Gardening for extreme temperatures is not just about adapting to changing climates. It is about working to mitigate the effects of extreme heat through careful design and through the various different choices we make in a garden.
Understanding how plant choices and design decisions can increase the resilience of a garden in extreme heat is important.
One major thing that we need to do to create gardens that can stand the heat is to make the right plant choices.
Plants that are native to arid or semi-arid settings can often be good choices for high-heat situations as well as just dry ones. Understanding plants is important because this allows us to find ones best suited to particular locations in our particular gardens.
In extreme heat, plants lose more water. Some plants have specific adaptations which enable them to hold onto water more effectively during hot conditions.
Regardless of water availability, heat tolerance is another plant characteristic. Some plants can cope with heat better than others. So while in temperate climates, we may be more familiar with plant hardiness in winter, we also increasingly have to look at hardiness against summer heat too.
Often, we can use native plants, as these are best adapted to the conditions found in a particular location. But sometimes, as our climates warm, we might turn to native plants or regions historically a little warmer than our own.
Another way that we might go to create gardens that can stand the heat is in a direction that allows us to decouple somewhat from the conditions.
Growing under cover allows us to have more control over the environmental conditions, and we might even think about creating a closed-loop aquaponics system to produce food in more controlled conditions when the weather is hot outside.
In a well-ventilated space with a well-designed water-based growing system, it is potentially possible to grow a lot of food, even in areas where extreme heat would typically make this a serious challenge.
Of course, you do not need to de-couple from the environment to create a garden that can withstand the heat. Often, working with nature can be just as effective for food production and other sorts of gardening.
One important thing to remember as you strive to create a resilient garden is that everything comes back to the soil. With healthy soil, we have healthy plants and, when those plants are eaten, healthy animals, including people.
Understanding and improving the soil through keeping a living root in the soil for as much of the time as possible, avoiding tilling or digging, and using organic matter as mulches, are all important in creating a garden that can withstand heat waves in summer.
No dig gardens such as lasagna beds or hugelkultur mounds, humus-rich planting basins in rain gardens, waffle gardens, and more—plus all sorts of raised, mulched beds can help us to create gardens that can cope when high temperatures arise.
Shaded Vegetable Garden
Creating shade for key growing areas during the hottest parts of the year can be important. While, most of the time, in most temperate climate regions, full sunlight is required and desired for annual food production, it is important to remember that shade can often be beneficial in heat waves or in the hottest regions.
We can create shade in simple, obvious ways, such as using shade netting erected over frameworks over a vegetable garden area. We might also use a pergola or other structure covered with climbing plants, either annual or perennial, that offer the shade we need.
However, the best ways to create shade for hot summer conditions do not involve construction but rather careful and considered planting. Forest gardens can be all about creating shade where it is beneficial while creating sunny, open areas where it is less so and combining plants carefully, in layers, in the most effective ways.