree’s stress level.
A telltale sign of stress is called dieback, when leaves drop off earlier, which was common even when it was still summer.
While damage can be addressed by trimming away the affected branches, water and mulch can help reduce stress for trees now and for the winter season ahead.
There are many different watering methods.
For newly planted or very young trees, consider a watering bag, which decreases the chances of both over-watering and under-watering, helps establish roots, and reduces runoff. Watering bags are ideal for northern climates, but must be removed before winter.
They may be bought or created at home. An alternative is using a 5-gallon bucket with a hole drilled into it.
Every week, trees should receive 10 gallons of water per inch in diameter.
Drip irrigation utilizing tubing to drip water to roots is also an efficient way to water trees up to 7 inches in diameter.
Soaker hoses allow water to seep slowly and evenly into the soil and roots below. They prevent water from being wasted by evaporation, make soil moist but keep it from becoming waterlogged, and help to minimize root rot and other water-related diseases. Store-bought soaker hoses have many tiny holes in them, but one can be made at home by creating holes every few inches of a hose.
Bubblers attached to a sprinkler system also have similar benefits of a low-pressure stream of water directly to the roots.
Speaking of sprinklers, for mature trees, overhead sprinklers work just fine. They water the entire root system, which is typically in the top 12 to 18 inches of soil and spans the entire area under a tree’s canopy or slightly beyond, especially for coniferous trees like pine and spruce. They do cause more runoff, though.
All watering, especially with sprinklers, should take place between dusk and dawn, when the roots can best absorb moisture.
If the ground is sloped, water more often for shorter periods of time.
To test if enough water is being applied, dig down 6 to 9 inches at the edge of the canopy. If the soil is cool and moist, the tree is getting enough water.
Making sure trees get enough water before the ground freezes is imperative, especially for evergreens.
Note: Avoid watering the trunk, as it is not efficient and may lead to decay or fungus that would actually hurt, and potentially kill, the tree.
Mulch is important because it helps prevent runoff, decreases evaporation, minimizes weed germination and growth, protects trees during cold winters, and improves soil health overall.
It is especially helpful when paired with a soaker hose.
In order for it to be effective, it must be used the right way.
It’s not uncommon to see mulch packed right up against trees. That is not the proper technique, however. In fact, doing so can actually stimulate fungus growth, attract pests, and reduce oxygen for roots.
It should be about 3 inches thick either all the way out to the edge of the canopy or up to 8 feet, whichever is less.
To determine how much mulch is needed, use an online mulch calculator.
Replenishing the mulch annually is a good idea. It will prevent weeds, provide nutrients, and assist with drainage.
Watering helps reduce stress and prevent against myriad problems.
Mulch makes watering more effective and prepares trees for the winter months ahead.
Together, they are the perfect combination, especially during these dry, fall months.