Managing microclimate

Garden climate and temperature

The climate we live in is shaped and influenced primarily by the sun, and to a lesser extent, geography, altitude, location, water and moisture, flora and fauna, greenhouse gases and a variety of other factors. On a significantly lesser scale, each geographic location has its own microclimate - and it’s no different when it comes to your garden. Understanding and managing this microclimate can help you to optimise the growth and health of your garden. While the subject may sound intimidating, it’s actually very simple to understand the microclimates in your garden with just a little common sense.

Effect of Temperature and Light

Temperature is not uniform across any contained or exposed spaces. The temperature reading shown on a thermometer outside your kitchen door is different in other areas of the garden. An open patch of ground will be warmer compared to one under the shade of a tree due to its direct exposure to sunlight. An elevated area, meanwhile, will also be warmer due to the heat retained inside the ground and its fractionally closer position to the sun. It goes without saying that locations hidden or shaded from the sun will record lower temperatures. Why does this matter? Shady areas will be less humid and contain a higher level of moisture. These are conducive growth factors for new saplings and delicate plants. Similarly, more robust plants that require warmer temperature or more exposure to sunlight should be planted outside the shaded zones. If you suddenly discover colder or warmer zones in your garden, that could indicate the presence of frost pockets or water-hungry intruder plants. That might just be the time to put on your deerstalker cap, light a pipe, and commence an investigation.

Dependency on Humidity and Air Circulation

Water vapor in the air helps to trap heat reflected from the ground, which helps to regulate temperature. The presence or absence of water vapours (moisture) in the air is reflected in the humidity level. Rainfall and the presence of bodies of water nearby helps humidity remains at high, which is conducive for heat retention and water supply. Areas with low humidity can still regulate ambient temperature with the assistance of good air circulation. However, air circulation also contributes to drop in temperature. As we all know, heat rises to the top, so strong air circulation will provide kinetic energy to water vapours to float up. You can mitigate the impact with regular watering or by using sprinklers. However, this is only feasible during warm periods. During winter or any other cold periods, you have limited ability in influencing air circulation, especially in the presence of strong winds.

Managing your Garden’s Microclimate

Now that you’ve understand the four primary factors of microclimate deviations, what steps should you take to minimise its negative impacts? Always plant young shoots and saplings in warm zones. You can identify these warm zones by doing periodic ground and ambient temperature measurements throughout the day. Keep the record in a notebook so you can gradually identify hotspots and cold pockets. You can’t deflect or contain wind, so work around it. Use shed or kitchen walls as protection for delicate plant species. Fix loose netting to take the sting out of wind. Orient your crops away from the seasonal path of wind. Perform regular soil testing as well since erosion and cold pockets, amongst other things, can quickly change the soil’s pH level. There are obviously numerous other steps you can take to positively influence your garden’s climate, but these steps should set you on the right path. Once you’ve acclimatised yourself with the basics, explore more complex solutions for your garden.

Tree in sun