Too late, yes - they should be fed in April and June, no later. But many people don't feed their roses, and they flower pretty well anyway... If the soil is nice and damp, you could apply a mulch of something organic, like good garden compost or composted animal manure. This will steadily break down and add nutrients to the soil, enabling the plants to take what they need when they need it.

I don't think it's too late to feed but I wouldn't do so from August . At this time of year I'd suggest liquid tomato feed for the roses to absorb nutrients quickly.

Well, there's a general rule - you don't feed any permanent plant after the longest day, which is actually in June - plants are already getting signals that day length is shortening, and will be changing their habits a bit over time from then on in preparation for autumn and winter.

It's fine to keep feeding annuals or plants that will be chucked at the end of the season.

I have been feeding mine every month since June and also sparaying my roses every month and they are looking great been many blooms and now with the rain been deadheading a lot.

I just realised that other people may not be using a specialist rose food for their roses (Toprose or similar), and my original answer assumed that was what you meant.

I'd always recommend a specialist rose food, but if you want to give them a quick shot of something ordinary like Miracle Gro (the blue powder in the box, mixed up) now, that won't do any harm, the effects don't last long, unlike proper rose food.

We have not specifically fed any of our roses for 20 years. They flower.

yea, I agree, don't stop 'em flowering if they're not fed.

Thanks everyone. Appreciate your suggestions.