Too Much Humic Acid on Lawn? Here’s What to Do

When you have too much humic acid on your lawn, you may be wondering when the negative effects will set in. Will the “acid” eat your grass? Will it build up over time and lead to root decomposition? No matter what your worries are, this article will help you decide on a plan of action and minimize the effects of adding too much humic acid to your lawn.

Too Much Humic Acid on Lawn

If you add “too much” humic acid to your lawn, you shouldn’t see any adverse effects unless the granular humic acid is so thick that it’s blocking out all light and air. Beyond watering your lawn as usual, there’s nothing else you need to do if you add too much humic acid to your lawn. Though the humic acid won’t be utilized to its full potential, it shouldn’t cause any harm to your lawn, trees, or ornamentals.

How Too Much Humic Acid Will Affect Your Lawn

Too much humic acid will not affect your lawn directly in any notable way. It will not make your soil too soft, it will not rot the roots of your grass, and it will not cause any sort of discoloration. Too much humic acid on a lawn isn’t a problem for the grass itself, especially if you prefer to stay away from commercial pesticides and herbicides.

However, if you do frequently apply many fungicide, pesticide, or herbicide products to your soil that need to remain in the soil to work you may find yourself at a loss when they suddenly lose effectiveness. Humic acid, in even moderate quantities, can greatly reduce the effectiveness and availability of these pesticides, herbicides, and fungicides in the soil and roots of plants.

Can You Put Too Much Humic Acid on a Lawn?

No, you can’t put too much humic acid on your lawn under normal circumstances. To put too much humic acid on your lawn, you’d need a wagon full of the stuff or a 50 lb sack at a minimum. Then it would all need to be piled in as small an area as possible with only a sprinkle of water applied. Then the granular humic acid would smother the underlying grass. The humic acid itself, however, wouldn’t cause any notable harm, the lack of light and air would.

How to Know How Much Humic Acid to Use on Your Lawn

Now that you know the answer to “Can you put too much humic acid on your lawn?” is a strong, “No,” you may want to know why there is an ideal level or how to determine the ideal level for your lawn.

Different forms of humic acid will advise you with different application rates. For example, a liquid product may say you need to use 12 oz, diluted to 1 gallon of water for every ounce of product, spread out over 1000 square feet. Granular humic acid may say you need to broadcast 10 pounds over that same 1000 square feet of lawn once or twice a year.

The strength of these two products, ounce for ounce, is very similar in this example. Why would the directions be so different? The truth is, an initial application of humic acid should be heavy, usually at about 4 to 5 lbs of granular humic acid per 1000 square feet. Then, in the following year, only 2 to 3 pounds should be needed for this same amount of lawn.

Liquid humic acid products should always be used according to the directions on the bottle as they may have more varied concentrations in some cases. The liquid concentrate in the above example had the same strength as that of the granular humic acid.

While the directions on some packaging may say you should use more granular humic acid, you may not need to want to. Humic acid takes time to work and adding more all at once won’t speed up this process. However, if you have the extra money to spend, there is no harm in using more granular humic acid on your lawn but don’t expect more of an effect.

What to Do When You Put Too Much Humic Acid on Your Lawn

If you have applied a solution of liquid humic acid that wasn’t diluted properly onto your lawn, you can dilute it after the fact by applying more water. No matter what the concentration of humic acid solution should have been, 15 to 20 minutes of even watering should suffice. This is the same procedure you should follow if you have broadcast too much granular humic acid on your lawn.

If you have spilled a large amount of humic acid over a given spot and wish to save some, you can do so as long as the granular humic acid is still dry. Simply scoop or sweep up the humic acid and return it to its container. Any remaining granular humic acid should be spread out and watered over to help dilute it.

As mentioned above, humic acid use, even in the suggested amounts, can decrease the effectiveness of many pesticides, herbicides, and fungicides. Keep an eye on any conditions you treat with these products to ensure that there have been no outbreaks. If there have been, you may need to carefully apply more of these other products. To do so safely, you may need to contact the manufacturer for guidance.