One common problem that many indoor growers run into is the leaves of their plants browning, curling, and drying out around the edges. The most likely cause is nutrient burn – or “nute burn,” as it’s commonly referred to in the cannabis growing community.
There are some early warning signs that can alert growers to a buildup of nutrients in the plant prior to burning. Those warning signs include:
The first step in remedying nutrient burn is to say goodbye to the parts of the plant that have already been affected. Nutrient burn can’t be reversed, and any leaves or buds that have already yellowed or browned are never going to be green again. Snipping off any damaged leaves and buds will prevent parts of the plant that have already been injured or died from rotting and causing further headaches.
In a hydroponic environment, growers should dial back the concentration of their fertilizers. If using prepackaged mixtures, growers can over dilute their solution to a lower level than the manufacturer’s recommendation. Growers mixing nutrients by hand should employ an EC meter to ensure that their mixtures haven’t been accidentally over concentrated and that EC levels fall in line with what their previously nute-burned plants need.
What are the symptoms of nutrient burn?
Nutrient burn is essentially damage caused by over-fertilization. Plants need four things to grow and be healthy; light, air, water, and nutrients. Those nutrients include plenty of nitrogen, and smaller amounts of a wide variety of other types like potassium, calcium, and more.
In a soil-based growing environment, flushing out the excess nutrients means heavy irrigation with pH-balanced water. Growers can simply heavily water their plants, allow the water to run off through the potters, and then repeat until the runoff measures in a healthy range with a total dissolved solids meter.
Symptoms of advanced nutrient burn include:
Nutrient Burn – How to Spot Overfertilization and Nip “Nute Burn” in the Bud
Spotting And Resolving Nutrient Burn In Your Indoor Growing Operation.
The yellow tips will eventually turn rusty brown and crispy. If you do not correct the problem, you may also notice the burn slowly spreading from the tips to the whole leaf. At this point, if you haven’t done so already, you should immediately treat your plant (directions below) before there’s more damage.
As nutrient burn progresses, the tips start getting bronze, crispy, curled and sometimes twisted. Although you can stop nutrient burn from getting worse, the burnt appearance won’t go away on the leaves that were already affected.
In general, plants use overall higher levels of nutrients as they get more light. Therefore plants in relatively low light conditions can get nutrient burn at lower levels of nutrient than the same plant would under bigger grow lights.
If you are using bottled nutrients – Most people who get nute burn are feeding their plants extra nutrients in the water. First off, make sure you are using a quality set of nutrients that has been specifically designed for cannabis plants. Any nutrient system designed for plants like a tomato will also work in a pinch. Also make sure you are feeding nutrients for the right growth stage – for example, all cannabis nutrient systems have you feed different nutrients for the vegetative and flowering stage. If you are feeding the wrong type of nutrients for the stage your plant is in, that is an easy way to give your plants lots of nutrient problems including nutrient burn.
Quick Summary: Nutrient burn or fertilizer burn is one of the most common beginner cannabis growing problems. The yellow or brown leaf tips are caused by too-high levels of nutrients at the roots, which disrupts the flow of water through the plant and causes the symptom of burnt tips on leaves.
Nutrient burn affects the tips of marijuana leaves. You may just see it on one or two leaves, or it can appear all over the plant.
In hydro, it is very helpful to get a tool called a TDS meter to help you regulate the amount of nutrients in your water. A TDS meter will be able to tell you how much “stuff” is in the water, and whether the levels of nutrients are getting higher or lower each time you check. You can test your reservoir at any time to see if the levels of nutrients are rising, so you’ll be able to stop nutrient burn before it even affects your plants.
I have heard some growers say that a little nutrient burn is actually a good thing, because it means that you are giving your plant the highest level of nutrients it can use. A lot of growers have the mistaken idea that nutrients are somehow “food” for your cannabis plants, and so more food = more energy = bigger yields.
To find out more about using a TDS meter to measure nutrients in your water, check out our article: PPM: What It Is and How To Track It.
Nutrient burn causes the tips of cannabis leaves to turn yellow or brown. The burnt tips are the result of too-high levels of nutrients. Learn how to fix it!