Sun and Shade Soil Temperature

September 17, 2024

Maintaining optimum soil temperatures is essential for the healthy growth of plants and crops. Soil is useful in offering structural support for the plants, and supplying nutrients to the plants/crops. There is also the term ‘soil surface temperature’ which refers to the top 4 inches of the soil. This is because the top of the soil is naturally more sensitive to temperature changes compared to soil deeper in the ground. In terms of temperature during the warmer months, soil stores the heat projected onto it, and during the cooler months this heat energy is released from the soil to whatever is growing during this time.

Why is monitoring soil temperature important?

Soil temperature is the driving force for germination, the process by which a plant grows into a seedling. If plants aren’t living in their desired environment, this can have a significant impact on the plant's or crop's overall health and likelihood of achieving successful growth or germination. Soil temperature specifically impacts:

Efficient plant growth: Typically, it is understood that plants grow faster in warmer temperatures, this tends to be related to the amount of sunlight available for them to photosynthesise. A lack of both heat and sunlight correlates to poor growth of plants, of course, there are some exceptions to this rule. At temperatures below 15 degrees, photosynthesis and plant metabolism begin to slow, either reducing or completely halting plant growth.
Soil moisture content: Lower soil temperatures are often related to increased soil moisture levels. It has also been proven that soil’s capacity to absorb solar energy increases with higher soil moisture content levels. Resulting in natural heat absorption and storage capacity, promoting healthy plant growth. Soil nutrient development slows considerably in cooler, more barren, conditions.
Plant Nutrition: Much like moisture content, increased soil temperatures generally promote the breakdown of organic soil matter, great for increased soil fertility, whilst also accelerating soil nutrient availability. Soil temperature affects the soil's consistency - low soil temperature causes the soil to become ‘stickier’ resulting in a lack of nutrient transport. Monitoring soil temperatures helps to prevent undesirable soil consistency and maintain optimum plant nutrition levels.

Sun and shade planting:

Sunlight exposure is essential when it comes to plant and crop growth. Sunlight produces the energy that plants need to grow, however, every plant is different and some require more sunlight than others.

Plants and crops that thrive in direct sunlight include:

Aloe Vera
Lavender
Geranium
Hibiscus
Basil
Sunflower
Marigold
Tomatoes
Peppers
Cucumbers
Strawberries
Pumpkins

Plants and vegetables that thrive in the shade include:

Snowdrops
Foxglove
Various evergreen plants including Ivy and Fern
Brassicas, including broccoli, Brussels sprouts, and spring greens)
Beetroots
Radish
Leeks (light shade)
Kale (light shade)
Broad Beans (dappled shade)

There's more to sunny and shaded areas than just that… There are a variety of areas that experience different forms of sunlight and shade, these include:

Sun: An area that on average, receives at least 6 hours of sunlight per day.
Partial sun or shade: An area that receives on average 3 to 6 hours of sunlight per day.
Dappled shade: An area under deciduous trees receiving pockets of sunlight creating shifting patches of sun and shade in one location.
Shade: An area that consistently receives little to no direct sunlight.

Soil Thermometers:

Soil Thermometers are the most common and accurate method of measuring soil temperature. At ClimeMET we supply a selected range of soil thermometers, ideal for various soil depths. We stock short and long-length thermometers, complete with your choice of either a brass or aluminium casing.

The ClimeMET Sun and Shade Soil Thermometer Bundle

DID YOU KNOW? Purchasing our Soil Thermometers as a pair will allow you to simultaneously measure, and compare, sun and shade soil temperature readings.

Useful in microclimates such as gardens and allotments that naturally receive varied sunlight exposure. Use one thermometer for shaded soil temperature measurements, and the second thermometer for direct sunlight soil temperature measurements. Ensure when taking these measurements, that they are recorded at the same time of the day for the most accurate results. Monitoring soil temperatures in both sun and shaded areas provides you with the knowledge to make informed decisions on optimal planting and growth opportunities, and know when and what is best to plant in specific areas at certain times of the year. Typically, the optimum soil temperatures for healthy soil growth and moisture content sit within the low 20-degree range.

FAQs:

Can some plants grow in both sun and shade?
Yes, some plants can adapt to both sun and shade, though their growth and flowering rate may differ depending on the light exposure.

What are some easy-to-grow sun plants for beginners?
Beginner-friendly plants include marigolds, sunflowers, tomatoes, and basil. These plants are relatively easy to care for and thrive in full sunlight.

How do I know if my garden spot is suitable for sun or shade plants?
Take note of how much sunlight the spot receives throughout the day. Full sun areas receive at least 6 hours of direct sunlight, partial shade areas receive 3-6 hours, and full shade areas receive less than 3 hours of direct sunlight.

Are there any tricks to maximize sunlight for sun plants in a partly shaded garden?
You can maximize sunlight exposure by positioning reflective surfaces, like white fences to bounce more light onto your plants. Trimming back overhanging branches can also help increase sunlight exposure.

Do shade plants need special soil?
Shade plants prefer well-draining, rich soil with plenty of organic matter. Adding compost can help improve soil quality and drainage.