Winter Watering

winter desiccation of white pine

We don’t think about our outdoor plants much in the winter months. Once plants go dormant for the year many people believe that they need nothing until spring, but that isn’t the case, especially in years with low or no snow or rain throughout the winter months. And this year it has been very dry with little snow cover. The Beatrice area has only received a little over 1 inch of precipitation since October, compared to just over 3 inches in normal years. 

Winter Watering

Precipitation is needed for our plants all through the year. If they aren’t receiving that through natural precipitation, we need to help them out. Make sure your plants are well-watered going into the fall. Also, water throughout the winter when the ground is not frozen to help the trees through a dry winter, if necessary. Winter watering should occur near midday on days when the temperature is 45 degrees or above and is only necessary 1-2 times per month until spring. Currently, the ground is not frozen and we have been receiving quite a few days above 45 degrees. It is a good idea to test for soil moisture with a long screwdriver or soil probe prior to watering to determine if watering is necessary. If the screwdriver goes into the soil easily up to 18 inches, watering is not necessary. However, if pushing the screwdriver into the soil becomes very difficult after the first couple of inches or less, watering would be necessary. After watering, apply a light layer of mulch over the roots.

Winter Desiccation

Winter desiccation commonly occurs on evergreen types of trees and shrubs. All trees are still transpiring or losing water throughout the winter months. Evergreen trees are transpiring at a higher rate than deciduous trees. Winter desiccation occurs when the amount of water lost is greater than the amount of water the tree takes in throughout the winter months. The damage from winter desiccation is brown needles out on the ends of branches. However, the damage from winter desiccation will not usually show up in our trees until early spring, they tend to stay green through the winter. Drought effects can damage deciduous trees as well, but it is less common. The trees and shrubs most susceptible to winter desiccation are those that were planted in the past year or two. Winter desiccation is shown in the photo above.

Watering through the winter will help reduce desiccation damage. The damaged areas can be pruned out in the spring but give the plant time to fully come out of dormancy before pruning out brown or yellow areas in evergreens. Even if the needles are damaged, the buds may still grow, pruning too soon will remove those buds. It is best to wait until later May before pruning out winter damaged areas.

Winter Irrigation on Turf

Turf can also benefit from winter watering. Home lawns are more tolerant of winter desiccation stress because our home lawn species have deep roots but they may still need some irrigation in very dry years. Established lawns may not need winter watering, but newly planted lawns may be more susceptible to winter desiccation. However, as we are facing a dry winter with little to no snow cover, irrigation may be needed at low amounts. Ensure that winter watering is not through an irrigation system or it will need to be cleared out again before nightfall so the pipes don’t freeze and burst. It is best to hand water with a hose in the winter months. When watering in the winter, be sure that the hose used is removed from the spigot after irrigation to avoid freeze damage to the spigot and to avoid water in the house and be sure to drain the water from the hose to avoid damage to the hose. If you have a newer type of retractable hose, you could remove it from the spigot after watering, drain the hose, then roll it up and place it in the basement for storage. Again, make sure the soil is not frozen and temperatures are above 45 degrees. Irrigation, if needed, should only be applied twice per month and only at a half an inch each time you do water.

This article was reviewed by John Fech

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