Topsoil – and topsoil suppliers – can vary greatly in quality, so it always pays to look around before placing an order. Local recommendations are often one of the best ways of choosing a supplier.
When buying topsoil consider whether you really need soil of top quality. If you do, do you require a particularly good grade or would a more general grade suffice? Most good suppliers will offer a range of grades. It is important that you are specific about your requirements as the terminology used will vary from supplier to supplier. Describe your situation/requirement to them as they may be able to recommend a material better suited to your situation.
There are three common types of topsoil:
Sterilised loam/top soil
This can be expensive but should not bring in weed seeds. Commonly used to build up flower borders or create new beds.
Screened medium loam
This can be bought in differing screen size grades. Coarser grades are particularly useful for turf laying while finer grades are good for top dressing lawns.
Medium loam/top soil
This tends to be supplied ‘as dug’ (unscreened) and is commonly used to build up areas where volume rather than quality is required.
In general try to see the topsoil before you buy it, look out for high stone content, thick fibrous roots and contaminants such as glass and brick. Inspection will enable you to discuss any concerns you may have before you actually buy it. Ask the supplier where it is coming from and whether it all has the same origin (building sites are often used as a source and the quality can be variable). If the supplier has had soil analyses undertaken request a copy. If they claim it is good and state facts and figures request these details in writing.
The following criteria can be used as a guide against any analysis report a supplier offers you.
- pH = 5.5 – 7.8
- Phosphorus (P) Index min = 2
- Potassium (K) Index min = 2
- Magnesium (Mg) Index min = 1
Paul Alexander