Hues of brown and gray now adorn Southwest Florida, to some ‘barren-looking’ and to others a sign that nature’s hand is now evoking the landscape to ‘slow down a bit,’ the growing season is over…A walk around our yard on Saturday revealed what we’ve known for years – upper story cover, trees, can save sensitive plants from a freeze…our heated home also set a protective ‘atmosphere,’ providing a microclimatic effect which abated the recent series of freezing temperature mornings. So what is microclimate? Microclimate can be thought of as walking from a well-light, South-facing room to darker room, North-facing room in your house. You ‘feel’ the effects of heat gain in the brighter room, perhaps air conditioning vents blowing directly on you, and desire to inhabit the room that suites the current Season – aren’t we all just craving the warmth of Sunlight right now??! The home has one roof, but the effects of sunlight, insulation, and moving air also apply to the outdoors.
One of the single-most important aspect to comfort for folks and plants are structures, homes, walls, buildings, and the like offer shelter from the elements. Facing the North/Northwest they can effectively negate cold winds and to the South face can offer comfort on sub-60° days. An effective of several degrees is gleaned on the South face, combined the temperature increase with wind abatement and now moisture protection/anti-desiccation is in your favor (i.e., water demands are lower to counter the effects of cold, dry winds). Sensitive plants meant for warmer climates are protected here during the evenings and reap the benefits of the early morning sun, warming more quickly. The negative to siting plants on this side of a structure can be the ‘oven’ effect during the summer, so choose the plant palette carefully…
Not one single factor can increase the breadth of plants available to your landscape than trees. Microclimate-wise, they can offer: dappled light conditions, moisture conservation, and cold protection via their so-called ‘overstory.’ Trees sited at strategic locations on your lot can also effect your home’s microclimate, reaping energy benefits in the form of tempering heat gain or heat loss, such as in winter. One of the best-documented examples is Thomas Jefferson’s use of this principle on his Estate in Virginia – Monticello
While somewhat more amorphous, exposure has everything to do with knowing the seasonal weather pattern for your area. Plant material selections then derive from optimal placement for rain, warmth/cold, and sunlight. For the purposes of Winter placement, more cold-sensitive material can be placed effectively on the South side of hedges, trees, and structures. You can also ‘cheat,’ with an irrigation system that targets this face to wet down areas to mitigate for cold weather desiccation. In my yard, bromeliads, firebush, porterweed, and railroad vine all reap the benefits of placement via exposure to weather cold weather nights well-East of C.R. 951. Know your USDA Zone (http://www.usna.usda.gov/Hardzone/hzm-se1.html) and observe your landscape for ‘clues’ [and vice versa, microclimates of warm areas] of cold pockets that have been ‘hit,’ avoiding them with sensitive plant placement in successive years. If they are ‘hit,’ avoiding trimming the brown material for as long as feasible (yes, I know it looks terrible) to allow for an additional layer of ‘insultation.’ Think of the brown material above as potentially like the freeze cloth / plastic, the major difference (and benefit) being that you don’t have to remove the cover as the sun rise, thereby not ‘cooking’ the plant material underneath.
So don’t fret if you’re looking for a visual change in your landscape, want to experiment with plant additions, or utilize plants that you have been told ‘don’t grow here.’ Observation, placement, and monitoring are your key to success, without dragging out the cover sheet of plastic or fabric every, single time a freeze is projected. And while you’re at it, enjoy the more wild areas of Florida that now show signs of the cold temperatures – nature’s way of ‘talking’ to plants can apply to us all – just slow down…