Energy Consumption

The tunnel temperature is key for controlling growth rates, thus energy consumption. We'll use ventilation to do that.

The warmer, the faster it grows.

Careful though. Too high a temperature and it exhausts the plant's energy storage. The plant gets all spindly. Eventually, it cannot maintain growth and focuses on fruits that are already ripening. New fruits abort. This is why blossoms drop before tying fruits.

But, when the temperature is too low, the plant diverts energy from growth to storage. When the storage is full (dark, curly leaves in the morning), growth stalls.

To give an idea of the importance of the temperature, every degree colder than the target slows growth by 5%! 10°F off on average means 50% less growth !

‍Now, look at the chart. It shows the temperature changes over the course of a day in a manually managed tunnel in June. The yellow band was the desired temperature.

There are drastic changes due to clouds coming back and forth, making a 43-degree spread! It’s bad for energy production and offers little control on growth rate.

Again, for cost/benefit/mental health reasons, we highly recommend automating ventilation. Otherwise, this is a lot of work, and the results are hardly worth it.

The optimal growth rate changes depending on the conditions. The next tips aim at giving you a simple starting point to protect your plant's health. In Step 6, we’ll get out of autopilot and see how to find the best temperature based on your situation.