This delicious fungus, which grows as well in full darkness as in complete light, is equal in food value to such root crops as onion, turnip, carrot. Its requirements are heat and moisture, stable manure and soil. There are several ways of growing mushrooms, and the crop is always worth raising, at all times of the year.
Varieties include Brown and White.
Mushrooms are raised by plant- ing pieces of material (manure and soil mixed) impregnated with spawn which, under suitable conditions, spreads through the prepared bed as whitish threads (the roots); these send up the mushrooms, which are the fruit. Spores, corresponding to the seeds of other plants, are produced in vast numbers on the gills beneath the mushroom’s cap. These dust-like spores are cultivated by a special process, and the product – for planting – is sold in cartons or in the form of bricks.
A brick of mushroom spawn is 8 in. or 9 in. long, 5 in. or 6 in. wide and about 2 in. thick, and for planting is broken into about eight pieces. These pieces are inserted 8 in. or 9 in. apart and 2 in. deep in the prepared bed. The contents of a I-pint carton are sufficient to impregnate 30 to 40 sq. ft. of bed.
Ready for Use.
Mushrooms are obtainable all the year round – outdoors during summer and autumn, the rest of the year in a frame, greenhouse, shed or cellar. The first mushrooms appear six to nine weeks after planting in a bed of manure.
When and Where to Plant.
Warmth being a prime consideration, mushrooms are raised with least trouble in summer and autumn in the open. Crops to be available in late autumn, winter and spring need the shelter of a frame or building where the temperature by night does not fall below about 55 degrees.
Fortunately a bed is not essential, though very desirable, for growing a few mushrooms. The spawn can be planted in a corner of a lawn or in the turf of a meadow or orchard, and in large flower pots and boxes and tubs.
Mushrooms in Turf.
If a corner of the lawn is used for growing mushrooms it should be wired off to preserve it from trampling feet and the lawn mower. Planted in orchard or meadow, mushrooms can be left to take their chance. The method of planting consists in raising pieces of the turf, 1 in. thick and of any convenient area – say the width of a spade blade and 1 ft. long – at intervals of about 3 ft. Soil is taken out, and replaced with more or less fresh stable manure (horse droppings) trodden down firmly; in this a couple of pieces of spawn are planted, a few inches apart, so that these lie just below the surface of the manure.
The spawn is then covered with enough soil to bring the surface of the piece of turf, when this is replaced, level with the surrounding grass. The piece of turf should be firmed back into place by treading or rolling.
Planted during May or June, mushrooms should make their appearance during August and
September, provided the position is sunny and the soil is well drained. Clay and chalk are unsuitable. In favourable circumstances successive years will be marked by the appearance of crops covering an increasing area, for the root threads travel well. Inducement to do so is provided by scattering a handful of agricultural salt over each square yard of the area, each June; or saltpetre (nitrate of potash) may be used, 1 ounce to the square yard.
The depth of manure placed in each planting hole will be governed by the quantity available. If it can be 9 in. or 10 in. thick this will be ideal; a couple of inches will be better than none.
Mushrooms in Pots, Boxes, Tubs.
Flower pots of 10-in. diameter, or boxes or tubs about 9 in. deep, filled firmly to within 1 in. of the top with stable manure, will take the place of the regulation mushroom bed. Spawn is planted 1 in. deep in the manure (which must be made quite firm), and the pot, box or tub is then filled to the top with sifted soil, and this in turn is made firm by patting it with the back of a spade. Clean straw or bracken is then placed on top, to the depth of 2 in. or 3 in., to conserve heat and moisture.
Planted in May, June or July, die receptacles can stand out in the open, in the sun and out of cold winds, covered against heavy rain (when necessary) with old mats, sacks, or something similar; or they can be placed in an airy shed. For winter and early spring crops they must be under cover, a greenhouse with a minimum night temperature of about 55 degrees, or a warm cellar, being most suitable.
