PLANT HARDINESS ZONES SHIFT: what does it mean for local gardeners? Our landscaping expert Mary Anne shares her advice:
“The 2023 USDA hardiness update moves Louisville and the majority of KY up slightly into Zone 7A based on average temps over the last 30 years (1991-2020). Moving from 6B to 7A indicates a slight change of average temps in a 0-5 degrees Fahrenheit range. Additionally, Jefferson County is nearly surrounded by Zone 6B; moving outside of Jefferson Co. North, East or West are largely still Zone 6B with the exception of moving South into Bullitt County which is now Zone 7A.
As a gardener, this means I will be paying close attention to where I am sourcing my plants. Am I purchasing from a nursery that has grown stock locally, or procured stock from other parts of the country? It also means that while temps are on average higher, weather is still unpredictable…so keep an eye on your weather app for severe freezing temperatures and drought. I might feel more comfortable planting stock that is slightly less cold hardy, but if temps drop severely or remain low for extended periods, those plants will need special attention and insulation to be best protected. This could look like heavy mulching, covering with leaves, or insulating with cloth or plastic.
Mostly, this means the easiest choice you can make as a gardener is planting native plants that have been grown locally. Native plants grown locally are already adapting to our changing climate and will be the most reliable choices for hardiness and adaptability.”
