GARDENING : Don’t Like the Microclimate? Move a Few Inches
If you’ve ever brought home a plant that’s supposed to grow in your area and carefully planted it in your yard, only to see it fail, it could be that you chose to plant in the wrong microclimate.
While home gardeners are aware of Orange County’s general climate, and many even know the conditions in their particular city, they often don’t realize that every yard has its own microclimates, which are hot and cold spots in the yard.
Because houses vary in size and shape and location in relation to the sun, and many lots have trees, every yard has a variety of unique conditions, says Vern Hee, co-owner of Leaves of Grass Landscaping in Lake Forest.
In any yard a wide variety of microclimates is possible, such as cold low spots on the north side of a house, which don’t get light and have a tendency to freeze in the winter, to areas next to white, south-facing walls that get sun all day and stay four to five degrees warmer than surrounding areas.
“You can have countless microclimates in your yard,” Hee says. “For instance, you could plant a row of gardenias along an 87-foot wall. The plants may thrive in some areas (along the wall) and die in others, all because of microclimates.”
Many home gardeners discover they have microclimates when certain plants are zapped by a freeze, says Scott Lathrop, general manager of Flowerdale Nurseries, Inc. in Santa Ana.
“After a freeze, many people will notice that only plants in certain areas were affected,” he says. “Plants that freeze are usually on the cold north side of a house, out in the open and unprotected by walls and trees.”
To have success in such a cold spot, Lathrop suggests planting cold-loving plants such as lilacs, certain fruit trees and azaleas and camellias, which will have better, longer-lasting flowers because of the cooler temperatures.
On the other end of the spectrum are frost-sensitive plants that should never be exposed to freezing temperatures. “Put delicate plants such as impatiens in areas that are protected by a house overhang or trees,” Lathrop says. It is especially helpful to place such plants near a south-facing wall, which will radiate warmth to the plants during the night.
Other common microclimates found in many yards are hot spots, which cause grass to brown in certain areas. “Hot spots are sometimes created by the sun reflecting off of a home’s windows,” Hee says. “This can increase the temperature in certain areas of the yard by several degrees, which makes it necessary that the area receive more water than surrounding grass.”
Another microclimate that calls for increased water occurs when an area of grass is near large trees that suck up water. “In Lake Forest there are many eucalyptus around the lake, which are taking water meant for the lawns,” Hee says. “This makes it difficult to keep the grass alive, unless you are continually watering it.”
Many homeowners also struggle with the microclimate that occurs next to western exposure walls that receive constant sun. “While the surrounding temperatures can be 80 degrees in the summer, this particular microclimate can be 20 to 30 degrees higher,” Hee sayd. Needless to say it is difficult to keep many plants alive in such conditions. You must either plant drought-tolerant, heat-loving plants such as cactus in the area, or modify the surroundings by planting a tree that will give some shade.
Hills in the landscape also create a variety of microclimate situations.
Debby Rettino has a hill at the back of her property in Coto de Caza. “This half-acre hill is in full sun all day long,” she says. “While part of the hill is filled with fruit trees that do quite well, it has been difficult finding other plants to put in the area that don’t bake in the sun or require enormous amounts of water to stay alive,” she says.
In the front of her house Rettino also has a small area that receives full sun all day long. There she grows geraniums and boxwood hedges. But move over just a few feet and you’ll find another microclimate that consists most of the day of shade created by the house. In this almost full-shade area she has had success with impatiens, gardenias, a variety of bulbs and a jacaranda and three sycamore trees.
On the right of her house, Rettino has an English cottage-style garden that is in the shade for more than half the day, which means she must be careful not to put in flowers that require a lot of sun.
Another microclimate in Rettino’s yard that she is very happy with is a rose garden on the side of the house that sits next to an oak grove. “This area receives full sun in the morning and then when the sun rises to the oaks, the area gets filtered sunlight for about half the day. This causes the roses to reach up for sun and develop extremely long stems,” she says.
When choosing a microclimate for your rose garden, Hee suggests picking an area that receives a lot of heat. Placing plants against a western wall is a good choice, especially if you live in a coastal area, where damp conditions make roses more susceptible to rust and black spot, he says.
It’s also possible to use microclimates to grow delicate plants such as the tropical bird of paradise, which will thrive in Orange County if given the right conditions, Hee says. “Atriums and courtyards make good tropical microclimates that can be 80 degrees while the weather is 60 or 70 degrees.”
Pat and Dick Evleth, who live in a tri-plex in Laguna Hill’s Leisure World, have a courtyard filled with tropical plants, including tupidanthus and mandevilla, that need sheltered conditions. They are able to grow these exotic plants because of the special circumstances within the courtyard.
“The courtyard is 10 feet wide by 22 feet long and has white walls, which keep the heat in,” says Pat Evleth. “During the day, the sun is constantly moving over the area, which means that the plants aren’t hit by harsh, direct sun. The walls also keep the area protected from cold or hot winds.”
Microclimates can also enable you to grow certain plants, such as tomatoes, out of season. Plant an indeterminate-type tomato along a south-facing white wall in the fall, and the area will probably generate enough heat to enable you to have fresh tomatoes for the holidays.
