Wi-fi monitoring systems have revolutionized the way gardeners can manage greenhouses. Nick Cardenas, whose garden is featured in the 2024 winter issue of Northern Gardener®, installed one in his greenhouse and loves that he can monitor conditions wherever he is—even overseas. If trouble arises in the form of abnormal temperatures or humidity, he can ask someone to remedy the situation or fix it himself if he’s at home. He no longer limits how long he’s away due to worrying over finding dead plants when he returns.

Greenhouse monitors constantly relay information

Monitoring systems provide continuous, real-time oversight of crucial environmental factors, such as temperature, humidity and light levels. Owners simply preset their desired temperature and humidity ranges and receive immediate alerts whenever levels deviate from those numbers. Many units also offer comprehensive data gathering and reporting features that can be helpful in identifying patterns and areas for improvement. Although there is an initial investment in the system, owning one can optimize energy use in the greenhouse, reduce operating costs and might even end up paying for itself.

How greenhouse monitors work

Most small greenhouse systems consist of one or more wireless sensors placed in the structure. Nick has his hanging from the ceiling in the center of his greenhouse. Some homeowners buy extra sensors to also monitor conditions in other locations such as garages, motorhomes and basements.

Here is a quick summary of how greenhouse monitors work:

• The sensors continuously collect data on factors such as temperature, humidity, light levels and soil moisture. More expensive systems offer greater monitoring capabilities, but a simple relatively inexpensive system is usually sufficient for the home gardener.
• Advanced systems transmit data wirelessly to a central gateway or hub, while simpler systems send the data directly through a cloud service.
• Some advanced units use the sensor data to automatically adjust greenhouse equipment such as fans and heaters.
• Gardeners access the information through their phones or computers, allowing for remote monitoring and control no matter where they are.

Greenhouse Monitor System Options

When choosing a greenhouse monitoring system, think about the features you need that contribute to the health of your plants and their longevity, such as:

• Wi-fi connectivity; this is important for most people, but non-Wi-fi systems are available too.
• Use of a mobile app—such as on your smart phone—for on-the-go monitoring
• Customizable alerts and notifications
• A single monitoring system to connect to and gather data from various types of sensors simultaneously
• The ability of a system to collect, store and clearly present data on your device
• Integration with any other greenhouse control systems

Recommended Greenhouse Monitoring Systems

Many wi-fi monitoring systems are readily available online. Nick Cardenas chose a Govee Wi-fi Thermometer Hygrometer system that offers real-time monitoring and alerts him if temperature or humidity differs from the preset ranges. Other systems offer historical data logging with no subscription fees and a longer battery life. Some even offer protection for unstaffed greenhouses without broadband internet, using cellular or Bluetooth technology.

Check the costs. Often, they are fairly inexpensive and range in price from around $40 upwards to a few hundred, depending on the information they offer and whether they can control a variety of greenhouse devices such as fans and heaters. Some systems offer free monitoring without additional subscription fees while others have added costs, often for optional services. Most gardeners need only purchase a basic system to reap the benefits they offer.

The key is to determine your needs and your budget, look at reviews and choose the system that works for you.

Diane McGann is an award-winning garden writer and serves on the University of Minnesota Extension Ask an Expert panel. She is a member of Garden Communicators International and the Washington County Horticulture Society. Diane resides in Stillwater where she maintains extensive perennial and shade gardens on her 4 ½ acre property.