Too Much Fertilizer On Plants: Managing Fertilizer Burn In Gardens


There are many different types of chemical burns on plants. Some of them are not harmful to your garden, but some may cause damage or even death. There are two main types of chemical burns on plants:

1) Chemical Burns From Chemicals

Chemical burns from chemicals are caused when chemicals get into the soil, water, air or other living things around your plant. They may be from pesticides (which include herbicides), fertilizers, insecticides and fungicides. All these kinds of chemicals have been used for years without any problems.

However, there have been cases where they were found to cause severe damage to plants.

The most common type of chemical burns on plants is from herbicide sprays. These chemicals are sprayed onto the ground near your plant to kill weeds. Sometimes they may also be applied directly to the leaves and stems of your plants.

Spraying is usually done with a spray gun, which releases tiny droplets of poison over large areas. If you live in an area where spraying is allowed, then it’s very likely that you’ll see herbicide sprayed all over the place!

Insecticide and fungicide burns are not too common. Fungicides are normally only applied to crops that are more prone to fungal diseases or after a fungal disease has already occurred. In some parts of the world, the governments require farmers to spray insecticides to prevent serious insect infestations.

2) Chemical Burns From Fertilizers

Fertilizer burn may sound strange to you since plants need nutrients! However, too much of a good thing isn’t always good! Most chemical burns on plants are caused by overfeeding fertilizers to the soil or the plant’s leaves.

This is especially true with nitrogen. While excess nitrogen can cause a lot of damage, most chemical burns come from too much potassium and phosphorus. Fortunately, chemical burn from most fertilizers can be easily solved by applying less fertilizer next time around.

Chemical burns from other types of chemicals are not as easy to detect. For example, liquid potash can cause chemical burns when it comes in contact with skin or land on the plant itself. Sulfur is another common culprit.

Sulfur may not always be as toxic, but it can still cause damage to plants if they come in contact with it.

Another serious problem with fertilizer burn is the delay in effect. Most chemical burns on plants occur within a week or two after the fertilizer is applied. However, some of the damage from other kinds of chemicals may only show up after several weeks or months.

Unfortunately, the damage has already been done by that time!

Too Much Fertilizer On Plants: Managing Fertilizer Burn In Gardens - Picture


It’s very easy to prevent many kinds of fertilizer burns on plants. The best way is to only apply the exact amount of fertilizer that your plants need. Too much of any kind of fertilizer will cause damage to your plants.

The easiest way to find out how much fertilizer your plants need is to get a soil test done by your local university. They will send you back a report detailing how much of each kind of nutrient is in the soil. From that, you’ll know exactly how much fertilizer to add.

The only problem with this method is that it can be very expensive (the test costs at least $15). However, some counties do provide free testing services. Just do a search online for “fertilizer soil test” along with the name of your county to find out more information.

If getting a soil test sounds like too much trouble, then here are some rough guidelines for how much fertilizer to use.

For compost, grass clippings, and other kinds of “organic” fertilizer, apply 1 to 2 inches of material. Spread it out over your entire garden and make sure that it’s incorporated into the top 6 to 8 inches of soil.

If you’re using chemical fertilizer, then apply 1 pound of nitrogen per 100 square feet, 0.5 pound of phosphorus per 100 square feet, and 0.25 pound of potassium per 100 square feet.

Spread these materials out evenly as well.

It may take a little experimentation to get the fertilizer amounts right. However, you’ll soon get the hang of it and your plants will thrive as a result.

Too Much Fertilizer On Plants: Managing Fertilizer Burn In Gardens - Image


There are many other potential causes of plant health problems. In fact, there are over 180 known chemicals that can cause plant damage! However, the ones mentioned above are the most common ones.

If you’re having plant health problems and the plants are not that old (less than 1 or 2 years), then it’s probably due to one of the culprits mentioned above. Otherwise, there may be something else wrong, such as the plant growing environment.

Other potential causes of plant problems include lack of water, lack of sunlight, infestation of pests and diseases, and so on.


Chemical burns on plants can be very serious problems. While it may not kill your plant right away, the chemicals may cause lasting damage to the plant’s health and fertility. Damage to the leaves, for example, can cause a reduction in photosynthesis and lower water uptake.

Other kinds of chemical burns can kill the entire plant or prevent new growth altogether.

The best way to prevent these kinds of burns is to be careful when applying any kind of chemical, whether it’s a herbicide, pesticide, or fertilizer. Do your research first and try an organic alternative if possible. If not, be very careful when applying the substance to your plants.

Always follow the instructions that come with the chemical.

Finally, be aware of any spills or leaks. No matter how careful you are, mistakes can happen. So if you do experience a leak or spill, clean it up right away.

If you have pets or children, make extra sure that they stay away from the area until you know that it’s safe.

And that’s it for this episode. As always, thanks for watching and stay smart!

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tags: chemicals , chemical burns , plant health , problems , solutions

Sources & references used in this article:

Soil test interpretations and fertilizer management for lawns, turf, gardens, and landscape plants by CJ Rosen, PM Bierman, R Eliason – 2008 –

Nutrient management for blueberries in Oregon by JM Hart, B Strik, L White, W Yang – 2006 –

Soil, fertilizer, and plant silicon research in Japan by BG Hallock, EB Adams – 1979 – Pullman, Washington: Washington …

Role of nitrogen for plant growth and development: A review by JF Ma, E Takahashi – 2002 –

Interaction of competition and management in regulating composition and sustainability of native pasture by SJ Leghari, NA Wahocho, GM Laghari… – Advances in …, 2016 –

Environmental Horticulture: Guide to Nutrient Management by DL Garden, TP Bolger – … in pastures’.(Eds PG Tow, A …, 2001 –

î î for lawns and gardens by D Relf – 2009 –

Nitrogen in crop production: An account of global flows by W Conservatwn –



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