I put fertilizer on my lawn, and a few days later I had patches of dead grass! Will I have to replant, or will the grass come back? –Roger

Over fertilizing is one of the quickest ways to kill your lawn. From general discoloration to those telltale stripes from overlapping spreader rows, excessive or careless fertilizing can cause quite a bit of damage to lawn grasses.

About Fertilizer Burn in Grass

Chemical fertilizers are made up of mineral salts. When you over fertilize, the salts build up in the soil and cause a drying effect, which can result in the grass turning yellow or brown and. This process is called “fertilizer burn.”

Fertilizer burn isn’t always fatal, and it’s hard to predict whether or not your lawn will recover. It depends on the amount and type of fertilizer that was applied, the moisture available, and the overall health of the grass. A slightly yellow lawn is likely to recover, while crispy brown grass may not. Recovery of your lawn also depends on how quickly you intervene.

How To Treat Fertilizer Burn in Grass

If you have applied too much fertilizer to your lawn:

• Remove Fertilizer: If you’ve spilled granular fertilizer or can see it on the ground, grab a broom or wet/dry vac and get up as much as you can before it dissolves into the lawn.
• Apply Water: As soon as you notice a problem with fertilizer burn, drag out the sprinklers! Water helps to dilute and flush the mineral salts away from the roots of your lawn. On the first day, water until the ground can’t soak in any more. Then water every day for about the next week. Water in the morning to reduce the risk of fungal diseases.
• Wait and See: At this point, there’s nothing you can do except wait and see if your lawn will recover from fertilizer burn. Unless it’s early spring with plenty of planting time left, I’d wait until the next planting season rolls around (fall for cool-season grasses, spring for warm-season grasses) before replanting. Then overseed thin spots, and sow seed or sod in large dead areas. In the future, be sure to fertilize your lawn very carefully!

How To Prevent Fertilizer Burn in Grass

To keep fertilizer burn from being a problem in your lawn, consider:

• Use Organic Fertilizer: Use organic fertilizers and well composted amendments. Organic fertilizers must be broken down by soil microbes according to nature’s timeline, which significantly reduces the chances of burning your lawn.
• Follow Fertilizer Instructions: Always apply fertilizer exactly according to package instructions. Different fertilizers come in different strengths, and it’s important not to over apply them to your lawn.
• Reduce Lawn Stress: If the grass in your lawn is in poor condition, fertilize it very lightly to ease it back to health. Resist the urge to feed heavily, since weak grass is easily burned by chemical fertilizers. Don’t fertilize lawns that are severely stressed by drought, heat, or disease – it won’t be absorbed and can cause further damage.

Further Information

• Fertilizer 101
• Fertilizer Application (video)
• How To Identify the Cause of Brown Spots In Your Lawn
• When and How to Fertilize Centipede Grass
• Applying ‘Weed and Feed’ Products to St. Augustine Grass
• How To Keep Dogs From Damaging Your Lawn
• The Debate Over Organic vs. Chemical Fertilizers
• How to Winterize the Grass in Your Lawn

Tags: , burn, fertilizer, grass, lawn