Definition - What does Fertilizer Burn mean?
Fertilizer burn is a phenomenon that occurs when a plant is over-fertilized and exposed to excessive amounts of nitrogen salts. When fertilizer burn occurs, the leaf edges or blades of grass will appear brown and dry, as if they have been burnt by a flame. In this case there is no actual burn, but the plant tissues will have desiccated due to osmotic stress, a dysfunction that occurs when the excess nitrogen salts in the fertilizer cause rapid changes in the way water moves across the cell membranes of the affected plant tissues.
Fertilizer burn is also known as leaf scorch.
MaximumYield explains Fertilizer Burn
Fertilizer burn can be observed when you see the ends or edges of a plant’s leaves or blades turning brown and dying. Some novice horticulturalists mistakenly think that this occurs when a plant is not getting enough water or nutrients, but in most cases it occurs due to a nutrient overload.
Excessive use of fertilizer or the wrong type of fertilizer is not the only cause of fertilizer burn. It is also caused by transplant shock, drought, soil compaction, and some other factors. In most cases if the plant is watered regularly and the horticulturalist has used fertilizer, the cause will be either overuse of fertilizer or soil compaction.
In some cases fertilizer burn is caused by over-fertilizing a plant living in harsh conditions. Though the horticulturalist's intentions are to bring the plant back to health, adding too much fertilizer too soon can shock the plant and cause fertilizer burn.
Fertilizer burn can be prevented by testing the pH level of the soil or other grow medium and then using the appropriate type and amount of fertilizer to avoid excess nitrogen salts. It can also be prevented by adding aerating materials such as coco coir, tree bark, sand, or vermiculite to aerate the soil and improve water penetration.
If fertilizer burn is identified in an indoor garden it may be treated by flushing the soil with water to rid it of fertilizer. Once the soil or growing medium has been properly flushed, the proper fertilizer or nutrients can be added.