Because of that, I encourage growers to learn about the type of nutrients and special fertilizers needed by a cannabis plant, and at least start with good soil before you get started growing if you're determined not to use any nutrients.
Cannabis plants which don't get the right levels they need, especially in the flowering/budding phase, tend to grow small and airy buds. In extremely poor conditions, some cannabis plants may just sprout a few white hairs (pistils), and never actually form any real buds at all.
Yes, you can plant weed seeds in dirt and possibly grow a plant without any fertilizers or special nutrients. But chances are that you don't happen to live in a place with very rich, fertilized soil that carries just the right blend of nutrients needed by a marijuana plant to thrive.
While cannabis plants will grow in a lot of conditions, as a farmer, you are looking to optimize the size, weight, density, potency and overall quality of your buds. In order to do that, you will need to fertilize your cannabis plants in such a way that they can produce at their best.
And if you are determined to grow organically with no added nutrients, I encourage you to learn about how you can actually compost your own organic super soil in such a way that you actually don't ever need to add any extra nutrients at all.
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.
You can add compost tea to weed plants by:
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.
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.
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.
Only start a tea when you can apply it within 36 hours of brewing it. When using as a spray, apply in the evening or morning when the temperature is low and without direct sunlight. This period is also when the stomata—pores in the plant’s foliage—are open to receive nutrients.
Nutrient solution bottles and fertilizer bags will indicate how much of the three main nutrients are in the product, in the form of N-P-K: Nitrogen, phosphorus, and potassium, For example, a product that says “10-4-4” will contain 10% available nitrogen, 4% phosphorus, and 4% potassium by weight.
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.
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.
How to make compost tea in 5 steps.
However, the benefits of compost tea are debated in the agricultural world. Many gardeners report quality results when using it, while others see no more benefit than applying straight compost. The uncertainty lies in whether or not growing and developing populations of microorganisms in the tea can actually benefit plants and prevent disease.
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.
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.
Growing high-quality weed requires more nutrients, or fertilizer, than most common crops.
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.
Additionally, cannabis plants derive these non-mineral elements from air and water:
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 .
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.
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.
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.
When using a complete nutrient system like the ones listed above, always start at half the recommended strength by the manufacturer, and only increase nutrient levels if your plant is getting pale. If you’re giving too low levels of nutrients, the entire plant will start to appear overall pale or lime green. If you have a different nutrient deficiency (diagnose your plant here), chances are it’s caused by incorrect pH, not by too-low levels of nutrients.
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.
As a cannabis grower, your goal is to give your plants the right amount of nutrients at the right time. There are two main life stages for cannabis plants (vegetative stage and flowering stage). Each stage has different nutrient requirements. Luckily, many nutrient companies make great products even though they’re all using different formulas and techniques. Here’s how they differ:
Now that you understand everything you need to know about picking the right nutrient system, check out some supplements!
What’s the Best NPK Ratio for Cannabis Nutrients?
Can I create my own nutrient system?
Name of base nutrients for…
Chemical Nutrients (including synthetic and mineral-based nutrients)
·Hydroponics / DWC/ Bubbleponics.
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 🙂
A different grower added, “Canna – I have only used their coco line, but it is the highest quality you will find.”
·Soil version (Organic)
Where is this information? Most nutrient bottles display 3 numbers, often called N-P-K , which stands for Nitrogen , Phosphorus and Potassium.
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 company creates multiple lines of nutrients and supplements for different purposes.
Examples of Good Can nabis Nutrients.
Optimum cannabis pH for..
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.
Super soil compost has been amended so no additional nutrients are needed. Just add water!
House & Garden – Often difficult to find online!
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.
Fox Farm Nutrient Trio.
This combo is a crowd favorite – many coco coir growers write in to tell us this is their favorite cannabis nutrient for growing in coco coir. Get a custom nutrient schedule from Canna or use this pre-made one [JPG].
Organic vs Chemical (Synthetic) Nutrients.
General Hydroponics offers a simple duo with one bottle for the vegetative stage, and one bottle for the flowering stage called FloraNova Grow + Bloom. This nutrient system is cheap, simple, and easy with excellent results in soil/coco/hydro. The biggest issue I have with the duo is the liquid is so thick it can be annoying to measure out.
The main thing is to avoid giving too much Nitrogen in the flowering stage, as it can discourage bud development and add an unpleasant taste to buds, which is why a general-purpose plant nutrient isn’t a good choice in the flowering stage.
Honorable Mentions – I haven’t tried these nutrient brands yet, but they are popular for growing cannabis.
Use similarly to soil or coco, just make sure to also get Hydroguard to protect your hydroponic roots from root rot.
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!
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.
Dyna-Gro Grow + Bloom – Use “Grow” in the vegetative stage and “Bloom” in the flowering stage.
Note: Don’t use any type of non-organic 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.