Of all of the browning evergreens this winter, this is the group that most surprised me. I had never seen damage as extensive as this to Junipers in my 35 years of observing woody plants. These are usually very tough durable plants and can take any winter that Mother Nature can throw at them.
This past season was different.
Junipers are one of the latest growing conifers if not the latest growing conifer in our area. My theory is that the dry September in combination with the warm moist October and November, followed by the quick, dramatic freeze-up in late November and early December caught many of the Junipers before they could get fully prepared for winter. I think this is why we see many plants with brown tips on them this spring. This foliage wasn’t completely hardened when the winter hammer came down.
There were considerable differences between cultivars in our nursery. We only field grow Upright Junipers so those are the ones I assessed most extensively. Those cultivars which were most severely burned were: Juniperus virginiana ‘Burkii’, Juniperus virginiana ‘JN Select Green’ — Emerald Feather™ Juniper, Juniperus virginiana ‘Cupressifolia’, Juniperus chinensis ‘Hook’s #8’, and Juniperus virginiana ‘Glauca’. Some others at the nursery had spotty tip die-back but not as severe as the cultivars I have mentioned. Young plants that weren’t under the snow were particularly hard hit. They are often the last to stop growing and don’t have as deep of roots as the big guys. At least that’s what I think explains the difference in burning.
I noticed extensive browning evergreens in landscapes around the Milwaukee area on Juniperus virginiana ‘Canertii’, Juniperus sabina ‘Sea Green’ — Mint Julep Juniper, Juniperus chinensis ‘Pfitzer Compacta’, Juniperus chinensis ‘Pfitzer Glauca’, Golden forms of Juniperus chinensis and several other cultivars I couldn’t identify. I suspect a lot of this damage had to do with the locations of the plants or late pruning because I also saw specimens of these plants that had little to no burn.
The native Juniperus virginiana — Eastern Red Cedar growing along roadways throughout Southeast Wisconsin were impacted to various degrees by the winter. I observed browning evergreens that were burned completely on their outer extremities while others nearby were just fine with little to no burn. I suspect there is genetic variability among seedlings of Juniperus virginiana in their ability to withstand such a winter. Salt spray also likely played a large role in the damage to these roadside plants.
It looks like the junipers were just damaged on the outsides of the plants and can be easily fixed up by shearing off the burnt foliage.