House Grail is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Should I Add Zinc To My Soil? Signs, Symptoms, & FAQ

tomato plant in a greenhouse

If you are a beginner gardener, it might be challenging to keep up with all the maintenance needs of your plants, especially if you’re unsure of everything you need to do. You should provide your plant with adequate lighting, watering, and the proper soil.

However, choosing suitable soil for your plant can be tricky, as it needs to have specific trace elements that allow your plant to thrive. One of those trace elements is zinc, which plays a vital role in plant development.

If you’re wondering if you should add zinc to your soil and what amount you need to add, check out the rest of the article.

We’ll provide you with all the details about the connection between zinc and plants.

garden flower divider

Do Plants Need Zinc In Their Soil?

Plants need various nutrients they absorb from their soil in order to grow. While some of the most common ones are nitrogen, phosphorus, and potassium, plants also need zinc to thrive.

Zinc is one of the eight micronutrients crucial for the development of plants. Without them, the plant would be smaller and less healthy. Many enzymes and proteins contain zinc as it contributes to growth production.

It also helps plants to withstand harsh weather and creates chlorophyll. While most soils experience a zinc deficiency, it’s not uncommon for soils to have high zinc levels. If that happens, your plants could suffer from zinc toxicity.

tomato plant exposed in the sun
Photo Credit By: fotohunter, Shutterstock

What Amount of Zinc Should Your Soil Contain?

The regular amount of zinc in the soil should be between 10 and 300 parts per million, although it’s commonly around 50 parts per million. Before the plant roots can soak up zinc, it needs to be dissolved in water.

Zinc is connected with the soil pH, so it becomes less soluble if the soil pH increases. Zinc can also be less available for plants when the pH level drops, especially in coarse soils. Organic matter found in soil can also affect zinc levels and make them lower than usual.

garden flower divider

Zinc Deficiency

Zinc deficiency is one of the most widespread issues with zinc in the soil. Since zinc is immobile, the symptoms only occur in the new leaves, and they can vary from plant to plant. Typically, soil conditions have an important role in zinc deficiency.

Alkaline soils are not the best environments for zinc, and they can lack this nutrient. Sandy soils also have issues in terms of zinc because they are leachable, meaning they can’t hold enough zinc a plant needs to grow and thrive. If your soil has a high concentration of organic matter, that could also lead to zinc efficiency.

Another vital factor in zinc deficiency is the planting conditions. When planting crops and plants in cold, wet weather, the soil won’t be able to release enough zinc to your plants. It’s also not uncommon that soils with high amounts of other micronutrients like phosphorous prevent zinc from reaching the plant

potato crops
Photo Credit By: Ehrecke, Pixabay

Zinc Deficiency Symptoms

You need to know how to recognize zinc deficiency symptoms in your plants to treat the issue promptly.

There are several ways to do that, including:
  • Soil testing
  • Issue testing
  • Visual signs

Soil tests are less efficient than other methods as they will show the amount of zinc in the soil but not the accessibility of this nutrient to the crop. However, it’s easier to diagnose visual signs.

Without enough zinc, your plant will showcase an array of problems and signs like:

  • Brown spots on leaves
  • Stunted growth
  • Distorted leaves
  • Light green areas between new leaves and veins
  • Smaller leaves

Zinc deficiency symptoms are similar to deficiencies of other micronutrients, so sometimes, it’s hard to tell the difference, which is why you should perform a soil test. Still, the best way to determine zinc deficiency in your plants is to perform a tissue test that will show if a plant has zinc deficiency or not.

How To Avoid a Zinc Deficiency?

Environmental and soil conditions are the leading causes of zinc deficiency, making it easy to anticipate if you need to take any precautionary measures. You can incorporate zinc fertilizers or foliar sprays into your plant care to ensure your plants will get enough of this needed micronutrient.

When your plant has good access to all the required micronutrients, it will grow healthier and reach its full potential.

Zinc Toxicity In Plants

Another problem you can encounter is zinc toxicity, although it’s not as common as zinc deficiency. This problem is common when plants grow in acidic soils with an excess of magnesium

Zinc Toxicity Symptoms

It’s hard to detect zinc toxicity as the symptoms are less visual than in zinc deficiency. The most common symptom is dark green leaves, which can sometimes go unnoticed. Other signs include:

  • Curling of new leaves
  • Stunted growth
  • Dead leaf tips
  • Root blunt

How To Avoid Zinc Toxicity?

To avoid zinc toxicity, monitor the soil pH levels so they don’t drop too low. You can also use fertilizers with nitrogen to lower the amount of zinc in the soil. Remember to stray away from fertilizers that contain zinc, as that would make the problem even worse.

garden flower divider

Should You Add Zinc To Your Soil?

If your soil has regular zinc levels, there’s no need to add zinc to your soil, as it could lead to zinc toxicity. However, if zinc levels in your soil are low and there’s zinc deficiency, you should apply zinc to your soil through sprays and fertilizers.

The zinc levels vary from crop to crop, although they’re frequently similar. Below is a chart showing the amount of zinc certain crops need to thrive.

Plant Zinc sufficiency range (ppm)
Apple 20 to 50
Broccoli 20 to 80
Carrot 25 to 250
Pea 25 to 100
Potato 20 to 40
Strawberry 20 to 50
Blueberry 25 to 60
Grape 20 to 45
Cabbage 20 to 200

These are optimal amounts that can vary depending on the type of your soil and your location.

How Much Zinc Should You Add?

If you perform a soil test indicating a need for adding zinc, you should apply a small amount of fertilizer. Zinc fertilizers use three different compounds that vary in zinc content, effectiveness, and price.

Those sources of zinc can be:
  • Inorganic compounds
  • Synthetic chelates
  • Organic compounds

Inorganic compounds typically have higher levels of zinc than organic compounds and synthetic chelates, but it’s best to use a fertilizer with natural organic compounds. Some fertilizer manufacturers draw zinc from zinc metal, which could potentially be harmful.

Before buying a zinc fertilizer, ensure it comes from a reputable producer and it doesn’t contain harmful substances or high levels of zinc.

As there’s no strict formula about how much zinc you should add to your soil, first perform a soil test to determine the current amount of zinc in the soil. Once you know the zinc level in the soil, you’ll be able to figure out which fertilizer to use and how much of it you should apply to the soil.

Typically, applying between 1 and 3 pounds per acre should be just enough, but again, that can vary due to the soil and environmental factors. Plants need only small amounts to get all the needed benefits and enhance their production. Still, remember that zinc requirements vary in plants and that they will change based on the soil conditions and type of fertilizer you use.

garden flower divider

Final Words

Adding a bit of zinc to your soil can be crucial in making your crops healthy and strong. At the same time, adding zinc to soils with high zinc levels could lead to zinc toxicity which could harm your plants. Before you use zinc on your soil, verify that there’s an actual need and a deficiency of zinc to prevent possible problems that could occur.

Featured Photo Credit By: OlgaS. Helga, Shutterstock


Related posts

OUR categories

Project ideas

Hand & power tools