Has your garden been languishing? You are not alone. I hesitate to think of any year of gardening weather in Alabama as “normal,” but this spring most certainly wasn’t it. After planting season, the weather insisted on dropping into the 40’s at night — repeatedly — and refused to climb into the 70’s. Our summer garden plants need warmth to grow and thrive, and we didn’t get that weather until around the beginning of May. Since then, my squash seeds have finally come up and my tomato plants seem to be growing almost fast enough to see. With our long growing season, these plants will have plenty of time to produce fruit. Meanwhile some of the cooler season crops, like radishes, got to enjoy a longer season.
How delayed plant development has been in your garden depends on your microclimate. My garden is in a colder microclimate area of Huntsville, while the Botanical Gardens lies in a warmer one. Although only a few miles apart, plant development between those two sites can easily be 3 weeks apart. Your garden could be anywhere in between — or even colder if you are on top of Monte Sano or Rainbow Mountain. Topography and other features can not just affect the temperature, but the humidity, wind speed and precipitation.
Within your yard, you also probably have at least a few tiny microclimates. A sheltered spot out of the winter wind, or next to a south facing stone wall, or even under a sheltering tree. You can use these spots to your advantage. People often look for sheltered and sunnier locations for plants that need more warmth, but the opposite can be true as well. A cooler spot my be a good location for plants which prefer more northern climes than Alabama, like rhubarb or raspberries. A low spot where the rain collects may be ideal for a plant that needs more moisture, and a harsh dry spot may be a good place for your sedum collection.
Getting to understand the microclimates on your property can be a long process, filled with plant victories… and plant deaths. It’s not an entirely passive process, nor is it fixed in time. Changes to the landscape near your home, natural or manmade, can change your microclimates, but as a gardener you can choose to specifically modify your landscape to create specialized zones. For example:
- Use structures like buildings and fences to block wind and sun
- Use high thermal mass materials, like rock and concrete, to store daytime heat that gets released at night
- Use taller annual or deciduous plants to create shade in the summer but let sunlight through in the winter
- Use mulches to retain moisture and moderate soil temperature swings
- Use temporary materials, like row cover, shade cloth and old glass windows to increase or decrease air temperature in a small spot
- Use containers to move plants to their ideal climate as the seasons change
- Use swales, ditches and impervious surfaces to move rainwater to where you want it the most
Humans have been using microclimate modification strategies to enhance their food production for thousands of years, and you can, too.