In gardener’s jargon, deciding where to put a plant is called “siting” it—deciding on a site for it. Proper siting of a plant involves selecting a plant that is adapted to your region, then selecting the best place in your garden for it. The elements often put sharp restrictions on plants. Each plant has a cold and heat range beyond which it won’t flourish.
Decisions made in selecting and siting plants have a significant impact on the time spent in caring for them. Plants that are adapted to the weather in your region and sited in microclimates that suit them will thrive with little care on your part.
Weather and Plant Selection
A wise gardener takes the time to choose plants appropriate for the weather conditions of her region. Inappropriate plants can be a problem, especially among our mobile populace (as when a Chicagoan retiring to Phoenix attempts to recreate a lush Midwestern lawn in the desert). Select plants that are native to your area or to a part of the world that has a climate similar to yours.
Microclimates and Plant Siting
Learn to read the microclimates of your garden to find just the right spot for each new plant. All gardens are composed of dozens of different microclimates. Good gardeners understand the microclimates of every spot in their garden. Some spots are warmer, some cooler. Some get full sun in the morning when it’s cool, and some in the afternoon when it’s hot.
When a plant isn’t doing as well as you had expected, it could be located in a microclimate that’s not ideal for it. Try moving it to a warmer or cooler or wetter place. You might even move a plant several times to find just the right location.
“Nativity” refers to the part of the world and type of climate to which a plant is adapted. When selecting plants, and when selecting places to plant them in your garden, try to find out what conditions they experienced in the wild. They “expect” those conditions, and their strengths and weakness stem from those expectations.
For example, most rhododendrons and azaleas are native to the mountains of Southeast Asia, where it rains almost every day and the vegetation is lush. The soil is acid from the frequent rainfall and rich in organic matter. Rhododendrons and azaleas are adapted to acid soil, and can tolerate more acidity than most plants. But acid soil is rich in iron, which is made more available by acidity, so they can’t tolerate a shortness of iron, and show iron deficiency symptoms in soil that is too alkaline. They “expect” soil that is always moist, but which drains quickly to admit air readily.
You can imitate the conditions they prefer by planting them in a shady location in soil that has been enriched with 50% peat moss. The peat moss holds water like a sponge and is very acid. In the forest, their roots would be mulched with a constant falling of leaves and litter, keeping the shallow roots moist and cool. Give them an organic mulch about 3 inches deep.
The more you can find out about the conditions a plant evolved in, the better job you can do of selecting plants that are suited to your climate and giving them the microclimate they need.