Spring is in full bloom here in the Chesapeake region!
To me, the colorful burst of tree buds means it’s time to start seriously thinking about my garden!
What do I want to plant? Will it grow in a container? Does it have the potential to be invasive? Will it promote pollinators?
Most importantly, when do I plant the seeds?
Most seed packets have a helpful map on the back of the United States planting zones. I live in Maryland, so I can plant my nasturtium in March/April (Figure 1). But growing up in Boston, that date was April/May.
Plant Hardiness Zones
These planting zones are largely based on the USDA Plant Hardiness Zones. The division of the US into these zones largely depends of the coldest wintertime temperature. In 2012, the USDA updated these maps, which resulted in a slight northward movement of these zones.
For example, my region switch from being 7a to 7b. In a way, this means that Maryland is now closer to being in Zone 8a than Zone 6b.
Connect to our Index
Remember last week’s post? We showed that the wintertime coldest temperature (TNn) has increased by 2.3°C over the last century (Figure 2).
This is the same climate change observation that helped support the changes to the USDA Plant Hardiness Maps.
One of the most common questions I am asked when presenting this project to the general public is “why do I care” or “how does this affect me”?
In this post, you just learned an answer: Changes to climate could mean changes to your gardening habits!
Whether this means you have to plant earlier, or maybe can try a new plant species that was traditionally a more southern cultivar….. anyone excited to start gardening has likely noted a change in our local climate!