If you’ve ever poured all your efforts into growing cannabis plants only to discover them with drooping, brown, curled-up leaves, you know what devastation nute burn can cause.
No one wants to destroy an entire crop thanks to a pesky, preventable illness, especially not if it’s almost at a point of harvest. We’re here to share all the ins and outs of nutrient burn, including how to treat and prevent it so that you’ll never need to worry about losing out on a harvest again.
What is nute burn?
Nute burn, otherwise known as the “Novices lament,” is damage endured by plants due to an overabundance of nutrients. In essence, it’s harm caused by overfertilization. Cannabis can’t handle being overfed and, in turn, gets sick.
Any excess in nutes, whether it be caused by human-induced overfeeding or environmental factors such as soils that are too rich in plant food, will lead to nutrient burn.
Let’s take a look at some of the common causes of nutrient burn in cannabis.
- Drying out plants too much. If you’re letting your plants dry out for too long between watering, you’ll need to remember to feed them in more limited amounts. Less liquid but the same nutrients will almost definitely lead to future headaches. Always be sure that your nute to water ratios remain constant.
- Overuse of bloom boosters. Bloom boosters consist of potassium (K) and phosphorus (P), both of which can be detrimental to your plant’s health if overused. Always use these fertilizers as directed to steer clear of potential damage.
- Nutrient-abundant soils. If your ganja is cultivated in soils that contain high levels of manure or other added compost, they may be too rich to accommodate your plants.
- Overwatering. Plants cannot function to their full potential or access oxygen if they aren’t allowed to dry out a little bit.
What’s the effect of nutrient burn on cannabis plants?
Both leaves and roots are injured as a result of nute burn, but the blades suffer the most. When brown and scorched, foliage is unable to absorb light efficiently and can’t photosynthesize. This vital chemical process loss means light can’t be turned into energy, and the whole plant suffers.
Nute burn in the vegetative phase
If caught early enough, cannabis nutrient burn can be fixed during the vegetative phase. You’ll simply need to remove all the affected blades. Should your weed experience crop-wide yellowing, wilting, and leaf curling overnight, the issue has progressed too quickly, and it’ll be best to remove your herbs and start again.
Nutrient burn during flowering
It’s not only foliage that is affected by nute burn. Buds can get sick too. It’s important to remember that marijuana uses nutrients differently when it flowers as opposed to during vegetative growth.
There is almost no need for nitrogen (N) during flowering and a much greater need for calcium (Ca) and magnesium (Mg). By this logic, if you feed too much nitrogen, you’ll end up with weed burn.
Flowering plants are much more susceptible to severe damage, and nutrient burn recovery takes much longer. The closer your herbs are to harvest, the more difficult it will be for them to regenerate as all their energy will go towards making buds.
Micro-nutrients are needed in this stage but NOT IN EXCESS. If flowers are affected, you’ll need to remove the entire florette right down to the calyx.
The ways to spot nutrient burn in its early stages
If you catch cannabis nute burn early enough, you’ll be able to cure it before it takes over your plants and leaves you at a point of no return.
- Very deep green leaves with fluorescent tips. One of the first signs of weed nutrient burn is a dark green leaf center with yellowing points.
- Bent leaf tips. After turning yellow, tips may turn brown and begin to bend to a 90-degree angle.
- Red, magenta, or purple stems. Stems are often one of the biggest indicators of cannabis nute burn. Once you notice them darkening and turning red/purple, you know you’ve got a problem on your hands.
The best ways to treat nute burn
Are you wondering how to fix nutrient burn? Fortunately, if caught early enough, you have a wide array of options to help your plants heal and return to their full glory. Crops with more advanced cases may be a bit trickier when it comes to nutrient burn recovery.
Flush your plants
If you use a hand watering system (soil/coco coir), you’ll want to heavily irrigate/flush your plants with plain, pH-tested water as soon as you notice signs of nute burn.
Remove affected areas
Cutting your losses is the best way to go when it comes to weed nutrient burn. You can’t reverse the effects once they’ve taken hold of your crops, and removing affected leaves or buds is usually the most effective way to promote recovery.
Use bottled nutrients
When using premixed nutrients, it’s vital to use high-quality products that are specifically designed for weed. You’ll also want to be sure that you’re using the right nutrients for your plant’s growth stage. The vegetative and flowering phases have differing nutritional needs, and if you use the wrong fertilizer at the wrong time, cannabis nute burn is almost guaranteed.
Alter feeding schedule
The best thing to do when you start growing cannabis is to develop a feeding schedule, so you always know what fertilizer has been given to who and when. This way, you can alter things as and when your herbs need it.
A tool that's proved useful in monitoring the nutrient needs of weed is an EC monitor. By using one of these, you can measure and adjust the concentration of the fertilizer you give according to your plant’s needs.
Fixing nutrient burn in a hydroponics environment
In a hydroponics system, it’ll be best to add plain, pH-tested water to your plants to dilute the nutes. The alternative in cases of severe nutrient burn is to empty reservoirs, change the water completely, and start over.
It’s important to note that individual strains grown in hydro systems can handle different amounts of added nutrients. Adding 10% new water at a time until the weed burn stops will usually do the trick.
When reintroducing marijuana nutrients, it’s advised to start off with half of the recommended dose and slowly work your way up. If you notice that your shrub’s leaves are yellowing, you know you’ve gone too far and need to add less.
Preventing nute burn in the future
Prevention is always better than cure. If you’ve been left devastated by the effects of nute burn, chances are you’ll want to make 100% sure it never happens again. You can take a few basic precautions to avoid cannabis nute burn and keep your pot both healthy and happy.
Monitor your nutrient ratios
Ensure nutrient proportions are correct. Each strain requires a different amount of nutes, so you'll have to do your research on the variants you grow to be sure you don't over or underfeed them.
You'll also need to ensure run-off is similar to soil and pH solution. If this isn't the case, you should add fewer nutrients and more water.
Grow in organic soil
Organic soils are free of additives, including composts and other fertilizers. This provides you with a blank canvas to start off with, and you won’t have the risk of the ground’s nutrients causing issues for your weed crops.
Nutrient burn or deficiency
It’s not uncommon for growers to mistake other cannabis deficiencies for nute burn. Below are some signs of things that may look similar to help you determine if you’ve got a nutrient burn or a deficiency on your hands.
- Nitrogen deficiency. Nitrogen deficiency is one of the more common cannabis problems. Symptoms are very similar to nute burn in that your leaf blades will exhibit yellow tips.
- Potassium deficiency. A lack of potassium throws out symptoms of yellow and brown spots on foliage instead of discolored tips.
- Magnesium deficiency. The ends of your weed will turn brown with a light-green to yellow color spreading inwards.
Prevention is better than cure when it comes to cannabis problems. If you know what to look for, you’ll be able to stop nutrient burn in weed before it gives you too much of a headache. If you do run into issues, it’s best to diagnose and treat them before they take over, leaving you cropless.
