Ask Ruth: Scouting for Microclimates

Dear Ruth,

My fall garden has not done well. The lettuce is under row cover but it already looks awful at the end of November and the real winter has not even started yet. Thoughts?

Michael J.
Asheville, NC

Dear Michael,
Winter is an awesome time to take visual note of various microclimates in your yard. This is especially important if you want to garden during the colder months. Additionally, winter may be the best time to take a critical look at any property you are considering buying. North-side locations are immediately evident, and the prolonged presence of snow indicates especially cold spots. A winter garden will not prosper in cold spots; plus these areas can be difficult to navigate in a vehicle and a house located in a cold spot will cost more to heat. Conversely, locations where the snow melts quickly indicate good potential winter garden spots, a practical siting for driveways and access roads, and a cozier home site.

A couple of years ago I set up my low tunnel running north/south in my garden. The spot is very sunny in the summertime and I often grow tomatoes and peppers in that same location. The plants on one side of the tunnel started looking terrible and cold-damaged. Initially. I decided it must have been my choice of lettuce variety because some varieties are more winter-hardy. Finally (it took a while!) I noticed that a shed was creating perpetual winter shade on that side of the garden, and that half of my tunnel was shady all day long.

In subsequent years, I set up my tunnel on the sunnier side and was much more successful with my cool season garden. This photo illustrates just how VERY cold that shady spot stays. Snow that fell five days ago still remains on the ground in the shady side of my garden, whereas most of the snow in the general landscape melted one day after it snowed.

To clarify…my whole garden spot is very sunny in summer, but part of my garden is very shady in winter. Why? During the summer, the sun is directly overhead. As the year advances toward the winter solstice, the sun gets progressively lower in the sky. We experience this as shorter days. Once we pass the winter solstice – which is the shortest day of the year (on approximately Dec. 21) – our days start getting a little longer each day, and the sun gets progressively higher in the sky until it is directly overhead. This cycle peaks on the longest day of the year during the summer solstice (approximately June 21).

Back to your yard Michael…observe where these especially frigid spots are in your own yard, and site your garden elsewhere. Notice the places animals and humans avoid in wintertime, and notice the spots they gravitate toward in cold weather, and then plan/plant accordingly. Frost flows downhill like water, so watch for areas that capture frost. It is easy to see where frost lays on the ground in early morning. Avoid gardening in those areas if possible.

Gardens require lots of sunshine, ideally at least 8 hours per day. Since deciduous trees drop their leaves in winter, you will need to imagine where the sunny spots will be once the sun is higher in the sky and the leaves grow back on the trees in springtime. Place your garden where it will have full sun – both in summer and winter. If you have not lived in your house during the spring and summer, a compass can be useful for determining where the sun is likely to be during the main growing season and whether deciduous trees will shade your prospective garden spot.

Warmer microclimates also exist in your yard, or they can be intentionally created. A few examples are:

• South-facing masonry walls offer protection from winter winds and the masonry accumulates radiant heat that warms the area. Inside corners are especially protected and make a great location for tender plants like figs.
• An evergreen hedge or a tall fence will create an effective windbreak that moderates the microclimate (plant in a zig-zag for maximum wind-slowing potential). The hedge/fence should not shade your garden site and should be sited to block prevailing winter winds. Caution: Frost pockets can be created above a hedge/fence, so proper placement of the hedge/fence is important.
• Stones and/or pavement will accumulate heat during the winter day (if exposed to sunshine) and radiate that heat during the night thereby moderating temperatures in the immediate area.
• Larger ponds moderate temperatures during every season. They help an area stay warmer in winter and cooler in summer because a body of water changes temperature more slowly than the air temperature. Thoughtful placement of your garden will allow you to take advantage of these characteristics.
• Pollinators enjoy protection from cold and wind, so creating warmer microclimates will enhance habitat for pollinators and entice them to your garden. A rich environment for pollinators will increase your harvest, boost general food security, and aid these valuable creatures.

So Michael, careful observation in your yard – with the assistance of a compass if needed – will help you determine the best location for your cool season garden. Take advantage of winter’s clear indicators – like snow and frost – to decide where to put your new spring garden, where to locate your chicken coop, or to determine the potential of a prospective piece of property.

Regards and best wishes,
Ruth

 

 

Ask Ruth © 2013 Ruth Gonzalez & Organic Growers School