BLOG: Know Your Soils & Mulches

BLOG: Know Your Soils & Mulches

Do you know the difference between a soil conditioner, top soil, a mulch and compost? If not then read on. To obtain the best results for your borders, vegetable plots, fruit trees and shrubs you need to understand your soil condition and what is required to make it healthy and working hard for your garden.

Top Soil

Let's begin with top soil. Top soil is not a soil conditioner and only contains a minimum of nutrients, if any. You use top soil to bulk up your borders. Look at it as a filler. Perhaps you have removed some old trees and shrubs and it has left huge holes in your garden. Use top soil to fill in those holes or to add height to sunken beds and borders.

Soil Conditioner

You use soil conditioners to improve the structure of your soil. Generally it is composted from a blend of farm manure and tree bark and breaks down very quickly. If your soil is compacted, sandy or heavy clay then soil conditioner will help break up the density to make it more 'fluffy' and to improve drainage.  It also boosts nutrients, including vital beneficial micro-organisms as it helps to unlock compacted soil and release the existing nutrients lying dormant. It provides a source of slow releasing nutrients that adds humus (Humus is Latin for 'Soil'), which is rich dark organic matter. Finally, it will help to retain moisture in soil that already has good structure -i.e it isn't compacted or of a clay nature.


Did you know compost is often referred to as 'Black Gold'? It is organic matter (this is any material that occurs naturally in nature) that has decomposed such as leaves, twigs and farmyard manure. Compost with its valuable trace elements is the finest of materials to add to your soil. Its carbon nitrogen ratio (30 parts carbon to 1 part nitrogen -this is the ratio required for micro-organisms to sustain health) means there is more nitrogen to feed your plants. You can use to add to top soil and existing soil. It encourages earthworms, which in turn helps to aerate the soil.  Compost will also stabilise the PH levels and you will need to check the compost you buy as it will tell you what percentage of PH it contains and depending on your soil type i.e. acid or alkaline this will give you an indication of how much to use or whether that particular compost is right for your soil. It will also make an excellent mulch.


Mulches are generally made up of coarse materials such as bark, wood chips, and straw. Apply to beds and borders and around the foot of shrubs and trees. Mulch allows rainwater to filter through to the soil while also helping to retain moisture. This is particularly important during the warmer months of summer or for prolonged dry spells. It will eventually break down over a period of a couple of years when it will be time to add another layer.

So to have a colourful and flourishing garden - its top soil, soil conditioner, compost then mulch!



Posted by Tina Abbey
24th May 2019

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