Garden lacking colour-what to plant for autumn?

My 2year old ggd asked her mum for balloons to be planted in their garden

Thank you, everyone. There are some great ideas here. I'm going to write down all the suggestions - I even need to find out what some of them are as I don't know the names. Then I'll see what I can find. I managed to get a nice Golden Rod this morning at our local market so that's a start.

Just got back from lunch at the garden centre. They have so much in full bloom! You could start over with another Summer. Even trays of pansies and violas. Was sorely tempted but resisted with holidays coming up.

Check out euonymua alatus. Red perennial.

My favourite plant is Golden Oregano (marjoram). Pale lime yellow leaves all year. Small flowers early summer. Cut it down Sept/Oct and it produces new leaves which stay bright until the next spring. AND you can cook.with it!

Gonegirl... I plucked up courage and did mine. Two days later they started to shoot, and they are now flowering again... a mere three weeks later.

Right sue. Will get on with it in the morning.

To late for this year but, Dahlia. Colour from July to first frost

My buddleia adds some colour in August. The cotoneaster horizontalis will soon change to dark red. The crab apples will ripen to orange. There is a second flowering of Warm Welcome roses.

Crocosmia comes out soon and looks like fireworks until around November.