John Innes was a very successful nineteenth century property and land dealer and was one
of the founders of the City of London Real Property Company. On his death in 1904 he
bequeathed his estate to be used for the promotion of horticultural instruction,
experimentation and research. The result was the establishment, in 1910, of the John
Innes Horticultural Institution, on 5 acres of farmland adjoining Merton Park, Surrey.
Before John Innes composts were introduced, gardeners and commercial horticulturists relied
on 'good' garden soil, or used composts produced to their own recipe, for potting seeds and
plants. It was common to find a different compost formulation being used for each plant
species being grown. These composts and soils were not usually sterilised and so seedlings
were often damaged or destroyed by soil-borne pests and diseases. These composts and soils
were of variable quality as were the fertilizers added to them to promote plant growth. The
consequent nutritional imbalances led to plants being either too "soft" and therefore liable
to disease, or very "hard" and slow growing.
In the 1930's William Lawrence and John Newell, two scientists at the John Innes Horticultural
Institute, set out to formulate composts that would give consistently good and reliable results.
Their particular motivation was the difficulty they were having in growing Chinese Primrose
(Primula sinensis) for experimental purposes. Their objective was to obtain much better and
more reliable germination and growth among their experimental materials by standardizing
growing conditions, including the growing medium. Through experimentation they established
methods of heat sterilising the compost to destroy pests and diseases that did not cause any
checks to plant growth. They also determined the physical and nutrition qualities needed in
compost to achieve optimum plant growth. Lawrence and Newell also took into account the need
to alter the nutritional status of the compost according to the plant's growth stage. Their
research led to the introduction of the two standard composts, one for seed sowing and one
for potting, which revolutionised the growing of pot plants.
(Extracted from the web-site of the JI Centre January 2007)