Compost additives: what do they do?

Vermiculite is a natural mineral that is great at absorbing liquids, is lightweight and provides the perfect environment for plants to grow when added to compost. Vermiculite is ideal for seed germination and is typically used in potting compost. Vermiculite helps to stimulate root growth, giving plants quicker anchorage and improved uptake of nutrients.

Benefits

• High water holding capacity
• Good air holding capacity
• Non-abrasive and non-irritant
• Attracts excess nutrients
• Facilitates re-wetting
• High cation-exchange capacity
• Neutral alkalinity
• Does not deteriorate in storage (if kept dry)
• Free from disease, weeds and insects
• Insulates and minimises soil temperature fluctuations Inorganic and sterile
• No known toxicity or fire hazard

Sinclair Fine Vermiculite

Fine vermiculite for mixing into compost to increase nutrient and water retention. Sinclair Vermiculite Fine is a natural, non-toxic addition to compost mix that improves aeration and drainage. Fine vermiculite can also provide insulation to seedlings in the nursery.

SHOP NOW

Sinclair Horticultural Grade Vermiculite

Sinclair Horticultural Grade Vermiculite is porous so it helps retain water & nutrients in the soil for release to plants. Lightweight and has thermal insulation properties which makes it ideal for use as a pot topper.

SHOP NOW

Perlite is the name for a naturally occurring siliceous rock. When heated, it has the capacity to expand from four to twenty times its original volume. This is due to the rapid expansion of water within perlite, which creates the extremely light perlite that we use for gardening.

The main function of perlite for the gardener is to aid water retention and aeration as well as improve compost mixtures.

Benefits 

• Prevents compaction 
• Improves aeration and drainage better than vermiculite 
• Stimulates root initiation and vigorous growth
• Holds moisture but does not become soggy 
• Almost neutral pH 
• Does not decompose 
• Free from disease, weeds and insects
• Insulates and minimises temperature fluctuations 
  
• Inorganic, inert and sterile 
• No known toxicity or fire hazard 

Garden lime is used to neutralise soil acidity and is ground from limestone rocks and provides calcium carbonate and magnesium carbonate to the soil. Calcium helps plants to grow healthy roots and stems. Magnesium aids with photosynthesis in lawns. 

Benefits

• Neutralised soil acidity
• Contains calcium and magnesium carbonates
• Enabled healthy roots and stems
• Apply in winter before growing crops in spring
• Increases pH

Soil improvers and conditioners are used to improver the overall condition and fertility of the soil structure. The substrate is added to the soil and worked in to enable a healthy uptake of nutrients which in turn benefit plants and the overall quality of the soil. 

Benefits 

• Contains organic material to improve soil structure
• Aids soil structure by providing nutrients, improving aeration and water holding capacity
• Helps to prevent compaction
• Depending on the ingredients, soil improvers can raise or lower the soils pH level

To find out your soil type, take a look at our soil health guide.

Topsoil contains some of the highest concentration of organisms and nutrients and gives your garden a helping hand by enriching your existing soil. It enhances the quality of poor soil types, to help with plant and vegetable growth. Topsoil can contain more nutrients and organic matter than regular soil, meaning it works with you to provide balanced nutrients to nurture your plants. Using Topsoil means overtime your will improve the quality of your soil in the long run, which is great for the future of your growing.

Benefits

• Can be used in raised beds and planters as well as a topdressing for lawns
• Contains optimum levels of phosphorus, magnesium and potassium as well as beneficial pH levels
• The natural fertility of topsoil promotes healthy growth
• Enhances existing soil types

Mulch is typically an organic material which is added to the soil surface, mulch helps to suppress weeds and improve water retention as well as benefitting the soil's overall health and fertility. It also makes the garden look neat and tidy!

Benefits

• Helps to suppress weeds
• Improves soil moisture retention
• Boosts soil health and fertility
• Improves the appearance of the garden

To shop the full range of mulch we have available at The Garden Superstore, click the button below.

SHOP NOW