QUESTION from a reader:
We sprayed our lawn with a solution of 1 cup ammonia to one gallon of water. We now have a burned lawn. Is there anything we can do to save the lawn ?
Garden Counselor ANSWER:
It is so frustrating to experience such a negative result after attempting to improve your lawn with a homemade remedy using common household ingredients.
Unfortunately, ammonia can be a rather potent substance when used on plants in its basic form, even when diluted. The degree to which your grass burned attests to this.
The following points will explain why this problem developed, and what steps might remedy it, in those cases where the damage is not permanent.
1. Suggested ratios for lawn treatments can be deceiving.
One cup of ammonia (8 ounces) in a gallon is slightly more than 6% nitrogen. Since homeowners often buy fertilizers with over 20% nitrogen, this seem to be in a safe ratio.
However, when commercial granular fertilizers have the same or higher percentage of ammoniacal nitrogen in their formula, this does not all release at once.
Also, the common water soluble liquid fertilizers that many people purchase would typically be diluted much more than what you used in your homemade formula.
So what happened? The high concentration of ammonia has acted as a desiccant. This means it causes a plant to lose all the moisture internally, thus the effect of the grass appearing burned, simply from being dried up.
2. What to do to correct the cause of a burned lawn?
Drench or deep soak the lawn with water repeatedly. Plan to do this at least 3 -5 times over a few days period. Don't water so heavily at one time that that it just runs off.
If the ground doesn't easily let the water soak in, break up the watering into many cycles to accomplish the good soaking.
This technique would not be over the course of several days, but over several hours or all in one day as you are able.
Water as long as possible, wait 30-60 minutes, water again, and keep repeating the process.
The intent is to flush the ammonia salts down below the root zone.
3. Hard packed soil doesn't allow easy water penetration.
This not only presents a new difficulty in trying to remedy the situation, it may have contributed to the problem by leaving the lawn in a moisture deprived state.
In this case, get a product from your nursery that helps soil penetration, like "Naiad" or "Water-In" or "Pentrex" or Grow More EZ-WET. It has the effect of making the water slippery, so it can slide through the soil easier. It actually has rather good residual assistance, not just a one time benefit.
These products usually come as a concentrate that you will mix and spray on the surface of the lawn, and then follow with a full watering cycle.
You may also find them in a Ready-to-Spray container that attaches to your hose and it automatically distributes the product in the correct proportion as you spray. This is very convenient, but gets quite expensive (compared to self-mixing from a concentrate) if your lawn area is overly large.
4. Apply agricultural gypsum.
Use a rate of 10 pounds per 100 square feet, if you want to try every means possible to help the grass recover in a burned lawn. Just spread it loosely over the area before one of the watering cycles. This helps to open up the soil structure, allowing water to move through more easily.
The gypsum has another benefit, with the ability to attract salt ions to itself and helps carry them down through the soil.
(Fertilizers are basically salt compounds, so this is quite helpful not only when you have grass that is burned, but also any lawn or garden area that has been heavily fertilized year after year and doesn’t get considerable rainfall to regularly leach the salts past the roots.)
An easier approach is the application of a liquid gypsum product. Keep in mind that the sooner you can apply it, the better your chances to counteract the burn effect, if the grass is still viable.
5. Will the burned lawn recover?
That depends on a few factors, such as the type of grass, how well established it is, and how healthy it was prior to this incident.
(If you are a reader whose grass has burned from applying another type of chemical, the active ingredient and strength of the mixture will impact the extent of the damage. I hope to add additional articles on various lawn and garden products, as well as homemade remedy problems, each time inquiries are made. So look at the Site Map to see what is currently available.)
When grass gets fertilizer burn, it is a waiting game. The best thing is to be patient and give it time to recover if it can.
Watch the grass for signs of new growth coming out by checking at the crown of the individual plant. Pull apart the dead blades of grass to view the inner core and look for signs of new plant tissue emerging.
It would likely be a yellow-green color, even whitish, as the green color will depend on the plant being able to start manufacturing chlorophyll.
This may take 2-3 weeks to occur, depending on the resources that the little grass plants have stored in their roots.
The climate conditions will also affect the time of recovery. Cooler weather is good for healing, but makes new growth a slower process. Extremely hot temperatures will further stress the burned lawn, and could aggravate the potential for a completely dead lawn.
6. More yard problems may arise as a consequence.
A healthy, lush lawn is an ecosystem. A burned lawn seriously messes with that lowly, but important environment. Soil is not exposed to sun, wind, and the erosion of traffic, when your lawn grass is growing properly. Take away the thick, plentiful grass blades and you take away the protection for the soil and all the soil organisms.
What does this mean? Most critically, the soil will dry out more quickly and may need watering more frequently than what you encountered when grass shaded the soil.
Not more water in total quantity, (in fact, probably less water until the grass matures again), but needing water more frequently and consistently.
Failure to attend to this development will cause the roots near the top of the soil to get hot and stop functioning, even to die off.
Soil organisms are responsible for converting nutrients in the soil to a form that is usable by the plants. When the soil gets hot and dry, these little critters start to disappear (they die or head to more pleasant diggin's).
If the area is not too large where the grass burned, it would be very helpful to apply a thin layer of compost or fine screened mulch to protect the soil, hold in moisture, and keep the natural system intact for optimum recovery.
7. Do NOT try to stimulate grass growth with fertilizer application.
Not soon, or for a few weeks after regrowth starts. A quick release of nutrients might hasten the appearance of some green color in your lawn, but the overall impact is to cause more stress to the grass.
A burned lawn should not be forced to shape up according to your demands! It would be the equivalent of how you would feel if someone gave you an energy drink, then forced you to run a race, while recovering from the flu.
The exception to this would be a granular, organic fertilizer that has only natural ingredients (feather meal, blood meal, etc) and no lawn chemicals added. These release slowly and allow the grass to take up nutrients at the pace they are needed.
Only apply these organic fertilizers after you see significant green growth appearing.
Editor’s Note: Be careful with any homemade remedy.
See the articles on Tonics for Lawns and Homemade Weed Killer to get more information and examples of how a homemade remedy and household recipes for grass treatment can dump on you a few unexpected surprises, and a burned lawn may not be the worst event.
These so-called natural methods might be helpful, but could also leave you ready to write a new question to the Garden Counselor for Lawn Care Advice!