It’s hazy, hot, humid, and all around uncomfortable for humans, animals, and plants alike during summer heat waves.
With increasing extreme weather patterns due to climate change, heat waves are becoming more frequent throughout the globe.
While you may wilt in abnormally hot temperatures, there are things you can do so that the plants in your garden survive and thrive through extended heat.
In this article, we will go over effective and regenerative gardening methods that will help to protect your garden even in triple-digit temperatures.
A heat-proof garden begins at the soil level, which is where regenerative practices come in.
Let’s dive into each of these key components to your garden’s ability to survive high summer temperatures.
Regenerative gardening techniques will help your garden to fair better during excessive heat.
1. Fast working - Mulch.
Mulch offers so many solutions - water retention, soil shade, temperature reduction - mulch really has it all.
For maximum protection from heat and soil evaporation, I’d recommend organic straw. I’ve had lots of luck with this material during hot weather, even through stretches of 118-120 degree F weather.
The light color of the straw helps to keep the soil cool, which in turn prevents evaporation.
I’ve found that chopping the straw helps it to go further in the garden. Spread it over the garden around your plants as thickly as you can.
If you don’t have access to organic straw or organic hay, a light covering of grass clippings can also do the trick. You want to make sure that the grass clippings have rested for a day or two so that they release any heat from early decomposition.
Mulch is something that you can add to your garden right before the heat comes, and so it’s my number one pick for helping your garden survive extreme temperatures.
2. Fast-working - Water in the morning.
In preparation for the high temperatures of the day, water your garden early in the morning daily during the duration of the heat wave.
PennState Extension says that when gardens are watered well in the morning, the soil temperature decreases and helps plants to survive warm afternoon heat.
3. Longer-term - No-till regenerative gardening techniques. No-till and other soil-building methods help the land to hold and store more water. When the soil is healthy, there is less evaporation over-all, meaning that plants will still have access to water during periods of extreme heat.
According to the [Environmental and Energy Study Institute](https://www.eesi.org/articles/view/no-till-farming-improves-soil-health-and-mitigates-climate-change#:~:text=No-till farming can build,more resilient to extreme weather.), no-till farming means that less weed pressure happens over time. Less weeds means less water competition for your crop plants.4. Longer term - cover crops. The University of Nebraska-Lincoln recommends the regenerative strategy of cover cropping to help reduce water evaporation and increase the resiliency of your soil and plants.
This is because the biomass left over from the cover crop, when left on the soil, acts like a mulch to prevent damage from heat, water loss, drought, and flooding. Like mulch, cover crop green material keeps soil temperatures low.
4. Longer term - organic fertilizer for healthier plants.
PennState Extension mentions that when plants have access to the nutrients they need, they are more likely to survive extreme temperatures.
While I wouldn’t fertilize plants directly before, during, or directly after a heat wave, proper preparation earlier in the season can help your plants to thrive. Healthier plants are more likely to have less damage due to heat, whereas struggling plants have a disadvantage going into high temperatures and are more likely to be damaged.
Organic fertilizer is important, as it builds soil health and encourages plants to maintain their relationship with the soil microbiome. Synthetic fertilizer by-passes the soil microbiome delivery of nutrients, and damages soil health.
5. Longer term - grow heat sensitive summer plants in sunken beds.
A system of beds that are lower than the surrounding ground is an Indigenous practice that has supported tribes such as the A:shiwi of Zuni Pueblo in New Mexico. According to a publication by the Smithsonian National Museum of the American Indian, the beds look like they are sunken, but they are actually surrounded by small berms, so the surrounding area is elevated.
Hayes Lewis, of the A:shiwi Nation, shares that “The elevation at Zuni is approximately 6,800 feet above sea level. Since it is semi-arid, there is not much rainfall. Whenever there is rain, it needs to be captured, which is why berms - raised mounts of earth - are built up around each plant.”
Also known as a “waffle garden,” these beds resemble the indented pattern of your breakfast Eggo.
If you regularly experience heat waves, it is worth it to purchase seeds that are bred to handle heat and drought conditions.
Dixon Garlic (for over-winter growing but is noted to be able to handle spring heat)
If it’s available to you, installing a drip irrigation system will allow the water to do its job better - to permeate the soil and get to the roots of the plants. Because it is so much more efficient than overheat watering, drip irrigation systems help to save precious water throughout the summer months.
Regardless of what kind of watering system you have, deep watering is always best when compared to surface level quick watering.
As we mentioned earlier in the article, watering in the morning is best for plants to prepare them for the day’s heat.
A quick way to provide shade is with shade cloths. Shade cloths allow some light to come through so that the plant can still engage in photosynthesis, but helps to reduce overall sunlight and temperature conditions.
You can purchase shade cloth in large quantities, and cover your whole garden with it if you have a fenced in area, propping the cloth over the borders of the fence.
You can also purchase shade cloth to go over your greenhouse, which can really help with tomato ripening, since tomatoes pause their maturity process when temperatures are too high.
A more long-term way to provide shade is with trees, bushes, and shrubs. A food forest is a great permaculture-based solution to hot weather.
High temperatures stress out the cell walls of the plant, and can cause any water held in the soil and within the plants to evaporate.
Furthermore, plants aren’t able to go through the process of photosynthesis during high temperatures. According to the University of Delaware, photosynthesis slows down once temperatures reach 94 degrees F.
This weakens the plant, drains energy stores, and prevents nutrient uptake.
After a heat wave has come through, here are some things you can do to help your plants to recover:
Discover how agroforestry can regenerate land and help withstand high heat
