The term microclimate describes the climate of a small, specific place within a larger area. This could be a hillside on the edge of a city or an area as small as a backyard or park which can then have several different microclimates of their own depending on how much sunlight, shade, or exposure to the wind the space gets.
For example we live in Hobart, a cool temperate region – think frosty, cold winters with snow on the mountain and mild summers. However we live on N.E facing hillside on the edge of Hobart city where we’re protected from the full force of the wild westerly winds and the chilly southerlies. We only get mild frosts over winter and once we chop down some particularly massive cypress macrocarpa trees on our NW side, we’ll have all day sun hitting both the house and garden. Our property is also above the cool air drainage and harsh frosts that hits the valley floor (full of houses) below us. In summary, it’s a good spot.
Within our property exist several microclimates. We have an area we affectionately call ‘Greece’ as it’s the driest, rockiest place with good warmth while another corner has been named the ‘Tropics’ as it gets the best sun ever and, being lower than Greece, we can channel water to it creating a moist and warm climate.
No matter where you are you can create microclimates to enhance your food production and create super productive landscapes. As we live in a cool climate region we’re completely focused on making WARM microclimates.
Example A is the gabion wall which we’ve planted a Satsuma Mandarin in front of. This is actually our neighbour’s wall but we helped build it and it sits on our boundary line, so we get to utilise it (yessss). We’re pretty happy to have a N.E facing rock wall acting as a massive slab of thermal mass, catching and storing the sun’s heat and making it available to the mandy.
One of our other favourite microclimates on our property is actually inside the house (yes, microclimates exist inside buildings too). Our front sun room is 50% glass and we treat it like a hothouse, raising all our seedlings in their each winter for Spring plantings. We do intend to actually build a glasshouse in the garden, but haven’t quite got there yet.
Propagating with a view
And then there’s David Holmgren and Sue Dennet’s home in Hepburn Springs, Victoria. Having designed and built their own mud brick house they’ve integrated a glass house into their home. Not only does it provide a kitchen garden pretty much in the kitchen, it also produces valuable heat which travels throughout the house, creating a toasty environment.
Integration of home, garden and heater – beauty in action!
Another technique for the garden is something called hugelkultur, a method for growing food, composting large amounts of organic matter and creating a warmer microclimate all in one – in terms of being multifunctional, it’s pretty up there. Basically, it’s a raised garden bed full of rotting logs, timber offcuts and rich nitrogen materials (manure, food scraps, fine green waste etc) which generate some heat as they slowly compost. Eventually (after years) you’re left with beautiful brown soil. One thing to keep in mind is the type of wood you use, generally avoid (if you can) trees like cypress macrocarpa which are anti fungal and want break down for a looooong time, which is why this timber’s so good as fence posts. Timber that is ideal includes alders, apple, poplar willow (dry) and birch.
A local market gardener south of Hobart in Cygnet (Kylie Maudsley) is using hugelkulture to take care of the large amount of scrub she’s cut back, including making hugelkulture ‘donuts’ around her young bunya pine. This little microclimate is protecting the youngster from wind, generating extra warmth and providing valuable nutirents, so good!
Kylie is also growing macadamias, she’s from Queensland and misses the plants from up that way. As you can see below she’s covered the macca with a white frost protection coat, then surrounded the lower half with a thick padding of manure with a final layer of straw bales to both generate heat and insulate the whole shbang.
A macadamia tree well and truly tucked in
And then there’s water. Did you know that water bodies of any shape and size (from buckets to dams) are effective ways of creating heat sinks throughout your property? On an evening where you’re expecting frost the next morning, you can literally place buckets of water next to frost sensitive plants to help protect them.
Water is a powerful tool to moderate climate, being a heat sink it operates as thermal mass – retaining heat and releasing it when temperature changes occur. This can create a small frost-free area for a longer period around it, thus giving a bit of a season extension.
Permaculture property, Whole Systems Design, are based in Vermont and are experimenting growing rice in a series of ponds. Yes, that’s right, in Vermont.
On his farm in Austria, Sepp Holzer has designed water into his landscape on a large scale, helping to creating warmer microclimates for the crops he grows around them.
Furthermore, light is reflected off of the water surface. You can use this to your advantage by growing strategic plants directly around the water body which crave the extra heat. Appropriately placed ponds near houses can also give extra solar radiation for warming the house due to the reflection.
A couple more options for creating warmer microclimates include:
- Pathways – by having white gravel paths you can reflect light back onto surrounding vegetation. Black paths function as a heat sink and slowly release that heat to the garden directly next to it.
- A brick/rock wall facing the sun provides the perfect microclimate to grow heat loving fruit trees and crops against it.
- Small to large glass/hot houses, perfect for propagating and/or growing crops in the ground
The great news is that there is almost ALWAYS a way to grow the crops you’d like to grow where you live. Although I’m not about to try and grow mangoes in Hobart but I will be giving avocados a good go!
*Your blogger is Hannah Moloney, co-director of Good Life Permaculture and lover of all things fun and garden-esk.