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What Do Marijuana Plants Eat?


cannabis plant marijuana

Picking the right fertilizer can make the difference between a plant that is merely “surviving” and a plant that is truly “thriving”. Before you start growing marijuana, you want to know what your plant will need throughout its life cycle and how to buy (or create) your own plant food supplies. Fertilizer, generally, is any element that can be introduced to soil, water, or to a plant itself that will spur healthy growth beyond what it would be without aid from the fertilizing element. Just as a human athlete needs a proper diet to achieve maximum performance levels, so does a cultivated plant require the equivalent of a healthy diet to attain maximum growth.

There are many types and forms of fertilizer, but the one that works best is the one that most effectively provides the health-enhancing nutrients that a plant needs most at that time. For now, for our purposes, forget sophisticated and often expensive soil and water testers; you can do very well using only a few proven basics and simple off-the-shelf growing products.

What Cannabis Plants Eat

The three main elements marijuana plants need are nitrogen (N), phosphorus (P), and potassium (K). All three of these are needed for strong root growth, vigorous leafing, and for lush flowers with high yields. Commercial potting soils are pre-blended with a balanced NPK ratio that will sustain a plant for the first two or three weeks. As plants grow taller and broader, supplemental nutrients are required. A great product for feeding marijuana plants is Marijuana Booster, and I suggest you check it out.

Once you reach the vegetative, or leafing, stage, a good “20-20-20″ supplement is often adequate to maintain proper growth and development; that designation stands for the percentage of nitrogen, phosphorous, and potassium infused into potting soil when it is manufactured. Indoor growers dilute this formula to one-half or one-quarter strength, because enclosed marijuana does not tolerate full-strength nutrient feedings well, and may exhibit the leaf drooping associated with a temporary shock to the system. Diluted solutions of 20 percent NPK are probably best administered twice a week, although some growers feed their plants at every watering. Marijuana plants grown outdoors aren’t so finicky, perhaps   because they have greater freedom for root growth and breathe naturally fresh air.

The science Behind the Food

Just as in people and animals, all of the nutrients listed here work together to maintain healthy growth and development, and every one of them can be critical. Plants may grow poorly, refuse to grow at all, or even die if deprived of any one of these nutrients, because some are symbiotic in their ability to be metabolized as food. If deprivation is acute, a plant may go into “nutrient lockout,” a phenomenon in which the lack of a single necessary element disables the plant’s ability to absorb some or all of the other nutritional elements. When deciding which fertilizer you want to use, pay attention to the ingredients you see on the side of the box. You don’t need to understand the exact bioscience behind the numerous chemical ingredients in each product, but if you know what elements to look for, you stand a better chance of providing the best munchies for your hungry plant.

-In the flowering stage, an increased amount of phosphorus is needed to promote the production of flowers and bud sites and to encourage maximum yield. Phosphorus by itself, or in a higher, unbalanced ratio of 10-30-10 (10 percent nitrogen, 30 percent phosphorous, and 10 percent potassium), is the most preferred feeding mix at this stage.

-Secondary foods that are required to achieve maximum growth and potency include calcium (Ca), sulfur (S), and magnesium (Mg). These nutritional elements ensure that plant photosynthesis will be at peak efficiency, inducing strong growth and rapid development.

-Trace minerals a plant needs include boron (B), copper (Cu), molybdenum (Mo), zinc (Zn), iron (Fe), and manganese (Mn). Only small amounts of these elements are needed, but they are essential parts of the formula for total health.

Health problems that your plants experience as a result of needing nutrients are easy to remedy with almost any off-the-shelf general-purpose plant food, but you must act quickly. Aside from the need to bring a plant back to verdant health, think in terms of lost growth; a healthy plant in mid-July is typically between 2 and 3 feet tall, and before harvest time in October or November it will be 5 feet tall or more. Even a mild case of plant malnutrition can subtract two reeks of potential growth, so it’s important to keep plants as healthy as they can possibly be throughout their growing cycle.

Want to know more about growing marijuana? Get a free guide about growing marijuana at this link here. Order some high quality marijuana seeds at this link here.



About Author

Robert Bergman is a master marijuana grower. Robert Bergman is the author of 'Marijuana Plant Care' and 'The Marijuana Grow Bible'.


  1. What kind of food and also fertilizer do you guys use from start to finish since they’re two separate things? I’d rele appreciate it. I understand you need 3 diff kinds for the 3 stages.

  2. I dunno about the miracle gro. That stuff is commercial crap for the masses that won’t produce the best results, u want the best then produce from a company that derives their plant foods especially for marijuana or better yet, produce from 100% organic sources for the best results overall. Also, I grow in dirt and my plants are dry within 3 to 4 days after the first week of watering, around 4 to 5 week they are sucking up water every 2 to 3 days

  3. When I compare this kind of information with how the tobacco plant is processed into a cigarette (sure, we can add one more toxic chemical, why not), you have to wonder why all smokers (of cigarettes) don’t just stand up, throw away their Marlboros, and head to Colorado, the state of Washington, or Oregon. Like right now. (Don’t keep reading. Go. Now.) (I mean, keep reading The Weed Blog, but start packing…)

  4. tomato miracle gro. use about 2 and a half big scoops per gallon at every feeding. it is nitrogen, potassium, manganese, all the main things u need,

  5. ammonia the same stuff u use to clean your house with. That is the key ingredient in marijuana fertilizer along with aglime “Limestone” “Chalk”. I get my other minerals from my Multi vitamins that I dissolve in the water or mix in the soil. potassium from the banana peels. also I let banana sit in water over night to allow the banana juice and potassium to extract from the banana into the water to actually water on my leaves and roots.

  6. Anhydrous ammonia for the Nitrogen, aglime “Limestone” for the calcium, if your doing soil then crush up 20 complete multi vitamins in your soil, use lava rock as drainage instead of gravel, mix sliced and chopped banana peels in your soil, crab, lobster, fish skeleton, manure. use a higher ph level water around like 7 or 8 so that your crop is non acidic. also add to your water fresh squeezed fruit juices, adds a little flavor and smell to your bud along with a little fertilization. use uvb and uvc fluorescents. Lollipop, crop, top, scrog. to get your best yield. use more nutrients then some people tell you to get more potent buds and higher yields.

  7. I’d maybe clean that article up a little. Anyone growing in soil knows there is no possible way that you are watering your plants that often, nevermind fertilizing so often. Indoor pails with a 50% humidity can go 7-10 days easy without being watered so if you are real lucky you are going to get 2 feedings a month, and even at that rate cannabis doesn’t need more than a good, 4,3,5 organic

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