Climate refers to weather conditions in a particular area over a long period of time. We often refer to climates as hot, cold, dry, humid, sunny, or windy. Microclimates can have the same descriptors. They just exist on a smaller scale.
Recognizing and understanding the microclimates in your garden can provide you an advantage over your fellow gardeners. Every plant will grow best in a location that has the ideal soil, light, and water that that plant requires. When you can place plants in the best locations that your garden offers, you give them the best chance for success.
To identify microclimates look for variations in the growth of your plants. If you have a long hedge or line of plants, how do they differ? Do the plants at one end grow better than the ones at the other? You may be observing a microclimate.
Many gardeners fight microclimates. They try to force plants to grow in spots that aren't ideal. They assist under-performing plants with extra water, fertilizer, and attention. The reason for the stunting may be due to the climate that exists in that specific, limited location. The plant may be struggling against heat, light, wind, or humidity differences that don't exist just a few feet away.
When you acknowledge that your garden has distinct growth patterns in separate sites, you can take advantage of it. That may mean moving plants. Transplanting from a stress area to a supportive one can make a plant prosper. Choosing to sow and grow appropriate plants for each respective microclimate gives them improved opportunities.
Looking for microclimates in summer may identify errors in planning and planting. When you place your flower bulbs in spring or fall, that garden plot may be in full sun. In the midst of summer that location may now be in shade. Maybe that explains why the flowers don't seem to bloom as they should.
The opposite can hold true. I planted Hostas and Bleeding Hearts one spring in a nice, shady, sheltered garden bed. They didn't do very well. The next summer as the stunted, struggling plants finally succumbed to stress I realized that the seemingly ideal spot in spring was inundated by heat and light in the summer, a situation that wasn't ideal for those plants. I replanted the entire bed with more appropriate sun-loving flowers like Daylilies.
You don't need to overreact when you identify microclimates. The plants may not be at their prime, but if they're doing okay leave them be. When it comes time to modify your beds, take the microclimates into account and then you can change the plants, if you choose.
Look for microclimates in your garden. Some areas like abundant shade or sun are easy to identify. Subtle zones may take more and longer observation. The differences may not be enough to warrant change, but awareness can help you relax a little and help explain why different plants grow differently. Being able to identify the different microclimates in your landscape may not change any of your gardening choices, but knowing about them will make you a more knowledgeable gardener.