Why Use Horticultural Grit?

Why Use Horticultural Grit?

Why Use Horticultural Grit

Horticultural grit is a finely graded, washed, and sized stones used to enhance drainage in composts. These particles are typically 2-4mm in size.

Often referred to as builder’s sand, horticultural grit is a useful additive for both gardeners and landscapers. However, there are a few important points to consider before you use it.

Improves Soil Aeration

When the soil is waterlogged or compacted, plant roots cannot absorb oxygen. Oxygen is critical for the growth of healthy root systems, and it’s also essential for allowing microorganisms to thrive in the soil.

Using horticultural grit or sharp sand to improve soil aeration is a simple way to keep the nutrient and water levels balanced in your garden. This is especially important for clay-rich soil, which may be left overwaterlogged and compacted after heavy rains.

Horticultural grit is a gritty sand made from crushed rock, such as limestone or granite. It is a common alternative to builders sand, which can be difficult to source and can be expensive.

The angular edges of horticultural grit, combined with its slight variations in size and shape, create small pockets that help hold air and water. This is an ideal product for opening up heavy clay soils and helps reduce clumping in sticky clay soils too. It can also be used to build scree gardens, which mimic natural features that are found in mountainous areas.

Enhances Drainage

Horticultural grit is one of the best-known soil improvers that have several benefits for your garden. It is also one of the most versatile and enduring products available, making it a value-adding material for any gardener.

It is composed of small angular stones that are crushed and washed to remove any other soil content. It is free of salts and lime, allowing it to be used with any type of soil without raising or lowering its pH level.

The angular surface of the grit helps produce small pockets in the soil that hold air and water. These pockets allow the soil to be aerated, which is essential for plant growth.

Using horticultural grit with other growing mediums like sand, vermiculite, clay, or potting mix can improve the balance between water retention and drainage, especially in well-drained soils. It can also enhance the aeration of poorly drained soils by adding organic matter.

Enhances Root Growth

When used properly, horticultural grit can enhance the root growth of houseplants and other plants. This is because it improves soil aeration and drainage.

It also makes the soil less compact, which promotes more air spaces and allows more water to permeate into the ground. This enables the roots to grow more effectively and prevents rot.

Horticultural grit is made from crushed rocks like limestone or granite. This rock is often angular, making it easier to break down into small pieces that increase surface area.

This type of stone is often used for potting alpine plants, as they thrive in rocky soils and sunny locations.

Unlike gravel or rocks, which can clog the bottom of plant containers and create water saturation zones that deteriorate the plants’ root systems, horticultural grit actually improves the drainage ability of the soil in the pot.


Horticultural grit is used for a number of different decorative applications, including top-dressing plant pots and containers. It’s also used for potting compost, as it provides extra drainage and opens up the structure of the compost to enable better water and nutrient uptake.

Another popular use for this grit is to build scree gardens, which emulate natural features found in mountainous areas. This material naturally breaks down into pieces with angular edges, giving it a larger surface area than its size suggests, improving soil aeration and drainage.

Alternatively, you can choose to use horticultural grit to create a decorative mulch around plants. This will prevent dust and leaves from blowing off the plants, making them easier to keep tidy.