When applied to soil, you’re adding to the soil food web by introducing a healthy population of microorganisms that are aerobic in nature. These organisms hold nutrients, aerate soil, aid water retention, increase nutrient absorption in the cannabis plant, help grow healthy roots, and help prevent diseases.
Without adequate phosphorus, marijuana plants will show signs of undeveloped roots and might not even flower. Early signs of phosphorus deficiency shows up as a purple hue in the veins of leaves.
Phosphorus is important for producing large, healthy buds. The key role of this element is to help make nutrients available for the plant to uptake. These nutrients are used to build the structure of a plant as it grows from its roots to its flowers.
Indoor growers typically use liquid nutrients and mix them in with water before watering plants. Using liquid nutrients is usually more time consuming, as you typically have to measure and mix them in water 1-2 times a week.
Organic fertilizers and nutrients can be more forgiving than liquid nutrients. They usually contain less immediately soluble nutrients and more elements that are beneficial to soil organisms.
How to make compost tea in 5 steps.
The goal of compost tea is to introduce nutrients, fungal colonies, and beneficial bacteria to either the soil or foliage of a marijuana plant to aid growth and protect it from harmful disease, promoting bigger, stronger, and more resilient plants.
To use liquid nutrients, you’ll need a separate water tank, such as a dedicated garbage bin, to mix them into water. You’ll also need to know how much water is needed for all your plants. Depending on the amount of water you need, add the correct ratio of liquid nutrients according to the bottle’s directions.
Using organics is also great if you want to be more in-tune with your natural environment. Organic fertilizers are readily available from renewable sources and are an earth friendly option.
Because liquid nutrients are readily available to a cannabis plant’s roots, they are fast-acting, meaning they can damage plants if you feed them too much.
Liquid nutrients are typically used for indoor growing, but can be used outdoors too. Liquid nutrients are used for weed plants in soil, hydroponics, and other grow media, and can be pushed through drip lines, misters, and hoses for easy and efficient delivery.
Before building a compost tea brewer, you need to consider the size of your cannabis garden. Most homegrows use 5-gallon buckets. On the outside of the bucket, you’ll need to have an air pump connected to an aerator device at the bottom. The aerator and air pump will oxygenate water so microorganisms can breathe.
Cannabis plants need different amounts of these nutrients throughout the different stages of growth: more nitrogen during vegetative growth, and more phosphorus and potassium during flower for bud production—also called “bloom” nutrients.
In the final week or so before harvest, be sure to give your plants only water to clear any nutrient buildup in the buds—this is called flushing.
Growing high-quality weed requires more nutrients, or fertilizer, than most common crops.
Products are also generally divided into “grow” solutions, high in nitrogen needed for vegetative growth, and “bloom” solutions, high in phosphorus for flower development. You can stick to these general terms if you don’t want to get bogged down with numbers.
Calcium is responsible for keeping the structure of cell walls in a plant together. Without calcium, new growth won’t develop properly and the plant won’t function as it should. New growth will be stunted, leaves will curl, and rusty spots will show up on the plant.
The fertilization process can repeat itself year after year as the soil continually improves—next year, your soil will be even better than this year’s.
A general rule of thumb is that a vegetative fertilizer should have high nitrogen, low phosphorus, and moderate potassium: for example, 9-4-5. As a plant transitions into flower, taper off the nitrogen and focus on phosphorus and potassium—seek a ratio around 3-8-7, for example.
Commercial soil blends also exist that already contain the proper mix of these nutrients.
Magnesium acts as the central molecule in chlorophyll and without it, plants aren’t able to generate the glucose from photosynthesis. No magnesium means no energy can be converted from sunlight.
Additionally, cannabis plants derive these non-mineral elements from air and water:
You don’t want to use liquid nutrients every time you water—use them every other watering, or two waterings on, one off. It depends on the complexity of your soil and the health of your plants. Too many nutrients will damage your plants.
There are some complications in working with organic fertilizers. The main issue is if your weed plants have a nutrient deficiency, it takes longer for a plant to absorb organic powder nutrients, which can increase the damage to plants. Liquid nutrients act much quicker. Other disadvantages:
You’ll also need a 400-micron mesh bag to place ingredients for the tea. While you can buy pre-built tea brewers, you can also easily make your own for cheap.
Compost is filled with beneficial microorganisms and nutrients, and you can take it one step further by steeping it in aerated water. This process, called “compost tea,” extracts the microorganisms and soluble nutrients into a water “tea” solution.
Nitrogen is mainly responsible for a cannabis plant’s development during the vegetative stage of its life. It’s an essential part of chlorophyll and without it, a plant can’t turn sunlight into energy and it won’t be able to grow.
