Fertilizer Burn: Signs, Fixes, Why More Isn't Better

More is not better. Crispy leaf tips, curled leaves and a white crust on the soil usually mean a plant got more feed than it could use. The fix is plain water and time, and the habit that prevents it is simple: follow the chart dose, measure with real spoons, and never mix stronger than the chart says. Any fertilizer can burn plants when it is overused, ours included. We do not claim otherwise.

What Fertilizer Burn Looks Like

Burn can show within days of one heavy feed, or build up over weeks of feeding slightly too much. It often hits many leaves at once. Treat the signs below as clues, not proof, because each one has other causes too.

Tip and edge burn. Dry, brown, crispy tips and edges, sometimes with a yellow band first. Also check for thirst, wind and hot dry air.
Curling or clawing. Leaf tips hook down or edges curl, and leaves look stiff and very dark. Also check for heat and strong light.
Salt crust. A white crust on the soil, the pot rim or the drainage holes. Also check for hard water deposits.
Wilting in damp soil. A droopy plant while the soil is still wet. Also check for overwatering and root problems.

If your last change was a bigger scoop, another product or a shorter gap between feeds, suspect overfeeding. If nothing changed, check water, light and heat first. A pale plant is not always a hungry plant.

Why More Feed Hurts Instead of Helping

Most fertilizers are, or release, dissolved salts. Too much salt around the roots makes it harder for them to take in water. Salts also travel with the water to the leaf edges, where the water evaporates and the salt stays behind. That is the brown tip.

Growth is limited by whatever is scarcest: light, water, warmth or root space. Once a plant has enough of a nutrient, more does not speed it up, and too much of one can crowd out others. That is why overfeeding can look like a deficiency, and why doubling the scoop on a pale plant often makes things worse.

The Usual Causes

The wrong spoon. A tablespoon is three teaspoons, so reading tsp as tbsp triples the dose.
Heaped scoops and doubling up to make up a missed feed or fix a pale plant.
Stacking products. Each one adds to the load. Give each its own chart dose and raise none of them.
Feeding too often. Frequency counts as much as dose.
Poor drainage, hard tap water, and hot or dry rooms, which let salts build faster.
Foliar sprays, which put concentrated nutrient straight onto leaf tissue.

What to Do: How to Fix Fertilizer Burn, in Order

For a mild case, such as a few brown tips with no crust or wilting, skip one feed and drop back to the base dose. For anything more, work through this list.

Stop feeding. Skip the next feed, boosters included, and do not make it up later with a stronger mix. Stop foliar sprays too.
Find the cause. Check your last mix: the spoon, the scoop, how many products, how many days between feeds.
Flush with plain water. Run plenty of plain water through the soil to wash out built-up salts. In a pot, water slowly in a few passes until it drains freely, several potfuls if you can, then empty the saucer. In a bed, soak slowly and deeply instead of flooding.
Clear the crust. Scrape white crust off the surface. If it is thick, replace the top inch or so of mix.
Water normally from here. Let the top of the soil dry a little between waterings, because stressed roots need air, and ease off strong light and heat while the plant recovers.
Judge by new growth. Burnt tips stay brown. Trim them for looks if you like, but leave healthy leaf. Clean new leaves mean it is working, which can take a week or two. If new growth is damaged too, the cause may be something other than feed.
Restart low. Return to the chart's base dose, in the usual order: water, Microbes (our liquid soil inoculant), then powders. Step up only as the chart says.

A flush also washes out useful nutrients, so use it for signs of overfeeding, not as routine. If the roots look brown and mushy, or the plant keeps declining, repotting into fresh mix is the last resort. If you repot, add Microbes the same day and hold feeding until new growth shows.

Prevention: Let the Chart Set the Dose

The feeding chart sets the dose. Our feeding schedule page lets you pick your plant and see its schedule. Measure per gallon of water, with real spoons and level scoops, and never mix stronger than the chart says. Chart doses for Veg, Incredible Bulk and Kelp It Real:

Veg: 1/4 to 1/2 tbsp (3/4 to 1 1/2 tsp) per gallon. Vegetative growth through pre-flower. Needs Microbes.
Incredible Bulk: 1/4 tbsp (3/4 tsp) base dose per gallon. Last 4 to 6 weeks of flowering only.
Kelp It Real: 1/4 tsp per gallon. Any stage.

Read the unit. Incredible Bulk's base dose is 1/4 tbsp, which is 3/4 tsp, three times the Kelp It Real dose of 1/4 tsp. The Bulk range on the chart is wide, but the base dose is the only one to start from. A dose higher up that range is not a target, and it is not a rescue dose for a plant that looks hungry. Follow the chart for your plant and week, and ask us if you are unsure.

Habits that help:

Start at the base dose and move up only as the chart says. Start seedlings and fresh transplants at the low end, since young roots are sensitive to salts.
Change one thing at a time, and write down the date, product and dose.
Treat foliar sprays as the exception. Bloom's manufacturer spec says to spray it only for a phosphorus or potassium leaf deficiency and to watch for tip burn. Our Incredible Bulk documentation gives no foliar use, so keep it in the soil water.

Growing in pots makes salt buildup easier to cause, so our guide to raised beds and container growing is worth a read alongside this one.

Where Growganica Fits

No Growganica product treats burn. The fix is water and time, and none of our products is exempt. Low numbers on the bag are not a reason to double the scoop.

Veg and Bloom both need Microbes to work as designed. Mix water first, then Microbes, then the powder. If you switch from Veg to Bloom, stop Veg.
Incredible Bulk is the finisher, added on top of Bloom and never instead of it. Our documentation says using it through the whole flowering cycle is overkill and unbalanced, and on burn it says: stay within dose.
Kelp It Real is the pick for houseplants, not Incredible Bulk. It is dosed in teaspoons, so check the spoon.

Not sure about a dose? Ask us before you mix a stronger batch.

Frequently Asked Questions

How do I know if I overfed my plants?

Look for crispy brown leaf tips and edges, leaves that curl or claw, a white crust on the soil, or a droopy plant in damp soil. These usually follow a heavier feed than normal. Each sign has other causes too, so check what changed first: a bigger scoop, another product, or a shorter gap between feeds. If nothing changed, look at water, light and heat before you blame the feed.

Does a higher dose give better results?

No. A plant uses what it needs, and the rest can build up as salt around the roots. We do not recommend any dose above the chart, and we do not claim a stronger mix works better. A dose higher up Incredible Bulk's chart range is not a target, and it is not a rescue dose for a plant that looks hungry.

How do I fix fertilizer burn?

Stop feeding, flush with plain water, and wait for clean new growth. Burnt tissue does not turn green again, so judge recovery by the new leaves, which can take a week or two. Then restart at the chart's base dose. The full order of steps is in the What to do section above.