How to Use Copper Sulfate in Garden?

How to Use Copper Sulfate in Garden?

Copper sulfate is a chemical compound that contains copper and sulfur. It’s also known as “blue stone” because of its deep blue color. Copper sulfate can be used to kill weeds, algae, fungi, and pests in gardens without harmful side effects to the soil or nearby plants.

Copper sulfate has been used in gardening for many years. This chemical can be applied to plants to control various problems such as algae, fungi, and moss. Copper sulfate is also an effective weed killer when mixed with other chemicals or sprayed onto the soil where weeds grow.

Copper sulfate is also effective against pests such as aphids, whiteflies, spider mites, and scale insects. When used as a foliar spray, it can help to control these pests without harming beneficial insects. Copper sulfate can be purchased at most garden stores or online retailers.

How Does Copper Sulfate Affect Garden Plants?

There are many reasons why gardeners would like to know how does copper sulfate affects garden plants. Copper is a natural mineral that aids in the growth of healthy and beautiful vegetables, fruits, and flowers. Sulfate is a compound that helps copper become more available to plants. When these two are combined, they create an excellent fertilizer for gardens.

The application of copper sulfate in the garden can be done through foliar feeding or soil drenching. For foliar feeding, mix one tablespoon of copper sulfate with one gallon of water and spray on the leaves of the plants. Do this once a week until you see desired results.

For soil drenching, dissolve one pound of copper sulfate in five gallons of water and pour around the base of each plant. You will need to repeat this process every four to six weeks throughout the growing season.

How Does Copper Sulfate Affect Garden Plants?

Always follow the directions on the label when using copper sulfate in your garden. When handling this chemical, wear gloves and safety equipment, and avoid breathing in the dust or fumes. Keep children and pets away from areas where copper sulfate has been applied. Copper sulfate should not be used near water sources such as ponds or streams since it can harm aquatic life [1].

Acting as a Fertilizer

Copper shortages can also cause stunted development; plants in extremely mineral-deficient soils are more likely to die prematurely. Wilting of failing blooms, as well as lower fruit production, are all possible consequences of copper-poor soil.

In order to make sure that the copper sulfate is not too strong, try diluting it with water. Mix one tablespoon of copper sulfate per gallon of water before spraying your plants. Start by testing a small area on the plant first and wait 24 hours to see if there are any adverse effects such as leaf burning or stippling.

In soils with high levels of organic material, the application of too much copper can be toxic to plants and may cause them to die from root burn. In order to avoid this, only use a quarter teaspoon per plant for 3 weeks during the growing season if using it as a fertilizer. When used in soil that is already rich in trace minerals, adding more copper will have no effect on your garden’s growth rate.

Copper sulfate is a substance that can be used to cure and prevent copper deficiency. Annually, you should check the soil and apply copper sulfate as needed in a spray or fertilizer solution. Foliar applications must be renewed every year, but adding copper sulfate to the soil is a long-term strategy [2].

Acting as an Antifungal

Copper sulfate is a common primary component in certain commercial fungicides. These fungicides are usually combined with water and lime or soda ash, then sprayed onto the plants to achieve maximum effectiveness.

Copper sulfate is usually effective against a wide range of fungal pathogens, such as Alternaria, Aspergillus, Botrytis, Cladosporium, Fusarium, Monilinia, and Penicillium.

When using copper sulfate as an antifungal, always follow the instructions on the label. Be sure to wear gloves and protective clothing when handling this chemical, and avoid breathing in the dust or fumes. Keep children and pets away from areas where copper sulfate has been applied. Do not apply copper sulfate near water sources such as ponds or streams.

In order to be most effective, fungicides containing copper sulfate should be used preventatively; that is before infection occurs.

Acting as an Antifungal

Effects on Different Fruit

Copper has the potential to alter fruit sugar content and flavor in fruiting or flowering plants. Inhibition of photosynthesis, chlorophyll degradation, and oxidative stress are the main factors that copper ions cause to plants. The application of copper sulfate as a foliar spray can control powdery mildew, Phytophthora blight, Botrytis bunch rot, and other diseases on fruit crops in commercial agriculture.

The effects of copper sulfate spray application are most apparent in blueberry, tomato, watermelon, onion, parsnip, lettuce, beet, carrot, cabbage, eggplant, celery, spinach plants. When a plant’s conductivity is lowered due to water accumulation inside its leaves, the taste becomes sweeter.

Excess copper sulfate raises conductivity, lowering the sugar concentration and flavor intensity of the fruit. If you want to cultivate sweet fruits that aren’t watery, make sure you’re not applying too much copper sulfate to your plants [3].

