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Nutrients

Nutrients

If you’ve decided to start growing cannabis for the first time, trying to figure out the best nutrients for your setup can be very confusing. There are many nutrient companies, and each one creates multiple types of nutrients with different purposes. The most important thing is to make sure you give your plants the right amounts of nutrients at the right time. There are two main life stages for cannabis plants, and each stage has different nutrient requirements.

Chart diagram showing the optimal NPK nutrient ratios for growing cannabis or medical marijuana

Where is this information? Most nutrient bottles display 3 numbers, often called N-P-K, which stands for NitrogenPhosphorus and Potassium

Why “K” for Potassium? The atomic symbol of Potassium is “K” from Neo-Latin kalium.

In other words, you want to use a “Vegetative” (high Nitrogen) or “general purpose” nutrient formula for the first stage of life known as the vegetative stage. If using high-quality soil, you can skip vegetative nutrients for the first 3-4 weeks while your plant uses up the nutrients in the soil, otherwise you should start with vegetative nutrients around the time your plant opens its first leaves.

Use a “Bloom” (low Nitrogen) nutrient formula with plenty of P & K for the flowering stage. Start using bloom nutrients when buds start forming to make sure your plant gets plenty of Phosphorus & Potassium, which are crucial to bud development. Phosphorus tends to increase the number of flowers, while Potassium helps increase the bulk/weight of flowers. Be careful, though because going overboard with either one can burn your plants!

Most cannabis nutrient bottles prominently display 3 numbers, called "NPK" which stands for Nitrogen, Phosphorus and Potassium. These numbers tell you the ratio between each of these nutrients in the bottle

The main thing is to avoid giving too much Nitrogen in the flowering stage, as it can discourage bud development in the flowering stage and add an unpleasant taste to buds, which is why a general purpose plant nutrient isn’t a good choice in the flowering stage. In a pinch, nutrients for “cactus” or “succulents” can be used in the flowering stage until you get better nutrients because they usually have low amounts of N and plenty of P & K. 

Note: Don’t use any type of time-released nutrients (like fertilizer spikes, or “slow release” Miracle-Gro soil) because they deliver too much N in the flowering stage and may reduce bud growth.

Cannabis needs plenty of P & K to make buds in the flowering stage!

The Best Cannabis Nutrients Aren’t Enough! Check the pH of your water to plants to prevent deficiencies It may surprise you that the most common reason growers get nutrient deficiencies is because the pH is too high or too low. This happens even if the right amounts of nutrients are present, because your weed simply cannot absorb the nutrients if the pH isn’t in the correct range.

Optimum cannabis pH

Soil: 6.0 – 7.0
Coco Coir: 5.5 – 6.5
Hydroponics: 5.5 – 6.5

Checking the pH will make a huge difference to your grow by keeping plants vibrant and healthy. It only takes a few minutes each time you water your plants! If you get a digital pH pen, it only takes seconds to test your pH

Organic vs Chemical Nutrients

This is a common question we get at Grow Weed Easy: What are the major differences between organic and chemical nutrients? It’s not a matter of which one is better, because they’re good at different things.

Organic Nutrients

Many growers believe organic-based nutrient systems will create the most fragrant and “smoothest” buds. Some of the best benefits to smell and taste seem to come from using composted soil that’s been amended with nutrients from natural sources. This creates a living soil with colonies of beneficial microorganisms, and is often associated with a bolder taste and smell in buds. However, watering your plants with liquid nutrients that just happen to be organic will likely not get the same level of results.

More Natural – Especially when growing in a living soil, you’re creating a home for your roots that is as close to nature as possible (only better because you’re making sure your plant gets everything it needs)

Chemical Nutrients

  • Faster Growth – Chemical nutrients provide nutrients to plants in the most easy-to-absorb forms possible. This results in somewhat faster growth than if the nutrients have to be broken down in the soil by a colony of microorganisms before they become available to your plant.
  • Only Choice for Hydro – These are the best cannabis nutrients for hydroponic systems because they are less likely to cause stuff to grow in the water reservoir. However, chemical nutrients can also be a great choice for soil or coco because of the increased potency and faster growth.

Don’t want to use nutrients at all? Learn how to compost your own super soil (or buy super soil pre-made online)! Super soil compost contains all the nutrients your plant will need from seed to harvest so you just need to add water, and as an added bonus, with composted super soil you don’t need to worry about maintaining your pH! Instead, the composting process develops a colony of microorganisms in your soil that will automatically take care of the pH for your plants (like in nature), while slowly providing nutrients on demand.

Super soil compost has been amended so no additional nutrients are needed. Just add water!

Learn how to mix up your own marijuana super soil!