Vernier Software and Technology
Vernier Software & Technology

Plant Waterer


All living things need water to survive, especially plants. Since plants are about 90% water by weight, they will physically wilt if they do not get enough water. The type of plant, its age, and its environment determine the amount of water it needs every day. A succulent or drought-tolerant plant (such as a cactus) requires less water than a non-succulent plant because a succulent has thick leaves and stems that can retain moisture. Light, temperature, humidity, and soil type also affect the amount of water plants use every day. Many homeowners install automatic watering systems to keep their lawns and gardens green during the summer. Sprinklers turn on in the early morning and stay on for a pre-set period of time. However, a watering system based on time is not a healthy solution for house plants. Their soil can quickly become saturated, which can be as bad as not enough water.

Design Requirements

In this project, your challenge is to design and build a sensor-controlled watering system for a potted house plant. Your device should automatically water the plant when the soil is too dry and stop when the soil is wet. You will use a Vernier Soil Moisture Sensor to monitor the moisture level of your plant’s soil. The soil will be considered “too dry” when the moisture level falls below 20%, and sufficiently “wet” when the moisture level rises above 28%. When building your device, you should incorporate easy access to a refillable water reservoir. Prior to operation, you must bury the sensor in the plant soil by hand. The sensor will remain in the soil for the life of the system.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Additional Requirements

You will also need NXT Sensor Adapter and a LEGO MINDSTORMS EV3 robotics system.

Vernier Engineering Projects with LEGO® MINDSTORMS® Education EV3

See other experiments from the lab book.

0Introductory Project Robot Walker
1Data Display and Acidity Tester
2Plant Waterer
3Audio Assistant
4String Tension Tester
5Aquarium Monitor
6Cartesian Diver
7Sunscreen Tester
8Battery Tester
9Solar Tracker
10Magnet Detector
13Shell Game

Experiment 2 from Vernier Engineering Projects with LEGO® MINDSTORMS® Education EV3 Lab Book

<i>Vernier Engineering Projects with LEGO<sup>®</sup> MINDSTORMS<sup>®</sup> Education EV3</i> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

Buy the Book

Go to top