This year has been a bit unsteady regarding growing conditions for many plants. I have been getting a lot of questions regarding the death in many plants this spring and the lack of growth in many of our plants as well. I wanted to take this time to go over this issue with all of you.
This spring we have been seeing quite a bit of dieback on many different perennial plants and shrubs. Roses and spireas are suffering from what we call winterkill. Winterkill occurs commonly in the winter months when plants are exposed to cold, drying winds. The winterkill was extremely hard on these plants this year and has caused the tops of them to die. What we are seeing in our landscapes is plants that only have leaves at the bottom of the plant with no leaves and brittle branches at the top of the plant. Many other shrubs are experiencing the same problem. These dead branches can be pruned out of the plant. If the plant affected was a rose, it could have more problems if the dieback occurred below the graft union that many roses posses. If it died below the graft union, it should be replaced with a new rose.
We are also seeing a great deal of loss in willow trees. Many willow trees, throughout the state, are dying entirely or losing the top or many branches throughout the tree. This is attributed to many years of tough growing conditions. In 2012 our plants faced severe drought and three weeks of temperatures in the 100’s. This is very hard on our plants and it takes 3-5 years of normal growing conditions for a plant to recover from a drought like this. This drought was followed by the winter of 2013-2014, which was very dry, cold, and windy. That winter caused many of our plants, especially arborvitae, to die due to the desiccation they faced. Finally, we have had a very uneven warm up this spring that followed a quick drop in temperatures last November, when temperatures fell to only 5 degrees Fahrenheit.
It is very hard on plants to go through so drastic extremes during their growing season and to have it hit them for multiple years at a time. This is the reason for so much death and dieback in so many different plants.
A lot of our plants are also very slow to warm up this spring. Butterfly bush, privet, hibiscus, and beauty bush have still not broken dormancy this spring. We at Nebraska Extension are suggesting waiting until the beginning of June before giving up entirely on these plants.
Many of our vegetable plants, if they have already been planted, may not be growing very well at this point. They are slow to grow well in this cool, cloudy weather. They will catch up when it warms up.
Keep an eye on all of your plants for diseases that are sure to be a problem with this weather. Leaf diseases and fruit diseases could be a problem this year as many are common in wet, cloudy weather. Watch leaves for leaf spots to remove those leaves as soon as you begin seeing a spot on them. When you need to water, be sure to water your plants from the bottom rather than overhead to reduce spreading these diseases.