Indoor Plant Nutrition and Fertilizers

Start with quality soil

In general with cannabis fertilization, starting with high-quality, organic soil gives the plants the food they need to feed themselves.  Liquid and foliar supplements should be used in moderation to enhance the grow.

Fertilizer basics

Understanding the nuances of cannabis fertilization is often the biggest stumbling block for new growers, so we’re going to break it down for you. Whether it’s your first grow, or you’re looking for a refresher, we’ve got you covered.

Three letters you’ll hear a lot are N-P-K, in that order. They stand for nitrogen, phosphorous, and potassium, and they are three essential building blocks for plants.

In general, plants respond well to high levels of nitrogen during the vegetative growth phase. However, when growing cannabis plants, nitrogen levels must be lowered during flowering while potassium and phosphorous increase.

During flowering, potassium and phosphorous are responsible for producing big, flavorful, and potent buds. Because this plant species is so responsive to nutrients, many newcomers make mistakes with fertilization -usually by overdoing it – and wind up with a disappointing harvest. Fortunately, there are some easy rules for getting fertilizing right.

N-P-K levels through the cannabis lifecycle

Good-quality, organic liquid and foliar fertilizer products usually have balanced amounts of micro-nutrients, but vary in the amount of N-P-K they deliver. Fertilizers list N-P-K percentages as three numbers separated by dashes on the label of all fertilizer products.

During the vegetative growth phase, cannabis responds well to careful feeding with higher nitrogen fertilizer products like organic fertilizers for tomatoes with levels of about 8-5-5.

When flowering starts, nitrogen should be reduced and increasing phosphorus and potassium levels will help improve flower growth and development. Continuing with heavy nitrogen feeding during flowering reduces the quality of the flower buds.

Macro & micronutrients

Aside from CO2 and water, nitrogen, phosphorous, and potassium are the three nutritional elements plants need in the high quantity. We call nutrients needed in abundance macronutrients.

However, there are other essential nutrients that healthy cannabis plants need at much smaller levels, called micronutrients. Calcium, magnesium, and sulfur are needed in smaller amounts, and molybdenum, boron, manganese, chlorine, iron, copper, zinc, and nickel are required in trace levels.

These micronutrients can be found in many plant supplements, which we carry in our shop.

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