- Author: Mark Bolda
We have a stretch of unusually cold weather, including freezing temperatures at night, underway currently on the Central Coast, and it has attracted a lot of attention.
Being originally from Wisconsin, it always slays me what people here think of as cold. I was up in Cupertino this morning, and overheard a women exclaiming into her phone that it was so cold that she was wearing two jackets!! Ever hear of a snowmobile suit, longjohns or a ski mask? I used to go running in -10 degree weather, and fished through the ice all day long in temperatures even colder. Naah, 25 degrees above zero isn't cold my friends.
Regardless, I should provide some insight to you here concerning these upcoming freezing temperatures and what they could do, particularly in the case of strawberries, which in most places around the Bay have started to really grow and in some case produce a lot of fruit already.
Strawberries come from temperate regions of the world and can handle freezing temperatures in due course. However, once the plants are actively growing like they are here now, that does present some difficulties which growers and managers can take some steps to address.
Once the strawberry plant has broken dormancy, cold temperatures no longer offer any enhancement in the way of cold conditioning (what many of us refer to as chill), and therefore we shouldn't be seeing any extra plant vigor or fruiting from these freezes.
To the contrary, while these early spring freezes will normally not kill strawberry plants here on the Central Coast they nevertheless present a setback to fruiting because of the danger they present to sensitive plant parts. The core of the strawberry plant, which is the crown and is a thick, fleshy organ full of water and if correctly planted is mostly submerged below the surface of the soil, is well protected. Not so with flowers and on occasion younger leaves, which are fully exposed to the cold and can die back in a hard freeze. Even if a flower is not killed outright by below freezing temperatures, pollination has a good probability of being affected and subsequent fruit will be misshapen.
Growers can take measures to mitigate the damage of freezes to strawberries. If one is concerned about an upcoming freeze, taking the step to saturate the bed full of water via the drip irrigation before the frost is expected can do a lot. Having the bed full of water accomplishes two things; the first is that the irrigation water being well above freezing will insulate the bed, and second the cells of plant in a well watered condition will become turgid with liquid and this to some measure protects them as well against freezing.