How to Measure Soil Moisture in your Garden

Soil moisture is an important measurement for any gardener to know. When soil is overly dry, plants can struggle to uptake nutrients and water, leading to yellowing leaves, wilting, and even plant death if the drought continues for too long. In contrast, when soil is overly wet it can lead to fungal diseases that thrive in saturated soils. The balance between wet and dry is optimal for plant growth, but how do you measure the moisture of your garden beds? If your garden has different levels of soil or types of soil that have different moisture retention capabilities, it’s important to find out sooner rather than later. This will help you understand which areas need more watering and which should see less irrigation. Measurement of soil moisture is also key if you want to use raised beds or planting boxes with different pre-installed soils that have their own unique properties.

Soil Watering 101

One of the most important things to remember when it comes to soil and plant care is that different plants have different watering requirements. Some plants require soil that is barely moist while others, like vegetables, need soil that is kept consistently moist. Plants with fibrous root systems, like perennials and shrubs, need consistently moist soil while plants with taproots, like tomatoes, need drier soil during their growth and then moisture in their roots when they begin to grow foliage. While plants will usually inform you as to what their needs are, it’s always a good idea to keep an eye on things. If you notice wilting or yellowing leaves, this likely indicates a lack of water in the soil. You can also poke your finger down into the soil, about 4-6 inches deep. If the soil feels dry, it’s time to give it some water. If it feels damp or even wet, it’s best to avoid watering at this time.

Measuring Tools

When you want to measure the moisture of your soil, you will need a tool to do so. There are a few ways to accomplish this, each with their own advantages and disadvantages. Paper – You can use a paper towel to measure soil moisture. Just dig a small hole in the ground, place the paper towel in the hole, and close the hole back up. Come back to the paper towel in about 24 hours and you will be able to read the moisture level on the paper towel by the colour it turns.

String – String can be used to measure soil moisture. Just tie the end of the string to a wooden stake, bury the string right down to the bottom of the soil, and then come back after 24 hours to see how wet the string is.

Probes – Using probes to measure soil moisture is more of a long-term measurement, but it does give you a very accurate reading of the soil’s moisture level. This is ideal for gardeners who have plants in beds year-round.

Using Your Fingers to Measure Soil Moisture

This is an old gardener trick that can be a quick, easy, and effective way to measure soil moisture. Simply dig a finger into the soil about 6 inches deep, and then remove your finger. If the soil is moist, your finger will be wet. If the soil is dry, your finger will be barely moist. You can find these measurements on a moisture scale below:

Wet – Your finger will be dripping with water. This soil is too wet for growing plants.

Soggy – Your finger will be moist but not dripping wet. This soil is good for growing plants.

Slightly Moist – You can barely feel any moisture on your finger. This soil is good for growing plants, but keep an eye on it.

Slightly Dry – Your finger will be dry but still moist. This soil might need watering soon.

Dry – Your finger will feel dry to the touch. This soil needs more moisture.

Electronic Soil Moisture Meters

Also referred to as probes, these tools are like a more high-tech version of the paper towel method. The probes are either placed in the ground or left outside in pots of plants. They then send a reading to a handheld device that shows the soil moisture level.

Pros – You can place many probes in the ground and read the moisture levels of multiple gardens or pots at the same time. This is ideal for large gardens with many plants and pots.

Cons – The probes are only effective for long-term measurements. You will have to reset them often or purchase a device that resets itself.

Tips – You should place the probes in areas of your soil that receive the most sunlight. The soil in shadier areas tends to retain more moisture.


Soil moisture is a critical measurement for any gardener to take. When soil is kept consistently moist, plants are able to grow their best. Conversely, plants with dry soil struggle to uptake nutrients and can even wilt and die. There are many ways to measure soil moisture, but the easiest method is to simply use your fingers. Simply dig a finger into the soil about 6 inches deep, and then remove it. If the soil is moist, your finger will be wet. If the soil is dry, your finger will be barely moist.

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