This past growing season, we have seen a lot of ups and downs with the weather. Periods of hot, dry weather were followed by heavy rains and a few days of cooler temperatures. Do not be fooled by the recent rains, especially those that came as several inches in a couple of hours. Most of these heavy downpours do not infiltrate the soil, but rather run off and do not help with replenishing soil moisture.

According to the current Illinois Drought Monitor, a good portion of western Illinois and parts of central and extreme southern Illinois are experiencing abnormally dry to severe drought conditions. For the past several years, the fall months have been dry. This does not bode well for woody plants going into the fall and winter months — particularly evergreens such as pines, spruce and junipers, nor for broad-leaf plants like boxwood, rhododendrons and hollies.

Believe it or not, evergreens and broad-leaf plants do lose water during the winter. Plant roots can still absorb moisture up until the ground freezes. When we have those “February thaws,” or anytime winter temperatures are in the 40s and 50s with windy conditions, there is water loss. But plants can’t replenish that loss because any water in the soil is frozen. This results in the browning and scorching of the leaf margins or needles, much like we see during a summer drought. Add de-icing salts to the mix, and woody plants can become stressed going into the spring and summer.

Here are tips for how to help your plants going into 2023:

1. Keep watering. Continue to water your plants going into fall and up until the ground freezes. Depending on the fall and winter, that can be early or late. Don’t overwater, as you do not want to saturate the soil and then have that water freeze around the roots.

These conditions happened in fall 1991 when we had a very wet and mild fall followed by January-like temperatures. Plant roots were subjected to saturated soils, and then the water froze, damaging the roots. The next spring, many plants flowered, leafed out and promptly died. Their root systems had been severely damaged the previous fall, and they were not able to regenerate new roots.

2. Mulch well. Mulch around the base of your plants, preferably out to the dripline, with 3 to 4 inches of organic material. The mulch will help preserve soil moisture, mitigate extremes in temperature fluctuation (which are becoming more frequent and common) and provide important organic matter, which contains key plant nutrients.

Additionally, mulch will help recondition the soil, resulting in good soil structure and reducing soil compaction, particularly under trees that have experienced heavy vehicular or pedestrian traffic.

3. Don’t fertilize late. Avoid fertilizing in late fall, as this will promote new succulent growth that will not be mature enough or have hardened off to withstand a fall freeze or frost. The young tissue will either be damaged or killed and provide entry for pathogens and insects; plus, it is a waste of energy by the plant.

4. Offer wind protection. If you have evergreen or broadleaf plants growing in windy, exposed areas, especially to the west and northwest, consider installing a wind barrier to protect them from cold, desiccating winter winds. Barriers can be constructed from burlap and other materials that help block the wind and then can be dismantled in the spring.

5. Scout for D’s. Conduct a thorough visual inspection of your woody plants and identify any broken, diseased or dying plant parts — or as we say, the three D’s: dead, diseased and dying. These are parts you will want to prune out later during the dormant season. Make a mental note of them or mark them in some way for future reference.

Healthy plants going into the winter months will fare much better by being able to withstand the fluctuating winter temperatures, winds and moisture regimes, and will also be in a better position to resume growth in the spring. Our woody plants can be pretty resilient, but sometimes they need some additional TLC.

Miller is a horticulture professor at Joliet Junior College in Joliet, Ill., and a senior research scientist in entomology at The Morton Arboretum in Lisle, Ill. Email your tree questions to him at [email protected]. The opinions of this writer are not necessarily those of Farm Progress/Informa.