Prepare plants for winter temps with proper planting, irrigation

Welcome to fall.

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The recent cold temperatures had me and other gardeners scrambling to get houseplants back inside, and maybe seeing the last of the summer flowering plants until spring.

These temperatures are just a hint of what is to come.

Every winter, there is a chance of getting cold enough weather to damage plants in the landscapes.

However, there are management practices to reduce the chance of cold damage to plants, and now is the time to use these practices to help plants this winter.

The best way to prevent cold damage to plants is to select a plant that can tolerate cold temperatures. When buying plants, check the tag or look up the plant in a plant book to determine the minimum temperature that it can withstand.

In addition to looking at the cold temperature that the plant can withstand, think about the heat index of the plant as well. Will it survive summer? This area will fall into the plant zone of 7a or 8b.

In addition to plant selection, think about the microclimate of the yard.

Every yard has areas that are hotter than others and colder than other areas. During the winter, the north and northwest facing of a yard will be the coldest. The south facing will be the warmest area.

Why is this important? When planning where to plant, put the least cold-hardy plants on the south side of the yard. These plants will do better near a house or buildings, because the buildings hold heat and this keeps the temperature around these plants warmer. Plants that are cold-hardy can be planted in other areas of the yard.

Also, survey the yard for low spots and high spots. Cold air sinks, and low spots will be colder than higher spots in the yard. Flowering plants and fruit trees need to be planted in higher areas to keep from losing the flowers and fruit.

Other features to look for are windbreaks and shade. Wind can dry plants out and increase the chance of cold damage. In the winter, the coldest winds come from the northwest, so reduce the chance of cold damage by planting beside fences, buildings and taller plants. Windbreaks are most useful in reducing injury during a cold air mass.

Plants that are grown in shade are less susceptible to cold damage, because the canopies above the plants help reduce the radiant heat loss to the atmosphere. However, if a plant grows better in full sun, the stress from the shade will make the plant less cold-hardy.

Plants that have the proper nutrition levels and moisture levels have a better chance of surviving freezing temperatures. Fertilizing plants at the proper time of the year will give the new growth time to harden off before cold weather arrives. Plants that are fertilized too late will put on new growth, and this growth will not have time to harden off before cold weather arrives. All fertilization should be done before August.

Also, plants need adequate water to help survive cold temperatures.

Plants continue to have water requirements during the winter months, so check the moisture level around your plants before a cold snap and water if necessary. Moist soil absorbs more heat which helps to maintain an elevated temperature around the plants.

During the winter, if we haven't had any rainfall in a two- to three-week period, irrigate your plants. A mulch layer 3 to 4 inches deep around plants will help conserve moisture and maintain higher soil temperatures and protect the root system.

If we have a sudden freeze or extended cold period, the damage to the plants might not be evident for several weeks or months, so wait to see the amount of damage. After determining how much damage was done, prune out the damaged areas. If you have severe damage to certain plants, you should think about moving these plants to another location and replacing them with more cold-hardy plants.

Charles Phillips is a retired Columbia County Extension Service agent and operates Hort Consulting. He can be reached at cphillipshort@comcast.net.