Things to consider when choosing the best soil moisture sensor for plants

A quality soil moisture sensor for plants can be a worthwhile investment for both indoor and outdoor plant health—fortunately, they don’t have to be expensive to deliver benefits. The best soil moisture meters are accurate and sturdy, providing precise information in almost any soil condition. When choosing a hygrometer, consider its intended use, display type, growing medium, and any other measurements or features that may help simplify plant maintenance.

An soil moisture sensor for plants

An soil moisture sensor for plants can be a useful tool for growing anything from potted fiddle leaf figs to a budding vegetable patch. Many soil moisture meters are equipped for both indoor and outdoor use, but there are some features to consider. Probe lengths can range from about 6 to 15 inches, and sometimes even longer, which is one of the factors in determining which moisture meter is right for an indoor or outdoor garden.

Houseplants tend to be smaller and grow in looser potting soil. A hygrometer with a short probe may work well for houseplants that are usually not too deep. Short probes are easier to store and durability is less important for indoor use.

For outdoor plants, durability may be a more important characteristic. Consider a meter of solid construction—models with probes that are at least ¼ inch thick should be more resistant to bending, or models with stainless steel rather than plastic housings. Longer probes are generally better for outdoor use, especially for certain jobs, such as checking a pile of compost. The probes on compost moisture meters are also usually thicker, about 5/16 inch in diameter.

Soil moisture meters are available in both analog and digital models. For the average gardener, analog meters are a cost-effective option. These gauges are simple, usually displaying humidity readings on a scale of 1 to 10, sometimes color-coded for easy viewing. The analog meter requires no batteries and works right out of the box.

Soil moisture sensors for plants can include a range of handy features, but they do come at a cost. While pricier than simple analog gauges, they are more accurate, easier to read, and may have remote or smart connectivity capabilities. Digital Soil Moisture Meter requires battery or USB charging.

Regardless of the hygrometer type, a clear, easy-to-read display is helpful. Some gauges have an angled display on top of the unit for easier viewing when in soil.

soil type and texture

Soil type and texture can affect the choice of soil moisture meter. For harder soil types, like heavier clay, look for a gauge with a very sturdy probe. Although most gauges have aluminum or steel probes, some more fragile and thinner options may bend or dent in harder soils. For these soil textures, a probe at least ¼ inch thick is a better choice.

Since any soil moisture meter can handle loose potting soil intended for indoor plants, the probe is more of a concern for outdoor plants. However, regardless of the gauge type, it is best not to use a lot of force to insert the gauge into the soil. If the user detects considerable resistance in any soil type or texture, remove the gauge and try a different position.

Also keep in mind that high sodium levels in the soil can cause inaccurate readings, and testing the soil for salinity may be helpful if plants are not thriving. When using a soil moisture meter in soils affected by salinity, the meter may indicate higher moisture levels than it actually does. In these cases, physically feeling the soil can help determine if the readings are on the right track.

Multifunctional Soil Monitoring Equipment

Multifunctional soil monitoring equipment can include a range of measurement functions. These handy gauges can provide a snapshot of soil conditions, warning of potential problems. Additional sensors can measure pH, light levels and ambient temperature.

Humidity: The simplest meter is a hygrometer with a moisture sensor that measures soil moisture. They typically display moisture content on a color-coded scale, decimal or percentage value from 1 to 10, where lower numbers indicate drier soil and higher numbers indicate wetter soil.
pH: Some moisture meters include pH sensors to measure the pH of the soil and gain insight into whether the soil is acidic or alkaline.
Light Levels: Different plants prefer different levels of light. A lux meter measures the intensity of light in a specific area.
Ambient temperature: Some hygrometers also measure the ambient temperature of the surrounding area. This measurement can tell when the seasons are changing and indicate the right time to plant or prune certain plants.
accuracy
Accuracy is obviously important for hygrometers. For the most accurate readings, consider using a digital hygrometer. Some digital gauges display soil moisture content to decimal points or percentages, making them more accurate than analog gauges that have a scale from 1 to 10.

Calibration features also help improve accuracy. User calibrated gauges allow calibration to be adjusted for different conditions, such as gardening or composting, humidity conditions, or the specific water needs of certain plants. Also consider the proper probe length for the intended use. For example, compost hygrometers tend to be much longer than plant hygrometers. Most meters have the humidity sensor at the end of the probe – not along the entire length – so the correct length is important for accurate readings. The probe must be long enough to reach the area to be measured. Probe lengths can vary from a few inches to as long as 24 inches.

Intelligent Technology

Like many devices, soil moisture meters can include smart connectivity features. The Smart Soil Moisture Meter connects to a smart device via Bluetooth to display the results. This opens the door for a variety of additional features, such as tracking the history and progress of plants and providing tailored recommendations for each plant.

For ease of use, these smart devices often have a sensor that is always present in the factory. Users can then connect to the sensor device via the app to check soil conditions. In addition to measuring moisture levels, most of these devices also measure light levels, temperature and fertilizer levels, information that can indicate ways to improve plant care.