Mushroom (Agaricus) Dry Spawn
Enjoy the taste and satisfaction of your own home grown mushrooms!
Mushrooms can be grown throughout the year if suitable conditions can be provided. Sowing the spawn to harvesting the mushrooms can take as little as 10 to 12 weeks in ideal conditions. All you need s a cool cellar, garage, shed, cold frame or even under the greenhouse benching.
Sow January to December
Plant out January to December
Harvest January to December
The ideal temperature is 15c (60f). Temperatures over 20c (68f) can inhibit growth so mild summer heat can be a problem. Your mushrooms can be grown on straw, or using manure from the local stables. Mushrooms are produced in flushes; to pick, gently twist and lift, taking care not to damage any small developing mushrooms. Harvest at button stage when the cap cover the mushroom, or if preferred when the pink gills are visible underneath the cap.
I have had great success growing mushrooms in a polystyrene box in a cool dark storage cupboard in multi purpose compost.
Supplier growing instructions
The Cultivation of Mushrooms
Following these cultural directions, you can easily grow delicious, fresh mushrooms throughout the year. From the time of planting the spawn to harvesting will only take 10 to 12 weeks when grown under ideal conditions. Mushrooms develop best at a temperature of about 15c (60f). Below 10c (50f) the spawn becomes dormant but will survive frost, growth will recommence when temperatures rise. Do not allow the temperature to exceed 20c (68f). Do not use paraffin heaters as the fumes produced can have a detrimental effect on the growing mushrooms.
While a cool, damp cellar is probably the best, a garage, shed, cold frame or under the greenhouse staging may be used for growing mushrooms. Darkness is not essential.
Correctly prepared, the compost will produce mushrooms for 3 to 6 months, after which it can be dug into the garden as it is a first class, natural organic manure. Mushrooms grow on rotted down straw that can be obtained by composting either straw and suitable supplement or stable manure. As a rough guide, make about 25kg of straw manure to produce enough compost for a bed of about 0.20sq m (2sq ft).
Spawning
Make up the prepared compost into beds 20-25cm (8-10in) deep, ensuring that it is well compressed. For boxes , the compost layer should be 15-20 (6-8in) deep. Ensure that the compost does not heat up after being made into beds or boxes. The temperature of the compost must not exceed 21c (70f) at spawning. The grains of spawn should be scattered evenly over the compost surface and then mixed in to a depth of 5-8cm (2-3in). Press the compost firmly down and cover with damp newspaper to keep the surface moist.
Casing
A few days after spawning, thin white threads will grow from the grain into the compost. When this is fully established, usually after 10-14 days the newspaper should be removed. If temperatures have been low or fluctuating allow 21 to 28 days. Cover the compost with 3cm (1¼ in) of clean, moist garden soil, free from pests or organic material. It is best taken from a depth of at least 30cm (1ft). a mixture of 2 parts of well moistened peat and 1 part chalk, ideally granulated to 9mm (1/8 in) to dust or limestone chipping may be used instead. If peat is used as the casing material a layer of 4-5cm (1½-2 in) should be applied.
Watering
The casing material should be kept moist but not wet. If too much water is applied, this will soak through the compost and could damage the spawn. Water with a fine rose on the watering can or use a mist sprayer.
Harvesting
Mushrooms grow in flushes. To pick, gently twist the cap and pull away from bed, taking care not to damage small mushrooms that are developing. Depending on the temperature maintained, mushrooms will be ready 5 to 12 days from their first appearance and they are best for eating when the caps have opened to reveal the pink gills underneath and these are just beginning to turn brown. Remove from the beds and burn any stumps or broken stems. Holes in the casing material should be filled with fresh soil.
Helpful tips: Keep free from weeds, do not over-water, do not allow to dry out.