Potassium also triggers the production of ATP, which works to store energy produced in photosynthesis by creating glucose. This glucose is then used as energy for the plant as it grows. Without sufficient potassium, you will see weak plants starved for energy that appear burnt because they are unable to successfully regulate the exchange of CO2, H2O, and oxygen.
These micronutrients are needed as well, but in much smaller quantities:
Giving weed plants the proper amount of nutrients requires careful monitoring. Many growers start at a solution dose lower than recommended and work their way up until plants respond optimally. Too little nutrients and the plants will have stunted growth, while too many can lead to nutrient burn and lockout .
A cannabis plant needs many nutrients, and pulls these from the soil. Left on its own, with good soil, plenty of light and water, and a temperate environment, a weed plant will grow fine, but nutrients will help the plant thrive and grow healthy and strong.
Can I create my own nutrient system?
Get the trio: Grow, Bloom, Base (need all 3 bottles for all phases of growth)
There used to be a ton of organic soil nutrients in bottles (like the now-discontinued GO Box) but many options have disappeared as growers switch to using amended compost for their organic nutrient needs. Why? The organic nutrients in bottles get similar results to mineral nutrients. The biggest difference in organic growing seems to come from using actual compost and/or amended soil.
Where is this information? Most nutrient bottles display 3 numbers, often called N-P-K , which stands for Nitrogen , Phosphorus and Potassium.
Dyna-Gro Grow + Bloom is my recommended nutrient system for newbies. One bottle for veg, one for bloom. Super simple!
What’s the Best NPK Ratio for Cannabis Nutrients?
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!
Use “Grow” in the vegetative stage, and “Bloom” in the flowering stage. Organic. Claims to be usable in hydro, but I’ve only seen growers use it in soil so that’s what I’m recommending it for 🙂
Very concentrated, less is more. “Grow Big” & “Tiger Bloom” provide most of the major nutrients your cannabis needs, while “Big Bloom” has many micronutrients and beneficial compounds that help nutrient uptake and root health. This trio works extremely well by itself, just follow the feeding schedule (here’s a PDF, here’s a JPG) from Fox Farms at half-strength to start.
Use the “hydro” version of Fox Farms nutrients when growing in coco coir. Two bottles are the same as the soil trio, but the “Grow Big” bottle is formulated slightly differently for a soilless grow. Follow the feeding schedule (here’s a PDF, here’s a JPG) from Fox Farms at half-strength to start. Generally, the Fox Farms nutrient system will prevent Cal-Mag deficiencies, but it’s good to have extra Cal-Mag on hand just in case whenever growing cannabis in coco coir, if using filtered water, or if growing with LED grow lights.
Why “K” for Potassium? The atomic symbol of Potassium is “K” from Neo-Latin kalium.
From a grower: “Botanicare KIND is like the opposite spectrum [of the Botanicare Pure Blend series]. The Base is just Nitrogen and Calcium. Grow and Bloom both have most of the minerals in them, along with things like sea kelp. The Bloom is also 0-6-6. Grow at 2-2-4. So quite literally you can call the shots on Nitrogen and Calcium. That level of control hasn’t been around a great deal in our market. For the savvy grower, this is a pretty nice tool.”
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!
Follow the instructions on the side of the bottle at half-strength for great results in soil or coco. It’s recommended to also use a Cal-Mag supplement if using filtered water, growing in coco, or using and LED grow light (all tend to increase the Cal-Mag needs of your plant). I prefer the GH version called CaliMagic, and use at 1 tsp/gallon.
Honorable Mentions – I haven’t tried these nutrient brands yet, but they are popular for growing cannabis.
Examples of Good Can nabis Nutrients.
A cannabis plant turns pale all over (left) when it needs higher levels of nutrients overall. If plant is a healthy green (right), stick to half the recommended dose.
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.
One Last Tip…
Name of base nutrients for…
Botanicare is a great company that’s been around for as long as I’ve been growing, and whose supplements I’ve been using for years (specifically, their Hydroguard supplement is the most effective thing I’ve used to prevent root rot in a hydroponic setup). Best for…
Check out a grow journal using the FF trio for Soil!
Super soil compost has been amended so no additional nutrients are needed. Just add water!
Organic vs Chemical (Synthetic) Nutrients.
Recommended Organic Nutrients.
Too high levels of nutrients causes…
For the best results, your cannabis needs the following nutrient ratios…
This list of nutrients has been extensively tested by real marijuana growers and each system is known to produce great results. Here are several examples of trustworthy nutrient brands that work well for growing cannabis.
Organic cannabis growing is rewarding!
House & Garden – Often difficult to find online!
How to Adjust pH in an Organic Soil Grow (regular PH Up and PH Down can harm the natural balance of the soil)
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. As an added bonus, with composted super soil you rarely 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 to an extent (like in nature), while slowly providing nutrients on demand.
