Contrary to what many new growers may think, giving your marijuana plants an enormous dose of nutrients is not going to help them be healthier. In fact, giving them too many nutrients will actually harm them, causing something called "nutrient burn," or shortened among marijuana growers as "nute burn."
If your plants are suffering from a nutrient burn, they will likely exhibit signs of yellowing and burnt tips on the leaves. The leaves may become crunchy and crispy and their edges will begin to curl. Depending on the type of nutrient that is causing the burn, the leaves may also have brown spots on the leaf's edges (which generally happens with potassium toxicities).
Not only can nutrient burn affect the overall health of your marijuana plants, it could also lead to a poor tasting final product. It might taste like chemicals, which, of course, is altogether undesirable in marijuana. Therefore, it is crucial to stop nutrient burn before it goes too far.
The marijuana flowering phase
When your marijuana plants have reached their flowering phase, they have also approached the most critical point in their lives because of how vulnerable they are during this time. If they are at all harmed while in their flowering period, the plants have no hope of recovering. If your marijuana plants are currently flowering, make sure you are dedicating extra time and effort to keep them safe and healthy.
How does a nutrient burn occur?
The most common cause of a nutrient burn is simply adding too many extra nutrients into the water solution you are feeding your plants. You should be sure to use only nutrients that are recommended for marijuana plants. You can double check this by asking if they work well for tomato plants, which have some common characteristics with marijuana plants.
You also need to remember that different phases of a marijuana plant's life cycle require different combinations of nutrients. The vegetative stage and flowering stage need different kinds of nutrients, so you need to adjust your feeding schedule accordingly. If these steps are followed, you can avoid nutrient burn from the beginning. If, however, your plants are already experiencing a nutrient burn, continue reading for ways to solve the problem. Check out this marijuana watering and nutrients schedule article to avoid any future problems.
How to fix a nutrient burn?
If your plants are growing in a soil or coco coir system and you are watering them by hand, you can flush out the entire system by using water that has been pH-balanced. This will "reset" the growing medium and will allow the roots to recover from the problem they were facing, and then can use up the extra nutrients that are in the soil. Give them time to do that before adding more nutrients. This should fix the nutrient burn problem (although damaged leaves won't ever recover, so look for new growths to see the healthy changes). Download my free marijuana grow bible and learn how to flush your soil or rockwool.
If you are growing your plants in a hydroponic system, you will need to add some pH-balanced water to dilute the amount of nutrients that are already there. Your next batch of "feed" should also include fewer nutrients. Proceed with caution, however, as hydroponic systems always require a more gradual change. You can consider purchasing a TDS meter to help regulate the nutrients that are in the water.
Symptoms of nutrient burn
New growth, upper growth damaged
Leaf edges burnt, browning
Leaf tips burnt
Leaves curled under
Slowed growth of plant