What is loam?

Basically loam is a soil, which contains equal amounts of clay, silt and sand, enriched with humus, i.e. decayed organic matter.

Loams that contain larger proportions of sand are termed 'sandy loams', and those with larger amounts of clay are 'clay loams'.

Could you give me the formula for John Innes potting compost?

John Innes Potting compost No 1 is

7 parts sterilised loam,

3 parts peat,

2 parts coarse sand (all parts by volume).

Add 28gms (1oz) of John Innes base fertiliser, and 6gms (¼oz) of chalk to each 10 litres of mixed loam, peat & sand

n.b double/triple fertiliser for Ji 2 & 3 respectively.

Can I place shredded privet, holly, hazel, berberis and chestnut trimmings on the compost heap to use as a mulch?

Yes, the trimmings from your hedges may be composted and when well rotted used as a mulch.

What are the pro and cons of using a soil-less compost against a loam based one?

Soil-less Pros;

Quite inexpensive.

Quality is generally consistent.

Light to handle and pleasant to use

Some types of plants grow better in it.

Against;

Can be difficult to re-moisten if it dries out

It can soon run out of nutrients.

Loam based pros;

It contains a larger reserve of plant nutrients, so the plants need less additional fertilizer.

It rarely run out of trace elements.

It easier remoistened if it should dry out.

The weight can be useful in counter-balancing container grown plants.

Some types of plants grow better in loam-based compost.

Against;

Generally more expensive

Heavier to carry.

Less pleasant to handle when wet

The quality can vary, from different suppliers due to the quality and source of the loam.

It deteriorates in storage.