Indoor gardening
We learn about the Carbon Cycle in Elementary school so when I talk to clients I’ve found the topic of CO2 often gets washed into the “yeah, yeah, I know” category. But what many people don’t realize is that extra lighting provided to your indoor garden may be going to waste without it. Plants use the light energy to combine carbon dioxide and water, which it turns to sugars to form carbohydrates, and then mixes with the nutrients in order to increase biomass. This means that you can pump your garden full of LED grow lights, water, and nutrients but if the CO2 isn’t available to put this process in motion the plants can’t use any of it.
The number one limiting factor in efficient photosynthesis is carbon dioxide. What this means is- although plants need light, nutrients, and water; it is the make-up of our air that is holding the majority of plants from reaching their full potential. For centuries we have grown our food in fields where we had little choice but to accept the level of carbon dioxide in the air. By placing compost around the plants we were able to reap some of the benefits of enhancing CO2 concentrations but there was no way to trap the CO2. As more and more growers choose to control their environment, it has become more practical to increase ambient levels of carbon dioxide.
Plants need CO2 much in the same way that we need oxygen. We can maintain ambient levels through proper ventilation but plants are able to utilize much more than nature provides. The average air we breathe is 300-400 ppm. Plants will stop growing at 150 ppm. In a closed growing environment this level is quickly reached as the concentration is constantly depleted by the process of photosynthesis. Researchers studying the effects of CO2 on plants have found that under otherwise optimal conditions- we can gain a 40% increase in yield by simply raising the CO2 level to 700-1600 ppm.
So how do you do it? There are CO2 sensor kits that range from $20 and up to gauge the concentration of CO2 in a room. It is important to know the level of CO2 before you start adjusting. Levels of 20,000 ppm will make humans pass out and 2500 ppm is enough to give you a headache. Ventilation should protect against these high concentrations but better safe then sorry. The most common method of boosting CO2 you use already if you are spending time with your plants. Our breath contains 35,000 to 50,000 ppm of CO2.
There are many affordable methods of adding CO2 if you aren’t always there to breathe. Small areas could simply utilize a compost bucket with a gas valve. You can create your own CO2 by mixing sugar, water, and yeast. Either of these methods will need a low level oscillating fan to circulate the CO2 which naturally sinks to the ground. If you are willing to invest, there are some great injectors and generators available in most hydro shops. In closing, don’t overlook the CO2 levels in your garden. Plants won’t grow without it.
