Bentonite Fines 1kg

Is Bentonite readily available?

Bentonite is mined from natural clay deposits, then dried, crushed or milled into different grades. Because it is a natural material, the quality and mineral balance can vary depending on where it is mined. There are different types of bentonite, including sodium bentonite, calcium bentonite and mixed sodium-calcium bentonite. Sodium bentonite swells more strongly, while calcium bentonite is often preferred for soil conditioning because it is less likely to become overly sticky or slippery when used correctly.

What is Bentonite used for?

Bentonite has many uses outside gardening and horticulture. It is used in:

• Cat litter, because it absorbs moisture and odours
• Dam sealing and pond sealing, because some types swell and help reduce water loss
• Wine and juice clarification
• Animal feed pellets as a binding agent
• Foundry work and drilling muds
• Soil improvement, especially in sandy or low-clay soils

In Horticulture

In gardening and horticulture, Bentonite Clay Fines are mainly used to improve soil structure, water retention and nutrient holding capacity. Sandy soils usually drain quickly and have a low Cation Exchange Capacity, meaning nutrients can leach away before plants can use them. Clay and organic matter help improve this nutrient-holding ability.

Bentonite can help by adding fine clay particles to the soil. These particles can hold onto moisture and plant nutrients, making them more available to plant roots over time. Research on bentonite as a soil amendment has found that it can improve field water-holding capacity and plant-available water, especially in dry or sandy soil conditions.

Some uses in horticulture include:

• Garden beds - Mix Bentonite Clay Fines thoroughly into the topsoil with compost, manure or other organic matter. It is best used in sandy or free-draining soils where water and nutrients are easily lost.
• Pot plants - Add a small amount to potting mix to help retain moisture and nutrients. Do not overuse it, as too much fine clay can make a mix heavy and poorly drained.
• Vegetable gardens - Use when preparing beds for vegetables that need steady moisture, such as leafy greens, brassicas, corn, tomatoes and cucumbers.
• Lawns - Can be used in sandy lawns to improve moisture retention. It should be spread lightly and watered in well, or mixed with sand/compost before applying.
• Compost - A light sprinkle through compost may help hold onto nutrients and reduce nutrient loss, especially nitrogen. It should not be added in thick layers, as it may become sticky or clumpy.
• New planting holes - Mix a small amount through the backfill soil before planting. Avoid placing a solid layer of bentonite at the bottom of the hole, as this may interfere with drainage.

Important: Mix it well

Bentonite should always be mixed well through the soil, compost or potting mix. Do not leave it sitting as a thick layer on top of the soil or at the bottom of a pot. When fine clay becomes wet, it can form a dense layer that may reduce air flow and drainage.

For sandy soils, small repeated applications are usually safer than adding too much at once. Recent sandy-soil amendment research also notes that clay can be helpful, but too much clay may reduce productivity if it creates other soil problems, so moderation is important.

Health and Safety

Bentonite itself is a natural clay, but the fine dust can irritate the lungs, eyes and throat. When applying it, avoid breathing in the dust. Use a dust mask, apply on a still day, and keep it away from children and pets during application.

Please note: This product is sold as a garden soil conditioner only. It is not food-grade, pharmaceutical-grade or intended for internal, cosmetic or medicinal use.

Did You Know? Cation Exchange Capacity

Cation Exchange Capacity, often shortened to CEC, is a measure of how well soil can hold onto positively charged nutrients such as calcium, magnesium and potassium. These nutrients are held by negatively charged clay and humus particles in the soil. The NSW DPI describes these clay and humus particles as a kind of nutrient storehouse for plant roots.

Soils with higher CEC generally hold nutrients and moisture better than low CEC soils. Sandy soils usually have very low CEC, while soils with more clay and organic matter usually have higher CEC and better nutrient retention.

This is why Bentonite Clay Fines can be useful in sandy garden soils. It helps add fine clay particles that hold moisture and nutrients, giving plants a better chance to access them before they wash away.