Through our work, we are in touch with meadows all over England, and keep in touch with customer projects of all kinds. The intense hot and dry year, has caused most plants to finish flowering and go to seed. In aesthetic terms, they've gone brown and dead-looking, as has the grass in meadows.a
Not all wildflowers have struggled with these conditions - some are only just approaching flowering and being their best. Some can now be revived to flower again in the late summer and autumn, by cutting them back. This post explains what you can do, to revive a meadow/border/container in August.
The following wildflowers can and should be cut back to 2-3inches (i.e. short) if running to seed or dead-looking. Remove the cuttings, and water heavily. Then leave and watch nature bounce-back for a second-flush of flowers into late-summer and autumn.
Birds Foot Trefoil
Red Campion (will sometimes re-flower in Autumn if cut. If not, it will help it for next year)
Ragged Robin (see comments for Red Campion)
Yellow Flag Iris
These varieties should not be cut back in August, as they are late flowering or won't re-flower this year. Cut back in autumn though.
Field Scabious (although they might come back if you do, and will cope if you have to cut your meadow)
Cornflower - because it is an annual, and it won't recover.
Poppy - because it's an annual and it's flowering period is over.
Harebell (should regenerate after rain)
Devil's Bit Scabious (see Field Scabious comments)