Fen Management Handbook - Scottish Natural Heritage

Experience has shown that the most suitable time to do this is in
early spring when the ground is moist and warming. Establishment is
then quick and does not suffer from the movements caused by frost
heave encountered by attempts to establish vegetation in the autumn.
Collection of material is best done locally and requires permission
from the landowner, and from the relevant conservation body if the
site is designated. Suitable areas for collection should have a similar
topography and water source as the area to be seeded.
9.9.8 Hay
Strewing hay is a relatively cheap method of establishing species-rich vegetation.
Creating suitable environmental conditions on the receptor site, the viability and
correct treatment of the hay seed source are key ingredients for success. It is best
to take several crops from the donor site through the season to include species
which flower at different times, although many flowers will not set seed if cut
back frequently, so two cuts is usually the practical limit. No special machinery
is required, but generally the smaller and lighter the better to reduce impact on
vegetation.
Getting the best results from hay-strewn seed
Using the hay immediately allows seeds to germinate immediately.
If left, the seeds can become dormant, after which it can be hard to
stimulate germination. Donor sites for hay should have similar soil and
water conditions to the creation site. Take care that the sward does not
contain invasive species which may become a nuisance on the created
fen.
The proportion of viable seed is usually higher in green hay (i.e. freshly
cut and not fully dried), provided the time between harvesting and
spreading is less than two hours. The logistics of moving green bales
will determine how fresh the bales are: if moved by hand, green hay
bales can be very heavy. Dry hay yields fewer seeds, but will not rot so
quickly or kill seeds through rising temperatures in decomposing hay.
Small round mini-bales are easy to handle and can easily be rolled back out on the
fen creation site. A mini-baler also allows haymaking in wetter areas containing a
larger range of wetland species, where larger machinery would get stuck or cause
damage. Big round bales are also spread by rolling out. Alternatively unbound
bales can be strewn with a muck spreader.
207