So it's that time of the year. Fall is here, pumpkins are being carved, Halloween is on the horizon and this season frost is expected a lot earlier than usual.
My farmer intuition is not surprised though. I think of the weather in terms of averages. If we had a mild winter, it only makes sense that the spring will be colder than normal, which it was in 2022. Our summer made up for our lousy spring by being hot and dry. A fig tree's dream. And now, I'm not surprised that our fall would be short and winter would come early. Here's what to expect when you have frost in the forecast:
First of all, lets think of frost into two categories:
Light frost and hard frost.
Light I define as something around or above 28F with a frost that's short in duration. A hard frost is something that is around 25F and below combined with frost that has an extended duration. It's important to understand that the duration of frost is critical, but the same can be said about the temperature.
A light frost which is what I'm expecting here in the Philadelphia area, will be extremely mild and it'll seem like almost nothing happened. We're not even likely going to see a temperature below 32F in the coming nights, but you can still see frost above 32F. Typically these light frosts do no damage to the leaves and only minimally impact their time till dormancy. A light frost can actually be a good thing because it'll speed up the ripening of our fruits remaining on our trees that are swelling. Our figs ripen very slowly this time of year because it's so cold outside. That frost helps quite a bit and to me is a welcomed sight to help me ripen my very last fruits of the year and often they'll actually be pretty tasty. Now if they weren't in the final ripening stage or they're lower on the tree and untouched by frost, it'll be very similar to what happens to the leaves. Almost nothing.
A hard frost like some of you may be seeing in the South has totally different repercussions. At around 25F and extended periods of frost, you'll very likely see the leaves on your trees turn brown the following morning. Over the following days the leaves will fall from the trees and this will certainly set your tree on a path towards going to sleep for the winter. The figs that are swelling will continue to ripen, but the green and hard figs not in that final ripening stage can fall off the tree along with the leaves.
So there's quite a big difference depending on what you'll see in your yard.
In terms of the health of our trees, a light frost does almost nothing negative. A light frost can burn the tips of our branches if for some reason your trees haven't gotten the hint that winter is coming and they are still growing. Usually these are trees getting too much soil moisture.
A temperature of about 20-25F can burn the trees a bit further than just the tips if the growth is not lignified to the level that they should be. Green and hard growth is usually fine, but the more green the branches are, the worse their ability is to withstand lower temperatures. At about 20F you'll very likely see damage on mostly green but hardened wood. Usually about 4-6 inches in length, so prepare to take cuttings accordingly.