Hartley Magazine

All the latest news, hints, tips and advice from our experts

Roger Marshall

Back to magazine

Rhode Island greenhouse gardener overlooking the sea

Roger Marshall is a British born expert in greenhouse gardening who lives overlooking Block Island Sound in Rhode Island. He has written many articles on gardening in various publications and is the author of a recent book “The Greenhouse Gardener’s Manual”. He is also a yacht designer who writes about sailing and power boats.

View Other Articles

Automating Your Greenhouse

A pair of drip emitters with their spikes to hold them in the soil. Note the thick plastic pipe that runs around the entire greenhouse. Emitters are plugged into it. The tangle of lines is caused by my trying to get them aligned to take the picture.

As fall approaches, it’s time for a thorough cleaning, repainting, and upgrading of my greenhouse. One of the projects on my list this year is automating various systems. Given the large number and variety of plants in my greenhouse, maintaining the optimal environment there can be challenging. Automation can facilitate this process for watering, heating, air circulation, and humidifying, especially when it’s difficult to walk through the greenhouse to check on everything.

My Greenhouse Systems

For Watering

To automate watering in my greenhouse, I’ve installed a drip irrigation system tailored to the needs of the various plants.

  • Large Pots: From a 1-inch hose around the inside perimeter of the greenhouse, drip nozzles connect to each of twelve 30-inch-diameter pots, many containing fruit trees.
  • Medium Pots: The system also has nodes for about 20 medium-sized pots.
  • Small Pots: The remaining 50 to 60 small pots (4 to 8 inches in diameter) are grouped together for easy-access watering, which can be done manually.

This setup allows for efficient, targeted watering, ensuring that each plant gets the amount of moisture it needs.

For Heating and Air Circulation

Heating is crucial during winter when temperatures here in New England can get as low as 10oF (about -12oC). I use an electric blower-style heater, which is thermostat-controlled. This system not only eliminates the fire hazard of an open-flame heater; it also keeps the air circulating, which is important for maintaining a healthy environment. As a backup in case of a power outage, I have a manually-operated kerosene (paraffin) heater.

For Humidity Control

The heat mat is controlled by a thermostat plugged into an outlet. The sensor (thick grey tube resting against the pot) is pushed into the soil in any plant pot. When the plant soil is at the right temperature the thermostat will turn the heat mat on or off.

Maintaining proper humidity levels is vital for plant health. Fortunately, my coastal climate keeps humidity fairly high throughout the year. Even during winter, when outdoor humidity is lowest, my greenhouse humidity typically stays between 50-60% as all the plants transpire. Nevertheless, I may still consider adding a misting system if needed.

Suggestions for Automating Greenhouse Systems

To automate your greenhouse, you need not look much farther than your smartphone. Both Apple and Android phones have Home apps that serve as centralized hubs for monitoring and managing your smart home devices remotely as well as automating their activities. You can use these apps to monitor your greenhouse as well. For example, you can set up an auto-system for your drip irrigation to stop watering when adequate moisture is detected, or an auto-system for your lights to turn on when the sun sets and turn off a few ours later. These apps allow you to interconnect various smart devices, such as thermostats, lights, and watering systems, enabling you to monitor and manage your entire greenhouse environment from anywhere.

For more advanced automation, platforms like Zapier can be integrated to connect smart devices to a wider range of online services, allowing for more complex workflows. For instance, the platform could send notifications when your greenhouse security camera detects movement, perhaps alerting you to activity by those pesky neighborhood cats or mice. Or, if you love data, it could automatically log information to a spreadsheet from your greenhouse’s various sensors. This level of automation brings an added layer of intelligence to your greenhouse, making your smart devices work harder and more extensively together.

 Some Tech Options to Consider

A Nest smart thermostat can be hooked up to turn on a heater to control the greenhouse temperature.

Smart Thermostats

Ecobee Smart Thermostat: With its advanced sensors, this thermostat can detect temperature, humidity, and even occupancy, ensuring that your greenhouse maintains optimal conditions without manual intervention. You can set schedules, adjust temperatures remotely, and receive alerts if the climate inside the greenhouse changes unexpectedly.

Google Nest Thermostat: This popular smart home thermostat can detect both temperature and humidity. It can also learn your preferences over time, making automatic adjustments to maintain the conditions you have shown that you desire.

Amazon Smart Thermostat: Although lacking some of the features found in more advanced thermostats, this can be a budget-friendly choice for a greenhouse.

Smart Plugs for Lighting and Other Devices

Eve Energy Smart Plug and Power Meter: Eve Energy is a HomeKit-enabled smart plug that allows you to control and monitor power usage remotely. It also supports schedules and automation rules. It’s perfect for controlling greenhouse grow lights, fans, or other electrical devices.

Meross Smart Wi-Fi Plug: This plug offers reliable performance with Apple HomeKit integration, allowing you to control devices via Siri, the Home app, or automated schedules. Its affordability and easy setup make it an excellent choice for automating your greenhouse lighting or other devices.

Smart Watering Systems

Rachio 3 Smart Sprinkler Controller: Rachio’s smart sprinkler system offers weather-based watering schedules, which can save water while ensuring your plants get the moisture they need. Compatible with Apple HomeKit, it’s great for optimally automating a greenhouse’s watering system.

Eve Aqua Smart Water Controller: Eve Aqua allows you to control your irrigation system with Apple HomeKit. It can be programmed to water your plants at specific times and integrates seamlessly with the Apple Home app (although it doesn’t support Google).