I'm still planning the layout of my mixed borders. I have a normal small
suburban garden -- grass surrounded by borders on three sides.

The rear border will be mostly summer perennials and cottage-type annuals in
pink and blue pastel shades. However, the side borders I'd like to be more
for autumn with rudbeckia, crocosmia, echinacea, autumn chrysanths, asters
and such like.

My question is -- is it a good idea to have separate (but adjacent)
borders -- one for autumn and one for summer, in totally different
contrasting colours? Or is it better to incorporate the autumn plants in
with everything else?

The summer pastel flowers will probably still be in bloom when the autumn
fiery shades come out, and I'm worried that everything will clash and look
awful. The garden is not very large so all the borders are seen together.

Thanks.