Time of sowing

The seeds of many native grass species will germinate over a wide range of temperatures, although the optimum is usually higher for warm season than for cool season or year-long green species. Optimal temperature requirements for germination are given in the Species quick reference. The choice of sowing time for each species is therefore determined more by the probability of successful establishment than by opportunities for germination. For example, seedlings of warm season grasses will have the best chance of germinating after late autumn rains on the Northern Tablelands but they will almost certainly not survive the winter because of frost. These species are therefore sown in late summer. Similarly, seeds of cool season or year-long green species will readily germinate following suitable rain in the late spring, but are unlikely to survive the first summer. These species are best sown in autumn. On the other hand, early spring sowing has proved to be satisfactory for warm season species in other environments.

A further consideration for selecting a sowing time is the likely germination time of weeds, particularly annual grasses and broadleaf species. If the soil seedbank of such species is at all significant, then a sowing time when the weeds are less likely to germinate is important, unless steps are taken to control them.

Choice of sowing time to a large extent depends on the rainfall distribution at the site and the species to be sown. In general terms, warm season species are best sown in the early autumn providing frost-susceptible seedlings can become well established before the onset of winter. In summer dominant rainfall areas spring sowings have given better results. On the other hand, frost tolerant cool season and year-long green native grasses are best sown in the late autumn when the major germination of the competing weeds has already occurred.