What Is Nutrient Burn? Everything to Know

Is there anything plants can’t do? They clean the air, brighten our homes and yards, provide habitats for wildlife and serve as a vital food source in the ecosystem. It’s no wonder we try to give them the best care we can, like the right amount of light and water. They need nutrients, too—  that’s where things get tricky. It’s possible to love them a little too much, especially when it comes to feeding them.

“All too often, people think fertilizer is a requirement for growing plants,” says Spencer Campbell, manager of the Plant Clinic at the Morton Arboretum in Lisle, Illinois. “Not necessarily.” Excessive nutrients from fertilizer treatments can cause nutrient burn, also called fertilizer burn, and this unsightly damage means your beloved plant is stressed.

Below, we talk to Campbell and Lisa Eldred Steinkopf, aka the Houseplant Guru, to help you identify and prevent nutrient burn.

What Is Nutrient Burn?

“Nutrient burn is an excess build-up of nutrients such as nitrogen, phosphorous or potassium in a plant,” Eldred Steinkopf says. Plants use these and other nutrients for root, stem, leaf and seed development and to support the plant’s vascular system, which moves the nutrients to where they need to go. But when plants get too many nutrients, Campbell says it results in malformed growth.

In a way, nutrient burn is plant self-preservation. “It’s trying to push the nutrients as far away from the plant as possible, to the edges of the leaves,” Campbell says. That’s why you often see signs of nutrient burn on a plant’s leaf tips.

What Are the Signs of Nutrient Burn?

Stressed-out plants can’t tell you they’re getting too much food, so keep an eye out for these visual signs of over-fertilizing:

• Bending or curling leaf tips.
• Tips that turn yellow or brown.
• Leaves that turn a really deep green or other color.
• Any growth that’s out of the expected pattern for that plant.

Yellow leaves can also signal other plant problems, like overwatering, so you might have to play detective. Look for additional signs to confirm you have nutrient burn and not something else.

What Plants Are Most Affected by Nutrient Burn?

All plants need nutrients for growth and development, so all plants are at risk for nutrient burn. “Thin-leaved plants are more likely to burn than thicker-leaved plants,” Eldred Steinkopf says, pointing to ferns, fittonias and calatheas as particularly susceptible. “But any plant can be affected if the salt build-up from fertilizers becomes too high.”

That goes for every plant in your home and yard, not just houseplants. If a plant shows a need for extra nutrients for leaf or root development, for example, fertilizer can be appropriate, but “a prescription without a diagnosis is malpractice,” Campbell says.

How Can I Prevent Nutrient Burn?

To avoid nutrient burn, avoid over-fertilizing. Both experts can’t stress this enough. Follow the fertilizer’s instructions and “be conservative and judicious when you’re applying it,” Campbell says. “I never use the full strength called for on my indoor plants. I usually use half to three-quarter strength,” Eldred Steinkopf says.

Choose the appropriate fertilizer for the plant type, and be observant. Roses need fertilizer at certain times in their development to help build strong roots; other plants prefer different timing. Or, maybe a tree in your yard has leaves that aren’t fully emerging, which is a sign of stress. Knowing your plants will help you determine if and when fertilizing is appropriate and how much. “Start with a little bit, and see if it perks up in response,” Campbell says.

Choose well-draining soil when planting, and check your current pots for proper drainage. Proper watering can help move nutrients through. “If you exclusively bottom-water your plants, they should be flushed at least once a month to prevent fertilizer build-up,” Eldred Steinkopf says.

Can Nutrient Burn Be Reversed?

No. But you can salvage the plant if it’s not too far gone. “If you see burn on your plants, cut those parts off — they are brown and not photosynthesizing anymore — and flush the soil multiple times with water to wash out the remaining excess nutrients,” Eldred Steinkopf says. “Repotting in fresh soil is also a good idea.”

Then, it’s a waiting game. “Never underestimate a plant’s willingness to survive,” Campbell says, but sometimes you can try everything, and it just won’t work. “Time does heal most wounds, but sometimes the best thing to do is start over,” Campbell says.

About the Experts

• Spencer Campbell is the plant clinic manager at the Morton Arboretum in Lisle, Illinois, where he and Plant Clinic staff answer more than 10,000 plant questions each year from the public. Campbell got his start in environmental advocacy before turning to plant care and education. He’s been at the Morton Arboretum for ten years.
• Lisa Eldred Steinkopf is The Houseplant Guru and author of multiple books on houseplant care. She is regularly featured in publications across the web and in speaking engagements, where she shares her love and knowledge of all things houseplant.