By Sugary Tips
When considering environmental factors influencing the growth of plants, pH is one of the most important. Even beginner gardeners know the importance of light, temperature and moisture. But in order to rise to the higher levels of gardening accomplishment, one must consider the finer, more subtle influences; ones that our senses cannot well discern.
Reference to “pH” is the measurement of acidity compared to alkalinity. This scale runs from most acidic at zero and goes up to the most alkaline or base at 14. For your cannabis garden, you are looking for about a 6.0 to 6.5, right in the middle. Neutral is considered to be 7.0. So a perfect cannabis growing medium would be considered a slightly acid solution. The pH scale is a logarithmic scale simlar to that used to measure earthquakes called the Richter scale. This means that the difference between 6.0 and 7.0 is actually a factor of 10 times. So to go from 6.0 to 6.1 is to double the alkalinity. From 6.0 to 6.2 is 3 times. When your acceptable range is from 6.0 to 6.5 that is an enormous range, really, but occupies a occupies a relatively small niche in a very large spectrum.
I was explaining this concept to a friend of mine the other day and we had one of those epiphany moments. He had been a pool maintenance guy and wondered why it was so easy to overshoot when you are adjusting the pH. Let’s say you start off with a reservoir full of really alkaline water, like I have that clocks in around 7.8 to 8.4 (depending on how my well fells that day). I give it a quarter cup of pH down adjusting solution and that might get me down into the low sevens. Then I add about half as much pH down and that gets me down to about 6.5. Just a dribble at this point could push me down into the low sixes where I want to be, but another drop or three and I’m plummeting down into the low fives.
Why Are PH Levels Important For Growing Cannabis?
A lot of plant metabolism has to do with the absorption of micro-nutrients which are dissolved in the soil or watering solution. The micro-nutrients cannot be dissolved and be available to the plant if the pH is too far off their normal range. This is very similar to how you see a drop-off in plant metabolism with the decreases or increase in the temperature away from the optimal growing conditions range. Just a 5° shift in the temperature will cause a 20% decrease in metabolic rate. So 10° equals 40% and 15° equals 60%. You can see how just small shifts in environmental factors like temperature, pH, moisture, ect. do cause dramatic changes in the plant’s ability to uptake nutrients.
A lot of plant metabolism has to do with the absorption of micro-nutrients which are dissolved in the soil or watering solution. The micro-nutrients cannot be dissolved and available to the plant if the pH is too far off their normal range. This is very similar to how you see a drop-off in plant metabolism with the decreases or increase in the temperature away from the optimal growing conditions range. Just a 5° shift in the temperature will cause a 20% decrease in metabolic rate. So 10° equals 40% and 15% equals 60%. You can see how just small shifts in environmental factors like temperature, pH, moisture, ect. do cause dramatic changes in the plant’s ability to uptake nutrients.
