1910s Timeline - John Innes Centre

1934 Research on ‘John Innes’
composts begins
Only 22 per cent of the Primula
sinensis seeds sown in 1933
survive to give living plants. This
loss is a catastrophe for the
geneticists and results in W J C
Lawrence beginning to look for
an alternative growing medium.
He is helped at the start of his
search by Messrs Suttons of
Reading whose resident expert
on primulas had already devised
a successful special compost.
Lawrence adapts the recipe,
changing three variables at
once, and in mid-winter 1934
1,000 plants die or wilt as
before. J B S Haldane said he
should be sacked for his
foolishness! To prevent another
disaster in the 1935 crop,
Lawrence begins to investigate
the whole procedure of making
seed and potting composts.
Assisted by John Newell, he
makes a large number of tests
on the ingredients used for
potting composts, including pH
determinations, seed
germinating capacity, and the
effect of steam sterilisation on
germination and growth. His
aim is to produce a standard
sterilised compost giving
superior results. By 1935
Lawrence has established the
optimum amounts of N, P and K
fertilisers and introduced two
standard soils for use at JIHI,
one for sowing and one for
potting, while continuing his
investigations. His work pays
off: the 1935-36 crop of primulas
is one of the best crops the JIHI
has ever had and ‘primula wilt’ is
eradicated. Lawrence begins to
consider whether the composts
will work for all species and
continues testing. After
hundreds of trials, Lawrence
arrives at two basic composts, a
base fertiliser for use in the
potting compost and a standard
feed. The formulae of these, as
yet unnamed composts, are
published in 1938. The name
‘John Innes Compost’ is allotted
in 1938-39; the horticultural
retail trade in the composts
makes ‘John Innes’ a household
name.
Before John Innes composts
were developed, gardeners and
horticulturalists made up their
own mixtures. These were
subject to so many
unstandardised conditions that
it was impossible to identify the
cause of failures to grow
healthy, vigorous plants, and
sterilised soil was hardly ever
used for potting, either in
private or commercial practice.
It was common to raise three
times as many seeds as the
number of plants required to
allow for deaths from damping
off and other troubles.
See also:
W. J. C. Lawrence, Catch the
tide: adventures in horticultural
research, London: Grower
Books, 1980.
W J C Lawrence
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