There is something
especially exciting about the sight of the first
flush of mushrooms breaking through the surface
– we should feel the same way about germinating
lettuce seeds…but we don’t. There
are two reasons – with mushrooms we know
that it will take no more than a week or two for
the tiny white pinheads to turn into button mushrooms
ready for picking. Secondly, we also know that
mushrooms are notoriously unpredictable –
an outdoor planting is indeed a gamble; using
home-made compost reduces but does not remove
the risk and only the use of ready-spawned containers
provides anything like the predictability associated
with other vegetables.
· You may or may not be successful in raising
mushrooms in a corner of your lawn. It will certainly
have to be in a shady spot and the ground below
will have to be enriched with well-rotted manure.
Even if you are successful, there are the drawbacks
of being unable to cut the grass when cropping
starts and weeds cannot be treated by chemical
· If the above points act as a challenge
rather than a deterrent, pick a damp day in spring
or autumn and use golf-ball sized blocks of spawn,
setting them about 2in (5cm) below the surface
at 12in (30cm) spacings.
Anywhere indoors will do provided that the container
or bed is shaded from direct sunlight and the
temperature is in the 55-65°F (12-18°C)
range. Large fluctuations in temperature will
slow down production – both cold and hot
conditions will stop it. You will need specially-prepared
compost which is hard to make at home, although
you may be lucky enough to find a local supplier.
This will have to be planted with mushroom spawn
and properly tended to ensure success –
a much easier course is to buy a ready-spawned
container of compost from a garden centre or mail
Start from scratch method
· Start with stable manure or straw plus
an activator. You will need a large heap, about
5ft x 5ft x 5ft (1.5m x 1.5m x 1.5m), to be reasonably
sure of success and it must be well watered at
the start. Leave covered until the temperature
reaches at least 140°F (60°C) –
then turn every week until the heap is dark brown,
crumbly and sweet-smelling.
· Fill boxes or buckets 9-12in (23-30cm)
deep – firm down with your fingers. When
the temperature has fallen to 75°F (24°C)
the surface is ready for spawning.
· Two types of spawn are available –
fungus-impregnated manure (block spawn) or impregnated
rye (grain spawn). Block spawn is the easier one
to use – push golf-ball sized pieces about
1in (2.5cm) below the surface at 12in (30cm) spacings.
· After a couple of weeks the spawn will
have started to ‘run’ – white
threads will be seen on the surface. At this stage
add a 2in (5cm) layer of moist casing mixture
(2 parts peat, 1 part chalk).
· Buy a bucket or bag of ready-spawned
compost. Avoid any pack which has obviously been
in store for a long time and make sure that you
start the pack into growth within 3 weeks of purchase.
Looking after the crop
· A temperature of 55-65°F (12-18°C)
is necessary to promote the active development
of the white fungal threads (mycelium) below the
surface and the appearance of the edible fruiting
bodies above. The casing should be kept moist
but not wet by careful syringing with water.
· The first flush will be ready for picking
as button mushrooms 4-6 weeks after casing –
these buttons will open into flats in about 7
days. Once the first flush has been harvested
there will be a pause of about 2 weeks before
the next flush appears. Cropping normally continues
for about 8 weeks.
· Do not harvest mushrooms by cutting the
stalks. Twist the mushroom upwards, disturbing
the compost as little as possible. Cut away broken
stalks and fill holes with casing mixture.
· After the final flush has been picked,
use the spent manure in the garden – do
not try to re-spawn for a second crop.