What are Microclimates?
Knowing the importance of microclimates is essential for a garden that thrives at a high altitude. What are they? A microclimate is a small, but distinctly different climate within a larger area. These small areas may be a little warmer, cooler, wetter, or drier depending entirely on their location. Becoming aware of these small climate pockets helps mountain gardeners to choose and site plants more wisely.
Looking for warmer microclimates
Gardens on south-facing slopes are warmer and drier than gardens on north-facing slopes of the same valley at the same elevation! So a garden planted in full sun on a southern-exposed slope will have a longer, warmer growing season than other exposures. Southern exposures are a great place for plants that need more heat to come into flower before early autumn frosts.
Things like structures, fences, large rocks, walls, and trees can all act to provide protective screening from harsh winds. Their thermal mass can raise nearby temperatures and create a warmer microclimate in those areas.
Becoming aware of cooler microclimates
Plant growth is slowed by cool soil temperatures, which drive plant metabolism. When soil temps drop below 55 degrees, plants stop growing. North-facing areas and low spots on your property will naturally be cooler.
Look for any small dips and indentations on your property, which can create collections points for cold air. As a result, frost pockets may be more likely to form in those spots.
Walk through your property carefully looking for these microclimates. This will help you place your plants and shrubs where they will have a better chance at succeeding, and your mountain garden will thrive!
Sources: https://extension.colostate.edu/topic-areas/yard-garden/colorado-mountain-gardening-basics-7-224/