Creating microclimates in the garden
This article was originally published on July 24, 2013 and expired on August 24, 2013. It is provided here for archival purposes and may contain dated information.
URBANA – It is always recommended
to purchase perennials, trees, and shrubs based on your USDA hardiness zone,
said University of Illinois horticulture educator Candice Miller.
"But the fact is you can create microclimates in your garden
that allow for growth of plants outside the hardiness zone," she added. "By creating a microclimate, a gardener in northern
Illinois for example, which is mostly zone 5, can potentially grow a zone 6 or
7 perennial or shrub in an area where he normally wouldn't be able to."
For more detailed information on microclimates, Miller cited
the Cornell University Extension website at http://www.gardening.cornell.edu/weather/microcli.html.
According to that site, a microclimate is the climate of a small area that is
different from the area around it. This area may be warmer or colder, wetter or
drier, or more or less prone to frosts.
Microclimates may be rather small, a protected courtyard or
raised bed, for example. Or a microclimate may be large, like a band extending
several miles inland from a large body of water that moderates temperatures,
such as near the Great Lakes.
Your home and the other buildings around your yard can
create many small microclimates. Your house absorbs heat during the day and
radiates it back at night. If winds are from the northwest, this creates a
warmer, more sheltered microclimate on the south and east sides of your house.
"This would be the best area to plant those out-of-zone
plants," Miller said.
Paved areas like patios, driveways, and sidewalks can also
absorb heat during the day and re-radiate it at night, moderating night-time
soil temperatures and helping to protect from frost.
"You can enjoy earlier blooms by placing plants next to
paving or structures that radiate heat as well," Miller recommended. "A heavy
clay soil also acts similar to pavement, trapping heat and moderating
Barriers created with fences, walls, large rocks, or
structures can also protect plants from wind and radiate heat, creating
"Of course, there are always the benefits of adding mulch to
the landscape," Miller said. "Two to three inches of mulch can cool the soil
during the summer and help retain moisture, but even more important, several
inches of mulch will protect plants from the cold during the winter by
moderating the soil temperature."
"Whatever your choice of method for creating microclimates
in your yard, fashioning areas in your landscape to be able to grow some of
those more unique plants can be a fun adventure," Miller said.
Source: Candice Miller, Extension Educator, Horticulture, firstname.lastname@example.org
Pull date: August 24, 2013