Planting containers in July

[Michaelmonstera]

what could I plant in pots now that would last into September/October?

Roses.

Bedding Asters, Cosmos, marigolds.

Thank you

Wallflower, Bowles Mauve - they practically flower all-year round.
Japanese anemone
Dahila

Argyranthemum Pink Halo. Abundance of flowers, just dead head regularly and they’ll keep going until the first frosts.

Osteospermum, salvia 'nachvtlinder or 'amistad'

Geraniums, anemone, aster, fuscia, many really as long as you keep deadheading!

So many good suggestions. I would have a garden full of sedum autumn Joy, as it looks good for most of the year, and the dead flowers can stay on the plant for most of the winter giving structure.

Ooh yes to the sedums! I would love lots more sempervivums too in all different leaf colours, plus the bees and other pollinators adore them.

Rudbeckia, planning to plant three in a large pot later today which I bought from Waitrose Garden at discounted price

Nasturtiums, which will cascade abundantly and complement the autumn colours

Chrysanthemums

I have gone for some rudbeckia for the pots in my front garden