Feels like summer out there, doesn’t it?
Well, not anymore. Last week (March 19-23) we had record warm temperatures, peaking in the 80’s. Every day as I walked about various landscapes, another tree species was blooming; red maples popped, then crabapples popped, then magnolias, then cherries. Forsythia is in full bloom, and several other shrubs started to leaf out or show their flowers. Wintermoth had also hatched, as was evidenced by the very fine silken strings left behind on the twigs of host trees, going from bud to bud where they are now feeding. I found a couple of larvae- they are smaller in diameter than a thread and about 1 millimeter long. But they are out there.
Monday night saw temperatures drop into the low 20’s. Not good for all these new flowers and leaves out there. This morning, I stopped to look at a star magnolia in Wenham- it was in full bloom, except the flowers were wilted over, and they felt like slush. Frozen. They likely will fall off the tree in the next day or so, barely enjoyed in such a brief glimpse of summer.
This cold snap may cause similar damage to many other landscape plants, but only time will tell. Like a plant getting defoliated by wintermoth caterpillar, it will need to reproduce foliage if it’s current leaves were frozen beyond repair. A healthy plant can handle this every now and then, but if your plant has been weak and had started pushing out new leaves before yesterday, the cells in tender young foliage may have been irrepairably damaged. A similar situation occured 2 years ago, when we were hit with a late frost in April- I saw many Japanese maples turn brown at their outermost branches. It was a temporary condition, but it did warrant a number of phone calls. I think I can expect the same this spring now.
Will this little freeze kill off winermoth? Not sure yet. The cold certainly does slow down insect activity- no bees flying about, or other insects moving very much today. Wintermoth overwinters as an egg on the trunk of a tree and can handle the cold winter, but not sure how a newly hatched larvae will handle it. Again, time will tell.
If you need an evaluation of your landscape, I am available, just contact me at firstname.lastname@example.org.