December 2016 Tip of the Month: What Are Microclimates… And How Do You Use Them In Your Garden Or Edible Landscape?
But you might not be familiar with “microclimates.” What are microclimates?
Simply put: microclimates are areas that offer unique growing conditions relative to the broader agricultural zone where they’re located. There can be large microclimates, such as an entire city, a north-facing slope, or a valley that’s much cooler or more moist than the surrounding area.
And there can also be small microclimates, right within your own yard, that offer unique conditions: warmer, colder, more moist, more dry, more sun, more shade.
Knowing the microclimates in your yard can make a huge difference to your success as a gardener. Selecting edible plants that prefer the unique conditions of a specific microclimate will mean better yields and less effort.
Selecting Plants for Your Microclimates
Here are some examples of microclimates and plants you could select for those climates:
- Large rocks, driveways, and sidewalks – Do you have a large boulder, rock, concrete driveway or sidewalk in your yard. These absorb heat from the sun during the day and slowly release that heat at night, making the ground immediately around them warmer (and potentially dryer if there’s not much rain). This means you could potentially extend the growing season of plants placed immediately next to them or put in plants that like more heat and dryer soil.
- South-Facing House Wall – The front, south-facing exterior walls of our house get first sun and stay warm throughout the day. Certain plants that might not normally grow well in our Ag Zone due to it being too cold (example: pineapple guava) do fine when planted near these walls due to the additional heat. We’re also able to extend our growing seasons for our annual plants in these “edible landscaped” beds.
- West-Facing House Wall – The west-facing wall of our house gets early morning shade and then gets blasted with afternoon sun, that’s made even warmer and brighter by the radiative heat and light reflected off of the siding. In the summer, we put in plants that can handle the intense heat and light of the afternoon sun: sunflowers, zinnias, garden huckleberries, corn, horseradish, and others. However, in the fall & winter, the morning sun gets to this spot a little earlier and the extra heat helps keep our garden beds here 5-10 degrees warmer than other spots on a sunny day. We also use low tunnels during the cold months on this side of the house, to bump up the temperatures even further for our cole crops, chickweed, claytonia, carrots, and other cold-weather goodies.
- East-Facing House Wall – Need a spot to put plants that like morning sun and afternoon shade? Put them next to your east-facing wall. For folks living in the south, this might allow you to plant rhubarb or other plants that would not typically be able to take the heat. Fiddlehead ferns and heat-sensitive salad greens that would wilt in the afternoon sun will also grow well here in the spring/summer.
- North-Facing House Wall – The garden areas next to a north-facing wall might only get 4-5 hours of direct sun in the summer and two in the winter. Less sun will usually mean more moisture as well (less evaporation). There are long lists of edible plants that can grow in part-full shade. Our friend Marie Viljoen at the 66 Square Feet Blog has a great list of shade-loving edible plants published on Gardenista. (She gardens year round in New York City in a spot that’s almost full shade in the winter!)
- Low Spots – Need a spot for a plant that likes “wet feet,” e.g. moist soil? Find your low spots. Celery, celeriac, Alexander, parsley, chickweed – all love lots of moisture and grow well during the cool months of spring and fall.
- Slopes – Slopes tend to have poorer soil and lower soil moisture since water and nutrients run off downhill, rather than staying put (unless you have plants to stop the flow or you construct swales or terraces). Slopes can be either hotter or colder, depending on which direction they face relative to the sun. Generally speaking, deep-rooted plants and/or perennials are best for slopes since their roots can run deep to mine nutrition, stabilize the landscape, and avoid toppling over during heavy rains. Chicory, comfrey, fruit & nut trees – all can perform multiple functions on a slope. If you want to see one of the most dramatic and amazing transformations of a heavily degraded, sloped landscape, check out this 13 minute video showing how permaculture design transformed 8.6 million sloped acres in China’s Loess Plateau region.
- Creeks, Boggy Spots, Ponds – It goes without saying that these microclimates are much wetter than other spots might be in your yard/property, and often a bit cooler as well. But that certainly doesn’t mean you can’t grow edible plants in them. True wasabi is a naturally green delicacy and the less expensive “wasabi” you get at most Japanese restaurants is made from dyed horseradish, not actual wasabi. Cattails offer a wide array of delicious edible parts; interesting fact: cattails can produce more edible starch per acre than any other plant! Water lilies and lotuses both produce edible leaves, flowers, seeds, and rhizomes – the rhizomes are considered a gourmet delicacy and often featured in Asian cuisine. There are far too many other edible water plants to list here. Do keep in mind that many waterways are often polluted with contaminants and runoff that you don’t want anywhere near your dinner plate, so plan accordingly.
Next Steps: Identify Your Microclimates
What to do next now that you know about microclimates? As permaculture advocates, we’re big on the principle of Observing and Interacting with the areas you’re going to be growing food in. (Here are the 12 basic permaculture principles that will also help you.)
We’d suggest taking out a sheet of paper to “map” your property. Make sure to put in your cardinal directions (north, south, east, west) then walk your property making notes on your map as to which direction your planting areas are facing towards the sun, whether they’re on a slope, in a low area, etc.. Pretty much every smart phone has a compass on it, to make this process easier. You can also use mobile apps like Sun Seeker or SunSurveyor to see how much direct sun a certain spot will get at a specific time/date of the year.
If you live in an area that gets snow, a great “low tech” way to tell what spots in your yard are warmer and colder is to observe where the snow melts first to last. (Eliza, GrowJourney’s Education Director, has a great article on her blog about this.)
Once you have a good idea of your microclimates, you can create a list of edible plants you’d like to try in each spot at different times of the year.
Experimentation is the goal; trial and error are the expectation. Let us hammer that home: mistakes = learning opportunities, so the more you try, the more you’ll learn. And over time, you’ll learn how to expertly use your microclimates to yield amazing edible results.
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