Have you ever noticed in your garden how some plants of the same species (even the same variety) will often grow quite differently in your garden? Perhaps you’ve observed a single plant grow huge, while the rest of the plants around it randomly shrivel and die. Maybe you’ve noticed that plants tend to do better squished up against the edges of your raised beds while the middle of the bed quite often has the lightest growth. Experiences like this can be confusing and frustrating, especially for beginning gardeners experimenting with plants they aren’t familiar with.
What we need to remember when we grow is the dynamism of our garden environments, which are a lot different than the picture presented traditionally of long rows of perfectly trimmed vegetables. The best way to think of our patios and backyards is as a complex ecological system than can vary quite dramatically in areas separated by only a few feet. Energy flows through the system as the result of wind, sun, water, and life. Permaculture helps us to understand the identifiable patterns of energy that flow through natural systems.
Credit: Bill Mollison
Once you observe and recognize the patterns of energy that are flowing through your garden, you’ll be able to identify and label areas of your garden, known as micro-climates, by their environmental characteristics. This in turn will give you a huge advantage in choosing the right type of plants to fill each of these niches.
What is a microclimate?
A microclimate is a small area that has the same environmental conditions in terms of wind, sun, temperature, water, and soil. It can be as simple as the area next to your house being warmer than the rest of your garden because of the heat absorbed by the wall or the shade produced by a nearby tree during part of the day. It can get as complicated as considering all the tree roots and fungal hyphal networks and how they move nutrients through the soil.
Creating your own microclimates
Here are some tips on recognizing factors that might contribute to the creation of a microclimate.
The sun moves from east to west, with azimuth (height in the sky) differing seasonally. Look for areas of your garden that might get blocked by other garden features and receive shade for 4 or more hours per day.
You can actually see how trees adjust to prevailing winds because they will lean away from the direction the wind is coming. Looking at how much your local trees lean can give an indication into the strength of the prevailing winds. If you have a strong prevailing wind, look for areas in your garden that are sheltered from the wind.
Water obeys the law of gravity; following the path that water moves from the highest point to the lowest point in your garden can help identify areas where it infiltrates (soaks) into the ground more slowly.
Observing the type of weeds present in areas of your garden can help to indicate the soil types (heavy, loose, compacted, nutrient-rich). Nearby trees can also influence soil by changing the chemical composition (eg., conifers making soil more acidic), alleopathic tendencies (eg., black walnut), or simply spreading lateral roots that compete for nutrients.
Rocks, stone and earth banks are great thermal stores, saving up their energy during the day and releasing it at night. Identifying these features in your garden can indicate areas where plants requiring a warmer climate than your current one could flourish.
Creating your own microclimates?
It can sometimes be hard to identify the microclimates in your garden, especially if your time to experiment/observe is limited. Here are a few classic ways to create your own microclimates.
Hugelkutur is a method of creating a microclimate with increased warmth, moisture, and increasing alkalinity, it involves taking waste timber scraps from your yard (branches, logs, compost, etc.) and mounding it into a trench and covering with soil. The logs will gradually decay from fungus digesting them over many years and turn into the perfect soil for growing herbaceous plants and fruit trees. The logs soak up moisture like a sponge and release it slowly and the decay of the logs will keep the ground warmer than the surrounding soil.
Sepp Holzer, an Austrian farmer growing on mountain ridges in the Alps, refined this German technique and applied it very successfully on the steep slopes of his farm to create pockets of warmth to successfully grow a diverse set of berries and fruit trees.
Follow this link to read a blog post about how a fellow permaculturist near us in northern Virginia set up a hugel bed.
It may be hard to create a large enough pond in some of our yards to create microclimates, but these water features naturally produce 4 microclimates on each of the banks of the pond. Energy flows more rapidly along the edges of where two medium meet, so the banks of ponds are extremely productive because of the natural edges it creates.
Sun-facing slopes are warmer and drier; Pole-facing slopes stay cool and moist, but capture reflected winter sunlight useful for late fruiting plants. East slopes dry out in the morning, which is good for suppressing fungal and viral diseases. West-facing banks of the ponds are hot and dry during the summer.
Shawn Jadrnicek has done a lot of research on pond microclimates and integrating ponds with greenhouses, detailed in his book, The Bio-Integrated Farm. You can get more details in his book on what to grow in pond microclimates.
How to use microclimates for more yield
To illustrate microclimates in an urban setting, I’ve included a photo of our front yard, marked up with the different microclimates I’ve identified so far in the yard.
- Sheltered area gets sun all day, is protected from the wind by the stairs, and gets good water runoff.
- warmer because of the front wall of the house on it’s north side, but doesn’t get full day sun because of the neighbor’s cherry tree.
- this area gets full day sun, but is fully exposed to wind from the west and browsed by passers-by.
- Deep soil area naturally accumulating runoff from our front rain gutter. Only gets partial day sun though because of the neighbor’s cherry tree.
- Shadiest part of the front lawn. Also competes with the root system of the neighbor’s cherry tree.
- Gets some nice root shade and thermal effects from the herb spiral tucked in behind it. Gets almost full day sun.
- almost full day sun, and some wind shelter from the plants in zones 6 and 3. Gets some runoff from the microswale between zones 7 and 2, although most of that runoff goes to zone 4.
As you can see, even in this small 15′ x 15′ area, there are a large number of different microclimates. Identifying microclimates is a fundamental part of successful permaculture design, since finding the best comfort zone for our plants and stacking functions can produce abundant harvests.
Even after years of vegetable gardening in my front and backyards, I still have trouble seeing the minute details and patterns in my garden. Although I’ve presented a few tips and tricks to help guide you, I still feel the best way to find the microclimates in your garden is to experiment.
One strategy you can use is taking seeds of all the varieties you might be interested in growing in your garden and broadcast spreading them in your planting areas, to see what germinates as well as what thrives. Although this may seem like a wasteful usage of seed, you’ll get a much faster understanding of what your microclimates are.
So now that you know a bit about microclimates, what do you think you can grow in your area? Or if you already used microclimates to your advantage, share what worked for you in the comment section below.