Beebombs need no gardening skill and can be scattered straight onto open ground at any time of the year.
Once scattered, Beebombs just need lots of water, sun and time. Wildflowers are hardy and adaptable but slow growers. This means that they can be out-competed by faster growing grasses and perennial weeds at the critical early stages, so straight onto soil is best if possible.
The soil will help your Beebombs germinate and the clay will protect them as they dissipate.
Lots of sun and rain is of course important, as is time.