Increased by seeds, and by bulbels, which are obtained by lifting the old bulbs early in the autumn, about every second year.
Mushroom (Agaricus campestris).
Break up the commercial spawn into pieces about as large as a hen’s egg, and plant it in drills or holes, using from one-half pound to a pound of spawn to each square yard of bed.
The spawn is the mycelium of the fungus held in a mass or “brick” of earth and manure. Various methods are employed for making the spawn, but the essentials of them all are that the body of the brick shall be composed of a porous and light material, which can be compressed into a compact mass; fresh mycelium must be communicated to this mass, and then a mild heat must be applied, until the whole mass is permeated by the mycelium. The mass should be kept in heat until the whole of it assumes a somewhat cloudy look, but not until the threads of the mycelium can be seen. Ordinarily, fresh horse manure, cow manure and good loam are mixed together in about equal proportions, enough water being added to render the material of the consistency of mortar. It is then spread upon the floor or in large vats, until sufficiently dry to be cut into bricks. When these are tolerably well dried, mycelium from a mushroom bed or from other bricks is inserted in the side of each brick. A bit of spawn about the size of a small walnut is thus inserted, and the hole is plugged up. The bricks are now placed in a mild covered hot-bed, with a bottom heat of 55° to 65°, and left there until the clouded appearance indicates that the mycelium has extended throughout the mass. Soil from a good mushroom bed is sometimes used to sow new beds, in place of commercial spawn. Old clumps of mushrooms may be allowed to become dry, and they may then be mixed into a bed. The spores will then stock the soil and produce a new crop. The full-grown mushroom may be laid upon white paper until the spores are discharged, and these spores may then be mixed into the earth. Propagation by spores is little understood, however. (See [page 24].)
Mustard (Brassica or Sinapis species).
Propagated by seeds.
Mutisia. Compositæ.
Seeds. Layers and cuttings of growing wood, those of the tender species in bottom heat.
Mygindia, Rhacoma. Celastrineæ.
Seeds. Cuttings of firm shoots under glass.