Any English teacher will tell you there’s no new story plot under the sun, while most gardeners will explain that new plots are everywhere under the sun, just waiting for the right conditions to produce their own green, growing stories. The summer garden is chock-full of drama that often has ramifications long after the growing season is over. Microclimates are one character, or characteristic, of the summer gardening story.
What’s So Important About Microclimates?
Ecosystems are made up of many niche environments. This wonderful diversity results when organisms are drawn to or adapt to small but always significant changes in their surroundings. Microclimates, or unique climatic profiles within a small area, play a role in this. It may look as though the conventional suburban backyard is pretty lacking in exploitable changes in climate and other growing conditions, but that’s not true. Your summer landscape is rich with microclimates. Even better, when you understand them and stop being such a stickler for geometric precision in some of your planting strategies, microclimates can help you become a better gardener. Let’s look at how it works.
Create the Climate You Need
The term “microclimate” may sound like a newfangled marketing ploy, but this approach to cultivation has been around for centuries. One elegant example of creative microclimate modification is the classic three sisters planting model used by the Iroquois Indians as early as the 1300s, according to the Old Farmer’s Almanac. You’ve probably heard of it. On the surface, it’s a companion planting strategy for corn, beans, and squash: The corn provides a support for the beans; the beans contribute nitrogen; and the squash leaves offer cooling and moisture protection to the roots of all three plants during the summer heat.
In the cold, damp northeastern climate, the Iroquois planted the three sisters together on small hills, which warmed the early-season soil and kept it from becoming too wet. This plan fostered plants earlier and encouraged good drainage. The height differences and close proximity among the trio were useful, too. They produced a layering effect that improved light management and created an organic fortification against wind and heavy rain. The three sisters story shows us how small, focused plant and environmental choices, when combined, can produce impressive results.
While you’re in the thick of performing gardening chores this season, start noting how microclimates work in your landscape. Here are some basic factors to keep in mind.
Direction or exposure — You’ve probably already observed a southern exposure has a long growing season and tends to be warmer and sunnier, while a western exposure is typically hot and dry. It’s also obvious to even a casual gardener that northern exposures receive the least amount of sun overall, and eastern exposures usually receive gentle morning light and present fewer problems with afternoon heat. Understanding the benefits and drawbacks of different directional orientations is a key component of good microclimate management.
Light, dappled light, or shade — Directional light exposure is a mainstay of light planning in the garden, but factors like the shade and shadows cast by structures, or the dappled light under a tree canopy, play a role, too. Even the stippling created by tall plants on their smaller neighbors has the potential to be useful, or detrimental, depending on the plants and planting strategies involved.
Heat — Great summer light often comes with the price of high afternoon heat. Heat in the garden can scorch plants directly, warm the surface soil to unhealthy levels, or rob the soil of essential moisture. Reflected heat from walls and dense hardscapes may also create unexpected hot spots. Careful plant selection, increased airflow, calculated mulching, strategic watering, and the use of row covers and other shade producing devices can help. The first step is to recognize what types of heat-related challenges you're dealing with.
Moisture — Today, drought is an issue in many areas throughout the country. It’s always helpful to understand how much moisture your garden is receiving now, and where you should supplement through watering. Is it worth adding an irrigation system and controller, or are your trusty hose and a consistent watering schedule enough?
Uneven terrain — Slopes, and high and low stretches, often result in dry spots, erosion problems, and boggy areas where water pools after a rain. The results of soil deficits, like too much clay or sand, or not enough organic matter, also become more pronounced in pitched or undulating gardens.
Wind — Good airflow is essential for plant health, but wind can be too much of a good thing. Staking plants for added support only solves part of the problem. In the summer heat, persistent wind steals moisture from plants through evaporation. Wind savvy plant selection and calculated wind breaks are very effective, but only if you suss out where they’re most needed first.
Are You a Microclimate Gardener?
Think microclimate gardening is a potential hassle? Not so. Actually, you may already have a robust strategy in place… in your lawn. Lawn seed blends offer a variety of cultivars of a particular grass, or a selection of complementary grasses. They’re designed to thrive in different growing environments, like a shady location under a tree, the dry spot by a mailbox, or the high-traffic area in a tree lawn or along a driveway. These various grasses work together to provide uninterrupted coverage, even in challenging circumstances: where one grass dwindles, another flourishes. This is an example of savvy plant selection based on the anticipated microclimates in a particular landscape.
Read also: Managing Your Landscape with Microclimates
Tools and Tips
Although microclimates have an influence on your garden throughout the year, spring and summer are the prime growing seasons. This makes the microclimate characteristics impacting them a huge factor in the health and productivity of your garden as a whole.
Now that you know a little about how microclimates can work for you, let’s take a look at some useful diagnostic tools.
The 21st century is a great time to be a gardener if you like widgets and thingamabobs that make information gathering easier. The old ways are just as effective, though. Using wind socks and testing the soil’s composition by taking a little nibble will still do the job. If you’re in too much of a hurry to spend an afternoon watching the grass grow, or just love gadgets, here are some suggestions:
Moisture meters — These instant-read probes check soil moisture and often include a pH analysis.
Sun meters — Sun meters are particularly useful in determining whether a northern exposure, or typically shady spot, is getting enough light to sustain plants. Some are instant-read, while others take up to 24 hours to process and summarize their readings. Included in this group are photosynthetically active radiation (PAR) light level meters designed specifically to measure PAR in the 400-700nm color range which is essential for plant photosynthesis.
Sun seeker/identifier apps — A sun identification app will give you a 3D view of the sun’s solar path across your property, together with data-like rise and set times and solar direction for each daylight hour. It can be a good planning tool, especially if you’re installing a new garden or reworking one after a major renovation.
Wind speed gauges — If you think the breeze whistling through your side yard is moving at a pretty fast clip, maybe fast enough to dry out your prized roses, you can find out for sure using a handheld wind gauge that will also give you wind temperature and direction. Wait a few months, and the right unit will provide you with wind chill readings, too.
Weather stations — Where the tools above gather specific but limited information, weather stations are designed to consolidate a number of weather related readings into one device. They’re as close as you’re going to get to a weatherman reporting from your backyard. A weather station is more expensive than a one-trick tool, but it’s also more convenient to use. Here’s why: A basic wired unit will often include information about precipitation, humidity, wind speed and direction, and ambient air temperature. High-end options can do all that plus deliver the information through a wireless network, or Bluetooth connectivity, to an indoor weather monitor. That way, you can view the data from the comfort of your couch, or in some instances, from a remote device like a tablet or smartphone.
If you’ve ever seen a tiny whirlwind of dead leaves spring up in a doorway, or scour a gutter of dirt and grit, you know the vagaries of weather can be small, but surprisingly powerful, and efficient. Understanding how they work in your landscape can help you make the most of your gardening story by developing a plot that’s worthy of your time and effort.