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Understanding Nutrient Burn

Nutrient Burn

Even novice growers usually understand that marijuana plants need plenty of nutrients to grow and thrive. What some fail to recognize is that applying nutrients in heavy concentrations can be just as damaging to their plants as under-feeding them. As a result, nutrient burn is one of the most common problems faced by novice growers. Read on to learn about the symptoms and causes of nutrient burn, how to prevent it, and how to treat it if the plants are already suffering.

What Is Nutrient Burn?

Sometimes referred to colloquially among experienced growers as “Nute Burn,” nutrient burn occurs when plants are grown in soil or hydroponic solutions that contain excessive concentrations of certain macro- or micronutrients. High concentrations of some nutrients can inhibit the intake of other nutrients, and an overabundance of any nutrient can negatively affect leaf health.

Symptoms of Nutrient Burn

The symptoms of nutrient burn vary slightly depending on which nutrients are overconcentrated in the soil or hydroponic solution, but they almost always affect the plants’ leaves first. They can cause brown spots, yellow or brown burnt-looking leaf tips or edges, and curling under of the leaves.

Paying close attention to the plant’s leaf symptoms can give growers an idea of which nutrients are overconcentrated. Excessive nitrogen, for example, will cause the plants’ leaves to curl downward. Excessive potassium will cause the leaves to form brown spots near their edges.

Some types of nutrient burn will affect new growth near the tops of the plants first, while others will damage the larger, established leaves near the bottom. However, if left unaddressed, the problem will almost always spread to all areas of the plant. Since leaf damage inhibits photosynthesis, growers will eventually notice their plants’ growth slowing down, or even grinding to a halt entirely. Take action before that happens.

Causes of Nutrient Burn

The underlying cause of nutrient burn is always the same. The plants are getting too much of at least one type of nutrient. Growers may be adding too much fertilizer or plant food, or they may be using a product that isn’t formulated specifically for marijuana plants.

Even using products intended for other stages of growth can cause nutrient burn in sensitive plants, so check the labels carefully before purchasing new products. Only use fertilizers and plant foods designed for the vegetative stage when the plants are in veg, and only use products designed for the flowering stage while they are in bud.

Don’t assume that following the manufacturers’ recommendations will always be enough to prevent nutrient burn on your indoor weed plants or crop of outdoor feminized seeds. Other environmental conditions such as pH, EC, and TDS levels can all affect how well marijuana plants can absorb certain nutrients. It’s always best to keep an eye out for signs of Nute Burn, even when growers are using products formulated for marijuana in exactly the recommended concentrations.

How to Fix Nutrient Burn

Recognizing the symptoms of nutrient burn is an important first step toward fixing the problem, but the plants won’t be able to resume a healthy growth pattern until growers restore balance to their gardens or hydroponic systems. This requires a slightly different solution depending on whether they grow in soil or a hydroponic system.

Fixing Nute Burn in Soil-Based Container Grows

The easiest way to fix nute burn in a soil-based or coco coir-based container grow is to flush the existing nutrients from the grow media and start over. To flush soil or coco coir, use pH-balanced water at the first sign of nutrient burn.

Water the plants until it starts coming out the drainage holes at the bottom of the container, then wait a few minutes and do it again. This should remove all the nutrients from the soil or coco coir, giving growers a fresh start. When applying new nutrient mixes, start slow and consider using half the concentration recommended by the manufacturer for the first feeding to avoid further issues.

Fixing Nute Burn in Outdoor Gardens

Outdoor growers who plant directly into the ground can give their plants extra water, but they should avoid waterlogging the soil in the garden. Instead, abstain from feeding the plants to give them time to use up the extra nutrients. If the older leaves have sustained substantial damage, they probably won’t recover. However, the plants should start producing new, healthy leaves within a week.

Fixing Nute Burn in Hydroponic Systems

Hydroponic growers can also flush their systems using pure, pH-balanced water. Just add plenty of extra water to thin out the nutrients and wait a while to feed the plants again. Hydroponic growers should also dilute their nutrient mixes to ensure that the plants don’t get burned again. This should produce almost instant results, in that the symptoms of nutrient burn should stop expanding to new areas of the plants.

