Recommendation is to plant in spring rather than fall, either directly in the ground or into pots to be planted out once they've germinated.

They should be treated as annuals and sown in October to over winter, then plant out April.

Sorry, SG, what do you mean by ' they should be treated as annuals'?
Diana: I forgot to ask whether you're sowing L. latifolius or L. nervosa or some other variety. If its L. nervosa, they germinate better if you nick the seed before planting. Info regarding planting time for these given in my first answer sourced from RHS (Royal Horticultural Society). You may find they don't flower till the year after though, but sometimes you're lucky.

or in autumn as the plant sows its own seeds from their pods in autumn.

i vaguely remember a member saying perenial peas are a problem in some states.