Posted by Mary Small, Jefferson County Extension
Walking through my community is not only good for my health – it’s also a great time to scout for plant problems, take pictures and post them here!
|Arborvitae with desiccation injury|
This arborvitae is a good example of fall/winter injury. Our dry, warm fall contributed to the problem. Needles can still transpire (lose water) on warm, sunny and windy days. If there’s no water reinforcements, needles dry out.
The damaged side faces south so it’s also possible the tissue was not acclimated in time for a cold weather event. It’s also possible the tissue on the south side warmed up, activated cells and then temperatures dropped rapidly, causing the cells to freeze. Oops.
|Junipers with desiccation injury|
Down the street I found a grouping of junipers that met a similar fate. These face west and are planted next to the foundation. I think the plant tissue warmed up because of the warm western exposure and was likely damaged at the same time as the arborvitae. The foundation area is a typically dry site in a landscape; there may not have been enough water for the plants to replace losses, either. That light colored stone mulch reflects heat onto plants, too. Oops.
Both sets of injury emphasize the importance of two practices – siting correctly and fall watering. Narrow leaved evergreens are prone to needle damage in dry fall and winter weather, so it’s important to plant them in a location that affords protection from temperature extremes. South and west exposures do not. Evergreen roots can still absorb moisture well into the fall as long as soil temperatures are above 40 degrees F. Monthly watering around November 1 and December 1 can go a long way to help supply needed moisture and decrease the injury.
Oops is one of the few things I said when I saw this poor willow. We had a strong windstorm and this section of the community was particularly ravaged.
The raggedy wounds should have been trimmed to be more circular – that would help promote wound closure. But the real problem is that the tree was a poor selection, being a weak-wooded species that breaks up easily in wind. It wasn’t trained while young to improve its form and now it’s too late to do much about it. Sometimes a tree just needs to be removed when it is the wrong plant in the wrong place.
|Don't leave stubs!|
Finally, what is this crabapple “pruning” job all about? Leaving a stub is never a good idea. It eventually decays and can be an invitation to insect and disease problems. Oops. (Good thing I took the picture when I did –the tree’s since been removed!)