Balancing nutrients in a hydroponic system is trickier than feeding plants grown in soil or soilless media like coco coir, especially if growers are cultivating multiple strains of marijuanna seeds for sale at Each strain responds to nutrient levels in the hydroponic solution a little differently. Some plants may even experience nutrient deficiencies while others are exhibiting symptoms of nutrient burn.

To complicate matters further for indoor growers, humidity and temperature can also affect how quickly plants use up water, which alters the concentration of the nutrient solution. If altering the nutrient mix seems to work for one plant, but causes a deficiency in another plant, growers may want to reconsider which strains they’re cultivating or expand their grows to contain two separate hydroponic systems.

Preventing Nutrient Burn

As with most things in life, the best cure for nutrient burn is prevention. To prevent nutrient burns, don’t go overboard when feeding plants. It’s better to start slow when applying liquid fertilizers and plant foods than it is to create an overconcentration of nutrients in the soil or hydroponic solution.

Hydroponic growers should also invest in a tool called a TDS meter. TDS meters measure total dissolved solids in the nutrient solution, allowing growers to measure changes in nutrient levels with a much greater degree of accuracy. Check the TDS level before and after making any change to the nutrient solution.

Soil-based growers can also use TDS meters to measure the concentrations of their liquid plant foods. Container growers can also measure the TDS levels in the water draining from their containers after flushing their plants. Most experienced soil-based growers don’t use these tools extensively, but they’re inexpensive and they can be very useful for those who are new to growing cannabis.

Nutrient Burns During the Flowering Stage

Marijuana plants are more susceptible to damage when they are in the flowering stage, and that includes nutrient burns. Once they start to flower, the green crack sativa or g13 indica plants will be devoting almost all of their energy to producing heavy, dense buds, so they won’t be able to repair damage as efficiently. It’s very important for growers to pay careful attention to their plants during this stage, especially as harvest time approaches. Treat nutrient burns immediately by flushing the soil or hydroponic system.

Pre-Harvest Flushing

No matter what media they use to grow their crops, growers should flush any remaining nutrients from their systems one to two weeks before they plan to harvest. This allows the plants to use up any remaining nutrients, ensuring that the final product will look, taste, and smell great. If the plants receive nutrients all the way up until harvest, the dried buds may end up with an unpleasant chemical smell or taste, so pre-harvest flushing should be considered a necessity, not an optional activity.

Each grow medium requires a slightly different flushing time frame. Soil needs to be flushed two weeks before harvest, while soilless media like coco coir and Rockwool should be flushed just one week before harvest. Hydroponic growers can wait until a few days before the end of the season.

The only growers who should not flush their systems are those who use naturally amended organic soil. Plants grown in organic soil rely on a complex web of soil microorganisms to grow and thrive, and flushing the nutrients from the system can also wind up flushing out these beneficial microbes, effectively sterilizing the soil and rendering it useless for the next season’s grow. Plus, most organic growers water their 3 kings kush or strawberry cough auto plants with pure water, so there is less likelihood of nutrient buildup.

The Bottom Line

Nutrient burn is a serious problem that plagues many novice growers. If left unchecked, it can stunt growth and cause substantially reduced yields. The best way to deal with nutrient burn is to avoid it by erring on the side of caution when applying new plant foods, fertilizers, or nutrient mixes. Starting with easy grow pot seeds can give you some more room for error, but no seed is strong enough to endure vast over-feeding of certain nutrients.

Growers who are already noticing symptoms of Nute Burn don’t need to panic. Almost everyone deals with this problem at some point in his or her cannabis cultivation career. Flushing the system will remove the excess nutrients from the soil, leaving growers with a blank slate. Reapply a more balanced mix of nutrients formulated for the plants’ current growth stage, then be more careful about overconcentrating plant foods and fertilizers in the future. We want you to achieve the highest yield possible for your newly purchased i49 seeds, so please use this guide along with the other articles within our comprehensive grow guide, found here.