When more than quite a small quantity of manure is to be used it should be collected and prepared as explained below.
Collecting the Material.
If a cartload of fresh stable manure is available at one time this should be spread out under some sort of cover – in an open shed, or in a barn – or corrugated iron sheets, old linoleum, etc.., be used to roof it over. The object of this is to prevent it becoming sodden with rain or snow or being dried by sun or wind during the time the manure is being prepared for planting.
If road droppings have to be collected, a small quantity at a time, these should be stored as above until the desired bulk is secured.
Preparing the Material.
The manure is to be forked over at two-day intervals for about a fortnight, if for use during late spring and summer; for about a week in the cold months. The object is to let out rank heat and gases. Long straws should be removed while the manure is being shaken out with the fork; straws less than I ft. in length can remain.
Proceedings begin with the piling up of the collected manure. This is then unpiled with the fork two days later, and turned inside out during repiling; that is, the shaken-out manure is piled up again with the material that was at the outside now in the centre. At the next forking the centre will become the outside, and so on until the end of the week or fortnight. By then the manure will have lost its strong odour, and should be just moist enough to bind together when pressed in the hand.
If it is too dry it must be moistened, with tepid water given from a can fitted with a fine rose, the heap being taken down again for this purpose. Water is then sprinkled over each layer as the heap is rebuilt. The manure must not be made so wet that moisture can be squeezed out.
These preparations satisfactorily completed, the manure can be filled into boxes or whatever receptacles are to be used; or packed into a frame; or made up into an outdoor or an indoor bed.
Adding Leaves to Manure
To make the prepared material go farther, slightly moist (not sodden) tree leaves can be added, the best for the purpose being beech or oak, the addition being made just before a bed is to be built up or a frame or box filled. Leaves may be mixed with the manure to the extent of about one-third of the latter’s bulk.
Mushrooms in a Frame.
A hotbed frame occupied in summer by a cucumber or melon plant will produce a few mushrooms at the same time if spawn is planted in the bed, here and there, near to the ends and sides, round about July. Spawn can also be planted in the area of manure outside the frame, covered with 2 in. of sifted soil and then a few inches of dry bracken or straw.
An ordinary cold frame (not placed on heating material) to be pressed into service for mushroom growing should have prepared manure (plus leaves if necessary) firmed into it, to receive the spawn. The material needs to be shaken out with the fork into the frame, in level layers, each layer being trodden down before the next goes in. Firming should be given special attention along the sides and ends. If the material is left loose, great heat will be generated and as quickly dissipated. After the final treading the material should be about I ft. deep – a few inches deeper if possible, especially if a winter or spring crop is aimed at. The spawn should not be planted until the temperature of the made-up material has been tested and found to be suitable.
Taking the Temperature. It is important that the temperature of the bed should not be too high when the spawn is planted. For three or four days after making up, the heat will increase. When it is on the down grade – has fallen to about 80 degrees – is the time to insert the spawn.
Temperature can be taken with a thermometer pushed about 8 in. into the bed. Or it can be tested by plunging a stake into the manure, leaving it there a few hours, then withdrawing it and grasping the hot lower end. If it is too hot for the bare hand to continue gripping, spawning must be delayed until further daily tests proclaim the temperature to be on the decline. A temperature as low as about 50 degrees will do, but mushrooms will be longer in making an appearance.
Planting the Frame Bed.
Holes are made in the manure, about 2 in. deep and 9 in. apart each way, and in each spawn is planted. Manure is replaced over the spawn, then the whole surface is covered with sifted soil, this to be 2 in. deep after being patted down with the flat of the spade.
Chalky, clayey or dusty soil is useless for the purpose. It must be good, fertile soil, free from stones and bits of rubbish, and just moist enough to ball up when a handful is compressed.
Those operations completed, the frame light is shut right down, to maintain a close and moist atmosphere, and covered over with sack- ing, matting, or straw or bracken to keep the heat inside the frame.
