Pleurocarpous mosses will respond to fragmentation techniques much faster than acrocarpous mosses will. By nature of their growth habit and response to moisture, pleurocarps will respond with new growth within 3 months if moisture is sufficient. Their stems will continually branch and lengthen making them superior for carpeting.
Any part of a pleuro is viable for regeneration. The larger the fragment the more quickly it will recover. Very small fragments (less than 1/4 inch) are likely to revert to a younger state of maturity called protonema. This fragile state is where the moss acts like an alga, and grows more like a film on the surface. Protonemal mosses are more likely to perish if they become dry and may take many weeks before developing into a mature gametophyte (fully developed moss with leaves).
Acrocarpous mosses that have been fragmented may need 6 months or more to anchor themselves and another 12 months to multiply. Since acrocarps spread by the growth of new individual upright stems, the pace of their spreading is slower. Since most acrocarpous mosses require periodic dry periods, they cannot stay in a growth mode everyday like pleurocarps.
The growing tips or outer layers of Acrocarps are more readily regenerated than the older lower parts of the stem. When fragmenting acro’s, be sure to crumble or cut the growing tips with scissors. Simply separating the stems will leave them less able to orient themselves upright and create new rhizoids.
Fragmentation should be done when the moss is dry. In their desiccated state, they have prepared themselves for possible damage, storing a small amount of protein that can be used to repair any cellular damage once moisture returns.
Spread the fragments onto a prepared and lightly scratched soil, water enough to wet the top inch of soil and then press them firmly, re-compacting the soils surface. This will provide good contact with as much surface area of the fragments and promote rhizoid formation. Compacting also acts to trap the fragments between soil particles keeping them from blowing away. Water the fragments 1 to 4 times a day depending on the conditions and occasionally walk on them to keep their contact with the soil.
Divisions can be held in place by netting, toothpicks or greening pins. Toothpicks can be inserted at opposite angles to work in unison with one another. Acrocarps are better held in place with netting. Securing moss divisions in place is useful for areas with water run-off or gusty winds. Securing also prevents unnecessary disturbance which can disrupt rhizome development.