Once we’ve decided to get into cannabis gardening, we must face an issue that may send shivers down our spines if it’s our first rodeo with plants: how to water cannabis. Water and nutrients are vital for cannabis growth. Knowing when and how to water this plant is of utmost importance in order to keep our plants as fit as a fiddle. While cannabis shows some resilience to water shortage or excess, these two scenarios may result in detrimental to the plant and stunt its growth. Cannabis water demands depend on the temperature, its strain, its features, flowering, and the size of leaves. Yet, there are some general tips that will help you clear your doubts.
How Often Should I Water Cannabis?
Most growers water cannabis every 2-3 days. This allows the soil to dry out quickly, as it should. Moist soil is a breeding ground for mould and causes root rot. An easy way of checking moisture consists in dipping your finger in the soil up to your first knuckle to see how moist it feels. If the soil feels dry, it’s most probably time to water your plants. On the other hand, if the soil feels too moist: beware! Most likely, this would cause the plant to stunt its growth or die.
The Right Amount of Water
Although each grower should learn how much water should be supplied depending on factors such as location, climate, and time of the year, it is sensible to observe the following guidelines: watering to 1/4 of the pot capacity, bearing in mind the size of the plant, and—as soon as the seed has been planted—watering every 2 to 3 days. In the case of transplanted plants and during the whole vegetative growth period, water should be applied a few times a week. After budding, the plant needs more water than ever—you should water every two days.
The Best Water for Cannabis
Most preferably, cannabis plants should be watered using unchlorinated water, i.e. rainwater, distilled water or river water. Since these types of water are not always available, we could also let tap water sit in so that chlorine evaporates. Water’s pH or potential of hydrogen should be kept an eye on when watering and is vital for nutrients to be efficiently absorbed.
Indoor Watering and pH in Hydroponics
The term pH refers to the potential of hydrogen of a substance, expressing that a substance is more acidic or more alkaline, which determines its solubility when interacting with some substances or others. The pH level of soil, irrigation water, or fertilisers directly affects the nutrient absorption power of plants. Cannabis can take in the nutrients it needs within a pH range of 6 to 7, ideally 6.5—that is, neutral but slightly acidic. As we depart from those values, growth issues and problems of lack or excess of nutrients may arise. Some fertiliser brands warn that irrigation water is usually a bit alkaline, so they produce more acidic products to balance this out. Some growers even adjust the pH of water and other nutrients themselves so there’s one less thing to worry about when keeping a watch on the plant. In the case of hydroponics, optimal pH levels are rather lower than those used on the ground: between 5.5 to 6.5. Indoor growers usually check alkalinity on a regular basis and adjust it depending on technical recommendations for each type of plant.
The Best Time to Water
Should I water during the day or night? In or out of the sunlight? You should never water in direct sunlight because plants may scorch. What’s best is to do it during the first hours in the morning and using water at room temperature, moisturising the soil, avoiding water to leak from the bottom of the pot. Some growers dissolve honey in water the last days before cutting buds off so that they are a little sweeter. Flushing is crucial to remove excess nutrients and obtain tastier and more balanced buds.