Forms of Copper for Slug Control

The most simple types to employ are copper barriers. These may only protect a slug-free bed or planter box, including eggs. To accomplish this you will need some copper stripping and a metal tape measure. Remove the measuring tape from its holder, then bend it into an S-shape that can be placed in flowerbeds or around individual plants to protect them.

Copper barriers are also effective against slugs for internal intrusion, but they must be secured well enough not to fall over during rainstorms. You could use these barriers on pathways that lead underneath plants where slugs like to hide after dark since their slime trails left behind indicate slug activity.

If using bait is more your style, Copper sulfate can slowly kill snails and slugs over time by poisoning them once absorbed through the skin of their mucous membranes.

The Bordeaux mixture is another form of copper that may be utilized to battle these chewing pests. It is a fungicide made of hydrated lime and copper sulfate, which can be sprayed on plants.

It should be applied every seven to ten days when the temperature is below 85 degrees Fahrenheit, and it will protect your plants from powdery mildew, black rot, anthracnose, and other fungal diseases.

When using copper sulfate in your garden for pest control always mix it with water at a rate of about four teaspoons per gallon for spraying. You may also use Bordeaux mixture as a soil drench around susceptible plants. Check the weather forecast before applying because rain soon after application will wash the chemical away and you’ll need to reapply it [4].

Forms of Copper for Slug Control

How to Use Copper Sulfate as a Fungicide:

Fungi feed on plants, stealing minerals in the process. They attack and destroy plant cells, resulting in the decline and eventual death of the plant if they are left unchecked.

Some fungi flourish in damp conditions; others thrive in cold and moist environments, while still others flourish in warm and moist settings. If you discover fungus on your plants, use copper sulfate to eliminate them.

The correct ratio is essential since too much may also be harmful to plants [5]:

  1. Make a copper sulfate solution. 3 tablespoons of copper sulfate are mixed with a gallon of water to make 1 quart (approx. 1 liter) of solution. Stir until completely dissolved;
  2. Add 3 tablespoons of hydrated lime to the mixture and stir until completely dissolved;
  3. Pour the mixture into a pump-up sprayer. Spray the fungus-infected areas of the plant until they are fully covered. To prevent harming healthy portions of the plant, do not spray to areas that aren’t infected;
  4. Repeat the procedure in two weeks if the plant is still infested with fungus;


1. Is copper sulfate safe to use on vegetables?

Newer copper alloys have been found to be less harmful to plants and fruits. Some toxicity may still exist in some cases. Fungicides containing copper work by denaturing enzymes and other important proteins, as well as destroying pathogen cells. If enough copper is absorbed, it can also harm plant cells.

Copper sulfate is a very safe mineral, readily dissolving in water and combining with lime to stabilize the copper. It’s safe to use on plants because it doesn’t cause tissue damage when combined with lime [6].

2. How do you mix copper sulfate for plants?

Spraying on all the aerial parts of the plants, in the leaves, should be done in both the top and bottom.

A spray, water, and copper sulfate are all you need to make the product. To prepare the solution – 20 grams of copper sulfate must be combined in a liter of water and sprayed onto the plants. It’s vital to have the correct amount of medicine on hand since this lotion doesn’t last long and should only be used once. The compound will lose its healing qualities if you store it for longer than a day, therefore you must prepare the required quantity. This product is not harmful to plants, but it is poisonous for people and pets in the home, so use caution when applying it to plants and avoid contact with pets and children [7].

3. Is copper sulfate good for tomatoes?

Copper sulfate, formerly employed by vintners in the Bordeaux area of France to keep mold and other fungi off their grapes, is still effective for that purpose when used on certain fruits and vegetables, such as tomatoes [8].

4. How do you apply copper sulfate to fruit trees?

The copper sulfate fungicide should be applied at the same time as the fruit trees are ready to pick. The timing of application is just as important, if not more so than correctly applying copper sulfate when it comes to ensuring that the fungicide works properly without harming the fruit trees.

Depending on the type, brand, illnesses to be controlled, and species of fruit tree being treated, preparing the copper sulfate varies.

For example, one type of wettable powder instructs filling a pump spray tank 1/3 full with water before adding 5.6 ounces of the fungicide. Combine the components and add the remaining water until the tank is full. This combination will treat approximately 10,000 square feet and eliminate black rot on apple trees that are grown in USDA plant hardiness zones 4 through 8 (Malus Domestica) [9].

Useful Video: How to Use Copper Sulfate As a Fungicide