Sonia Uyterhoeven is Gardener for Public Education. Join her each weekend through November 15 for home gardening demonstrations on a variety of topics in the Home Gardening Center.

With all of the crazy weather we’ve had this year, there has been a great deal of discussion of how weather and climate affects the plants we grow and cherish. This reminds me of the importance of microclimates in the garden and how it allows us to often successfully push the vegetative envelope.

Recently a woman came to a Home Gardening Demonstration that I was giving on herbs and herbal vinegars. We were looking at a collection of healthy rosemary I was growing in containers, a beautiful, blue upright cultivar called ‘Tuscan Blue’. We then wandered over to another section of the garden where a less robust specimen was struggling in a mixed border.

Rosemary, I explained, is borderline hardy in the New York area. We generally keep it in the ground over winter (it is a perennial herb) and then come back and check on it in the spring to see how it has fared. Usually, it is in such a sorry state that we end up removing it and replanting it with a specimen that has been protected in our greenhouses.

“Oh!” she exclaimed, “I had rosemary that flourished at my home for 5 or 6 years, and it never required any winter protection.” She then proceeded to explain that her rosemary had been situated in an area of her garden that was bordered by a cement walkway, which absorbed heat and warmed the bed. A few feet away, the white walls of the neighbor’s house reflected a fair amount of light into the border.

She had found a perfect microclimate for successfully overwintering her rosemary and other Mediterranean plants. The area provided shelter from damaging winter winds, good drainage, and just enough additional warmth to escort her rosemary through the chilly winter months.

This story reminded me of a friend’s New Jersey garden. The brick house’s laundry room heat vent opened up onto a section of the garden where he planted cannas (pictured), and he never had to lift them in the autumn. They flourished in their niche. read more »