Drought plus cold meant a deadly year for these trees. Here’s how to save the rest

It’s the unofficial start to summer. For most of us, Memorial Day weekend, not the summer solstice on June 21, marks summer’s arrival. Let’s assess the past spring. As the old saying goes, “It was the best of times, it was the worst of times. “

While there has been sporadic rainfall in the metro, overall the drought conditions of 2022 continue into 2023. However, the Kansas City area is faring better than southern and western Kansas and much of Missouri.

The lingering effects of the hot, dry summer of 2022 are evident. Drought conditions have taken their toll on evergreens.

Arborvitaes, spruce and pines have died coming out of winter. These non-native species are not tolerant of prolonged drought, which causes random die-back of limbs, thinning of the canopy or, in many cases, death of the tree.

Once symptoms appear, little can be done to reverse the effects. Dealing with dry conditions requires proactive watering. Evergreens susceptible to drought should be deeply watered about once a month, while younger, less established trees require watering more frequently.

Deep soaking involves turning the hose to a slow trickle and allowing it to run for several hours in numerous locations around and under the tree. A sprinkler can be left running for most of the day. Don’t fall into the trap of believing lawn sprinkler systems will save trees. Sprinkler systems are set to provide frequent, less deep water. They are designed for lawns, not mature spruce.

Winter’s wrath

Overall, we experienced milder winter temperatures with exceptions. An early fall cold snap damaged many plants before they became dormant. Christmastime brought two periods of near-zero cold snaps, which also caused damage.

The effects of sudden cold could be noticed in several ways. Many plants didn’t fully leaf out this spring. Weigela, deutzia, butterfly bush and Japanese maples experienced random branch die-back. The good news is that many of these plants generated new growth from the base or more mature limbs.

Prune out the deadwood, and given time, most should recover. Unfortunately, some have died. The leading cause of death is the combination of drought and cold. Plants under stress are less hardy and more likely to be damaged by winter conditions.

The other effect of winter and the drought was poor flowering. Many plants — such as azaleas and forsythia — had fewer blooms. The cause was the combination of the hot, dry summer and winter cold.

Many spring flowering plants set their flower buds in late summer. Stressed plants set fewer buds, and rapid temperature changes can kill additional flower buds.

As we move into summer, what can we do? We cannot control the weather. If the drought continues, act proactively: water plants most at risk, such as evergreen trees, shrubs and new plantings. Deciduous plants give us signs of stress by wilting. Evergreens don’t show the symptoms until it is too late.

Will summer be hot, dry, wet or cool? Will we be dealing with heat and drought? We never know, as we live by the motto, “If you don’t like the weather, give it a day and it will change.”

Dennis Patton is a horticulture agent with Kansas State University Research and Extension. Need help? Contact the Johnson County Extension gardening hotline at 913-715-7050 or email garden.help@jocogov.org.

This story was originally published June 2, 2023 at 6:00 AM.