Outdoor Mushroom Bed.
Backed by a fence or wall facing the south, with some shelter against winds from the north and east, an outdoor mushroom bed is ideally situated. It can be of any dimensions, of course, but the depth should be not less than about 14 in.; the bed to produce winter or early spring crops would be better if 2 ft. deep when firmed down. Usually the beds are about 21 ft. wide, with either flat or sloping top. The object of the sloping top is to shoot off heavy rains or prevent snow (in winter) remaining long in position. The slope may be from the back down to the front; or back and front may slope, with a flat ridge about 6 in. wide.
The outdoor bed is made up in a similar manner to a frame bed, and when its temperature is satisfactory spawn is inserted in the manure 2 in. deep and at intervals of 9 in., the surface then covered with 2 in. of sifted soil beaten firm, and a bed could be located in a draught-free shed – cold draughts being one of the things to avoid.
A convenient position for bed, pots, tubs or boxes in the greenhouse is under the staging, but precautions need to be taken against water given to pot plants on the staging dripping down on to the bed, etc.. Dry heat is as bad as cold draughts. The necessary moist atmosphere can be maintained by syringing walls and floors with tepid water whenever the air begins to smell dry.
Not until the first mushrooms appear is it necessary, as a rule, to give any water. The soil covering should be watched, and occasionally tested by a poked-in finger. If the finger, inserted full length, registers a moist condition, the watering can will remain idle. When the soil feels dry, or dryish, give water with the chill taken off. Whilst mushrooms are being produced, an occasional covering of straw or bracken put on to the depth of 1 ft. or so. Pieces of board should be placed on top to keep this covering material in place, with the addition of sacking, old lengths of linoleum or anything, similar as winter protection.
The soil over the manure is put on from the bottom upwards if the bed has a sloping top, in 2-in. thick layers 4 in. or 5 in. deep. There is then no difficulty in getting the soil to stay put.
Indoor Mushroom Bed.
In making up a bed in cellar or greenhouse for a winter crop the aim should be a minimum depth of 9 in. of prepared manure, with an extra 3 in. or 4 in. if leaves are mixed in. The bed that is 2 ft. thick will naturally give earlier mushrooms and the supply will be more prolonged. The cellar or greenhouse should have a night temperature in winter of about 55 degrees. During summer the tonic will be helpful – a dessertspoonful of salt, or saltpetre (nitrate of potash), dissolved in each gallon of water used.
While those attentions are being given the straw or bracken covering will need to be temporarily removed.
Woodlice and Maggots.
Quarter-inch thick slices of carrot or potato placed here and there under the straw or bracken covering will serve as traps for woodlice, which sometimes abound and do their best to spoil a good crop. This bait should be examined every day, and the wood-lice found below collected and disposed of. Maggots of a small fly are occasionally troublesome. These grubs burrow into the mushrooms and render them worthless – unless one can stomach cooked maggot. This is a hot-weather nuisance, and unfortunately nothing can be done about it.
Gathering the Mushrooms.
To get at the crop, when it begins to appear, the straw or bracken covering has to be removed, then replaced. This needs to be done carefully, or some of the crop may be damaged. The method of gathering docs not involve a knife. Each mushroom is gripped by the stalk, which is twisted and pulled so that it comes away at the base. The small hole it leaves is then filled with a little of the surrounding soil. Use of the knife is frowned upon because cut ends of stems are likely to decay, and that leads to considerable trouble.
Clusters of mushrooms will continue to appear for two, three, perhaps four months, according to circumstances. The material of the bed then serves another purpose; it is grand for digging into the vegetable ground and for making soil mixtures for filling seed pots and boxes, and for pricking out seedlings and for potting.
Preparing for Table.
Cut off lower part of stalks and skin the top of the caps before frying, baking, stewing, pickling or making into ketchup.
As a food the mushroom ranks with carrot, turnip, onion, beetroot, and can take the place of those vegetables in the diet of diabetics.