As a cannabis grower, you should learn what pH means and how to manage its correct level in the medium so that your plants can get all the required nutrients and stay healthy. Even if you plant the best cannabis seeds (visit https://askgrowers.com/ to read about the tips on choosing them), imbalanced pH won’t allow your seedlings to get enough nutrients and minerals to grow properly. With this article, learn how to check and maintain a suitable acidity level.
It may seem a daunting topic, but describing pH is necessary, especially for novice growers who buy cannabis seeds for the first time, because understanding soil pH is important to grow healthy marijuana plants.
It is an acronym for “potential of hydrogen,” measuring how alkaline or acidic a solution is. It is based on a scale that ranges from 1 to 14. Seven is considered neutral (the level of pure water). Anything below 7 is acidic (think of lemon juice and vinegar). Anything above 7 is alkaline, as in the case of bleach, soap, and ammonia.
Why is a pH Level Important for Growing Cannabis?
In the world of marijuana cultivation, pH affects and is affected by everything. Cannabis plants thrive when the pH level of the growing medium lies in a specific range, which is slightly on the acidic side of the spectrum; otherwise, plants will be unable to uptake certain nutrients. “Nutrient lockout” will lead to a nutrient deficiency and may cause serious plant health problems, including necrosis and death of the plant tissue.
For example, the solubility of manganese, zinc, and iron increases because of a low pH level, making them more available to plants but leading to toxicity. When pH increases, some nutrients become less soluble and less available to cannabis plants. Too alkaline or too acidic conditions can be destructive to plant cells and tissue, resulting in stunted growth, changes in cannabinoid and terpenoid profiles, and lower yields.
Growing in Soil, Hydroponics, and Soilless Cultivation
In those places where cannabis grows in the wild, the soil is naturally slightly acidic, and home-grown marijuana plants prefer the same type of slightly acidic environment.
The ideal pH level for growing in soil is between 6.0/6.3 and 6.8/7.0. Natural fluctuations within this range are allowed. This pH level provides a healthier environment for microbes present in the soil, meaning more organic matter has been broken down into usable nutrients for plants. If you grow marijuana without mineral nutrients, pH levels won’t be as significant.
For hydroponics, coco, perlite, and soilless cultivation, the optimal pH level will be more acidic, ranging between 5.5/5.8 and 6.3/6.5. Slight fluctuations within this range are also allowed.
The ideal pH level for weed plants varies. It is different in the vegetative and flowering stages. During the vegetative phase, try to keep this level between 6 and 7 to allow cannabis plants to absorb more nitrogen, potassium, and phosphorus. It is true with regular, autoflower, and feminized cannabis seeds. The ideal pH range during the flowering period is between 6.5 and 7.5, which is suitable for flower development.
Also, different strains may have different pH requirements. Some cultivars may be more tolerant to lower or higher pH levels, while others may need a precise pH level.
How to Measure pH Levels
Cultivators should test pH levels every 2 days to maintain them optimal. It may sound complicated, but really it is not. Gardeners can use a digital pH meter, which is accurate and easy to read. First, you calibrate the device, stick it into the soil or fertilizer and get instant data.
Old-school growers prefer using a pH measurement kit with drops and testing strips, which are also super simple and don’t need calibration. You can try both methods to see which one suits you most. Measure the pH after you add nutrients because they will change the pH level of water.
For hydroponic cultivation, test water from the reservoir a few minutes after you add nutrients. Don’t worry if your nutrients are slightly above or below the optimal conditions. Only react to significant changes in pH that may reduce your plants’ ability to uptake nutrients.
It is crucial to check the pH level of your growing medium regularly. If you determine any pH imbalances early, you can minimize the risks of running into nutrient deficiencies. Plus, you’ll ensure that the money and time you’ve spent fertilizing your plants will pay off. If the pH of your water, soil, or fertilizer is far from the optimal range, you’ll need to adjust it.
You can use pH-up or pH-down products available in any grow store, from major gardener retailers, or in shops that offer cannabis seeds for sale. After you test the pH level, add a small amount of a pH-down solution to your water or nutrients to lower your pH or a small amount of a pH-up solution if your pH is low. Then, test the pH again and repeat the process until the level is ok.
If you prefer to take the natural route, you can use natural products to adjust your soil pH. The most effective mediums include compost, manure, pine needles, compost teas, worm castings, and wood shavings. They help lower the pH level of your soil gently. Vinegar and lemon juice are also efficient at driving down pH.
They need to be diluted in water to avoid damaging the plant’s roots. Limestone is one of the most common products to raise soil pH. It comes in pellet, powder, and hydrated form. Alternatively, you can use wood ash. Some natural methods take longer to act and impact plants than products on the market specially designed to adjust pH. You can utilize them if you have more time to finesse the soil.
Growing cannabis for personal and commercial use requires strict attention to detail, and maintaining the proper pH level is one of the most crucial factors. The acidity level directly affects the availability of nutrients to cannabis plants and is critical for their optimal growth and yield.
So, regular monitoring and regulating the pH of the water reservoir or soil is important to grow healthy plants. Of course, you can forget about measuring pH if you opt for organic cultivation and use natural fertilizers and organic nutrients. They will support the development of healthy microbial life in the soil/water and naturally promote the health of your cannabis plants.
By Tia Moskalenko
Tia is an experienced writer in AskGrowers, with numerous publications in Ganjapreneur and Detroit Metro Times. She is deeply interested in the cannabis industry, and her works cover a wide range of topics related to weed. She has come into cannabis journalism in the last few years and specializes in conducting interviews.