Record Breaking Heatwave & Your Garden: Part One- Microclimates

According to the National Weather Service, parts of Arizona and Southern California are expected to reach temperatures between 113 and 117 degrees today. Death Valley is expected to hit 122. I'm seeing posts throughout my social media pages from friends within the US with triple digit temps. So, what does this mean for your garden? Is it a death sentence? Well, it could be but, with a little preparation, the right plants and daily check ups-- your garden can still thrive throughout the summer months. Today, Central Florida will be topping out at about 97 degrees but, that 97 is an overall average for the area. Different areas can actually be hotter or cooler depending on environmental factors.

Considering our vegetable plants are in full sun, that is a lot of heat. We've already started making heat preparations in the garden but we still have a ways to go. Since, this will be information overload, I am splitting this information into separate posts. Today, we will talk exclusively about microclimates in your garden.

"A microclimate (or micro-climate) is a local set of atmospheric conditions that differ from those in the surrounding areas, often with a slight difference but sometimes with a substantial one. The term may refer to areas as small as a few square meters or square feet (for example a garden bed or a cave) or as large as many square kilometers or square miles."  

-Wikipedia contributors. (2022, June 4). Microclimate. In Wikipedia, The Free Encyclopedia. Retrieved 17:25, June 15, 2022, from https://en.wikipedia.org/w/index.php?title=Microclimate&oldid=1091496577 

So, let's try to put this into the simplest explanation possible. You are standing in the direct sun. It is hot. You see a tree casting shade onto the ground. You move into the shade. It is 5-10 degrees cooler. That is a form of microclimate.

Now, let's take it a step further. Imagine two walls on either side of the tree that creates an alley way. The wind moves down the alley way creating a wind tunnel, cooling the area off even more like in one of our local parks. The park also has a water feature wall. Now, imagine the wind picking up the spray from the water wall and it blows on you under the shade tree. That is a refreshing microclimate that could make the unbearable quite pleasant. Now, think of your tomato plant being you and the fountain spray breeze shade tree is your garden. I know what you are thinking. Your backyard doesn't come equipped with shade from a tree, a water feature wall or a wind tunnel. However, you can create spaces in your garden to give similar effects.

We use tall, heat loving plants (okra, corn, malabar spinach) to filter direct sun on plants that cannot take the heat. We plant in rows, on trellises, running East to West. One part of the plant will shade the other part at different times of the day. With the addition of shade cloth, you can create an instant microclimate; continue to research microclimates and implement multiple ideas. My tomatoes are planted next to the house in a wind tunnel. It gives me a 5 degree difference. By adding shade cloth over the top and with the corn growing in the front of the row, I can drop the temperature about 10 degrees. That could be the difference in my tomatoes blossoming or stopping production entirely. 

I have walked around our little downtown area and taken some photos to show as examples of some microclimates in my immediate area. Some are natural and some are manmade. For your homework, go out and do the same. Do it in a nearby park, your neighborhood or even your yard. For extra credit, use a thermometer to see the actual differences. In your gardening journal, note it all down. If you have any questions, let me know!