You may have good intentions when fertilizing your lawn, but not laying down the proper amount can cause your grass a lot of stress.
Here are four ways over-fertilizing can harm your turf:
1. Unnaturally Quick Growth Can Lead to More Maintenance & Future Turf Trouble
In humans, overeating has both short-term and long-term effects: a sudden burst of energy followed by fatigue, bloating, a desire to maintain eating larger-sized meals, eventual weight-gain, etc. Similarly, your grass will react negatively to excessive fertilization.
This burst of nutrients will cause your grass to (initially) grow very quickly. If you give your turf too much of a boost, you risk allowing the structure of your grass blades to grow much faster than its root system below. This can create problems hydrating and supplying more nutrients to the grass, as a plant can only suck up as much water and minerals as its roots allow.
Plus, it also means you have to mow more! What a time suck. Excessive mowing comes with its own problems too, but mostly it means your lawn is more likely to accumulate thatch, or dead grass, that can’t break down before the next trim. These excess shavings can make your property look messy, become a hideaway for pests and breed fungal diseases.
2. Soluble Salts Linger Behind & Can Cause “Root Burn”
Over-fertilizing can cause detrimental damage to your turf’s root structure as well. Some fertilizers contain high levels of nitrogen, which if absorbed in large amounts can become harmful.
What mainly causes the dreaded “burn,” however, is an abundant accumulation of soluble salts. Other nutrients found in fertilizers may get absorbed, but this left behind salt buildup can gather to toxic levels. Just like wintertime de-icer’s can sap your grass and soil of moisture and cause yellow patches around your sidewalk edges, these salts can make it harder for your plants to retain or take in moisture and can lead to withering or death of your grass and plants.
These high concentrations of sodium can also harm or kill the microorganisms naturally found in your soil, which help to maintain a balanced ecosystem for your turf.
3. Excessive Organic Matter Often Leads to Poor Drainage & Rot or Disease
Organic fertilizers contain natural organic matter, which breaks down with the help of water and provides your soil with rich nutrients to promote healthy growth. But just like anything in life, it’s possible to have too much of a good thing— and piling your lawn with too much of the stuff can have negative effects.
This matter can only break down so quickly, and if concentrations are overwhelming, they can essentially suffocate your grass, making it hard for water to get to its roots— or perhaps even worse, soaking up too much moisture and making it hard for your lawn to naturally drain. Oversaturation can drown out your grass, or the long-lasting wetness can welcome mold or fungal disease.
4. Excessive Nutrients Can Throw Off the PH Balance of Your Soil
Too much fertilizer can mess with the PH balance of your soil, which is a measure of its acidity or alkalinity. If your soil’s PH is greater than 7.3, AKA too alkaline, nitrogen and phosphorus cannot dissolve— which are two crucially important macronutrients needed for healthy grass growth. If it’s too acidic, at say at 4.5 PH, excessive nutrients like aluminum, iron and manganese can become toxic and kill your grass.
A formal soil test can help you to determine what nutrients your turf is lacking and which it has enough of so you can choose the best mix for nourishing your unique property. Ask a fertilization expert to sample your soil and offer recommendations for the best fertilizer, and for suggested application ratios.
Already Guilty of Over-Fertilizing? How to Recover
Unfortunately, if you’ve already over-fertilized your lawn, there’s not much you can do except wait. Soil levels will eventually rebalance over time, but to speed things up, you ask a lawn care expert for help.
With a proper soil test, a fertilization team can help you determine the best way to recover, and how to properly fertilize next time around— making recommendations based on actual data, without guessing games.
For more insights on nourishing your turf, download our Ultimate Guide to Fertilization. It offers tips for choosing the right fertilizer, how to apply it correctly and other best practices to foster a green, lively lawn.