Calcium and magnesium are often overlooked when discussing the growth of the cannabis plant. It is common to find them together in a single Cal-Mag supplement, which generally contains iron as well. These nutrients are essential to the process of photosynthesis, which involves creating energy from light. Magnesium is particularly crucial for photosynthesis; it is the central atom in the chlorophyll molecule.
If you think that nutrient options are confined to marijuana plants that grow in soil , you are wrong! There are also a variety of hydroponic options, which tend to muddy the waters for the uninitiated. But fear not! We’re here to provide an easy guide to selecting the best nutrients for growing marijuana and producing fantastic yields.
There are 17 essential mineral elements for plant growth broken up into macro and microelements or nutrients.
The macronutrients required for plant growth are:
Certain types of water don’t include large amounts of calcium; this makes them a poor choice if using a hydroponic system. You can treat a deficiency by using a calcium-rich substance such as lime.
Marijuana plants use magnesium in very high amounts. If you believe your plants aren’t getting enough, use Epsom salts to deal with the issue. Make sure you distinguish between an iron and magnesium deficiency. Otherwise, you could end up over-fertilizing your plants.
Now, let’s take a look at 11 important nutrients for marijuana plants, along with symptoms of deficiency.
Please note that most nutrient deficiencies are due to excessively high or low pH levels in your water. Ideally, soil-grown marijuana plants will have a pH of 6.0-7.0. The range drops to 5.5-6.5 if you use coco coir as a growing medium or if you are growing hydroponically . When the pH is at the wrong level, it reduces the plant’s ability to absorb these nutrients.
If a marijuana plant doesn’t receive enough of a nutrient, it will show signs of a deficiency. Let’s explore this issue in greater detail below.
Your marijuana plants need calcium, as it is a crucial aspect of cell integrity and overall growth. Calcium helps with the flow of nitrogen and sugars throughout your plants. It is unusual to experience calcium deficiency when plants are grown outdoors . However, it can happen when you grow them in plant mixes.
What Elements Does a Marijuana Plant Require for a Successful Growing Cycle?
Nitrogen is one of the most common nutrients in cannabis, and growers are aware of its importance. Despite this fact, nitrogen deficiency is common. It plays a significant role in most plant functions, including amino acid production and photosynthesis. Although your plants need nitrogen throughout their life cycle, it is especially important during the vegetative stage.
Although sulfur deficiencies are uncommon, they can occur if your fertilizer or soil doesn’t already have enough of it. Sulfur is an essential nutrient because it helps plant respiration and the synthesis and breakdown of fatty acids. If your soil or water has an excessively high pH, it could result in phosphorus loss. This is a major cause of sulfur deficiency.
Despite its importance, potassium deficiencies are common. If you use a natural fertilizer such as bat guano, please note that potassium is the least abundant nutrient of the big three. Fixing major deficiencies requires a water-soluble fertilizer high in potassium.
A mobile nutrient can move from one part of the plant to another as and when needed. If a plant has a mobile nutrient deficiency, parts of it accumulated in old leaves move to new leaves to make up for the shortfall. This is why the first sign of mobile nutrient deficiency appears in the oldest leaves at the plant’s base.
Maintaining higher proportions of P and K is critical when flowering. This is because the plants use larger amounts during the flowering stage than during the vegetative stage.
What About Cannabis Nutrient Deficiencies?
If you allow a phosphorus deficiency to run amok, the effects are potentially devastating. Your plants will experience stunted growth, poor yields, and low resin production when they become mature. Make sure you use a fertilizer with a high amount of phosphorus or a bloom fertilizer.
Many novice growers are unaware that there are ‘mobile’ and ‘immobile’ nutrients. There are also primary, secondary, and micronutrients. The difference between mobile and immobile nutrients depends on whether they can be translocated once the marijuana plant assimilates them.
You can correct a deficiency by purchasing fertilizer with the right NPK ratio. Quick treatments include urine and bat guano. If you spot a nitrogen deficiency, act fast because your plant’s yield will be significantly affected otherwise.
Your marijuana plants require zinc for sugar and protein production. This nutrient is crucial for the formation and retention of chlorophyll. It is also necessary for strong stem growth. Zinc deficiencies in marijuana are relatively common and manifest in significant structural changes in your plant.
Immobile nutrients stay in the same place once the plant assimilates them. You will spot signs of immobile nutrient deficiency in young leaves near the plant’s top and outer branches.
While marijuana plants don’t need a large amount of sulfur, it is still considered an essential macro element. As well as aiding enzyme formation, it helps to construct proteins. Sulfur is also pivotal in the development of chlorophyll molecules. If your plant is deficient in sulfur, calcium, magnesium, or iron, it can display symptoms like yellowing or dying leaves.