Making microclimates

Microclimates are small areas on your property that are warmer, cooler, wetter, drier or more sheltered than the broader climate for your region. In our garden, we use the areas that are sunny and naturally more protected from prevailing winds for growing vegies, and the shadier places that get smashed by the wind for drought-hardy natives.

You can also create microclimates to improve your growing situation. Here are a few you can explore for your place – no matter your climate.

Cold frames and greenhouses

Gardeners in cooler climates will benefit from some type of warmer microclimate, such as a cold frame or greenhouse.

A cold frame can either be fixed or a portable structure that can be moved along a vegetable garden, as needed. You can also build a very small, temporary cold frame by resting an old window on top of a rectangle of bricks, with space in the middle for seedlings.

Greenhouses are permanent structures that you can walk into. It’s not possible for everyone to have space for a greenhouse, but if you do, they can be a life-changing addition to your cool-climate garden.

Shade and windbreaks

All climates benefit from shade. Here in lutruwita/Tasmania, our summer sun scorches the earth, but in winter you need all the sun you can get. So deciduous trees and vines that drop their leaves in winter and let the sun stream through are your best friend.

In hotter climates, you’ll be wanting some permanent evergreen shade trees to soften the sun and hot winds year-round. Aim to shade your garden from the western (afternoon) sun, which is particularly strong. You can do this with shadehouses (walk-in structures covered with shadecloth), trees, shrubs, or vines scrambling across fences or pergolas.

You can also use smaller structures called cloches for annual crops. Ours is made from 25mm blue line poly pipe covered with shadecloth or clear plastic, or you could make a larger version from sheets of reo mesh bent over the beds and then covered with shadecloth.

Excess rainfall

We are always working to improve our soils with quality, organic compost and good garden practices, but we recently experienced three wet years in a row, resulting in compacted clay soils and waterlogging with some of our edible crops. Here are solutions that worked for our annual vegetable garden.

• Cover resting garden beds with silage tarp (UV stabilised, non-toxic plastic during a wet season to control how much rain hits the soil.
• Use mini cloches, with a clear plastic cover to keep the rain off the soil, and open ends for good ventilation. This has worked wonders in getting our crops established and protecting our soils. Larger walk-in hoop houses can be a more permanent solution to this, while creating a warmer microclimate for those who need it.

Water

Small or large ponds can help regulate the temperature in the garden, as water can, in fact, heat and cool your garden.

• Water is a thermal mass. Throughout the day, the water drinks in the sun and slowly releases the warmth overnight, benefiting nearby plants. This function can sometimes moderate minor frosts.
• Throughout summer, water bodies release moisture into the area directly around them, creating a more humid environment for plants to enjoy. When a pond is positioned upwind, prevailing summer winds blow across the water, cooling them down as they move. Your pond acts as a kind of air conditioner.

Use materials to create microclimates

The materials you use in your garden can help enhance a certain microclimate.

Cold climates Bricks, stone and grave are a few materials that are commonly used in gardens to catch and hold onto heat from the sun, then slowly release it into the night. The darker the colour of the material, the more heat it will absorb.

Warm climates Reflective surfaces, including corrugated iron and a range of surfaces painted white, are perfect for people gardening in warmer regions, to reflect the heat away from the plants.

Whether you’re in an arid or alpine region, the tropics or subtropics, or any temperate climate in between, we all have climate limitations that affect our gardening. But as any keen gardener will tell you, there are ways to bend reality (just a little bit) to get the most out of our gardens. And with climate change swirling around us, there’s an increasing need to learn on our feet to craft microclimates that ensure nothing stops us growing.

Images by Natalie Mendham