this looks typical of thrip damage. [possibly viral but more likely thrip] Its a small slime black insect that sucks the sap . the damage probably happened more than 6 weeks ago. The plants will be ok next year provided they dont get attacked again. It is so disappointing for you Womble.

Agree, Gladiolus thrips - there should be a spray available to treat for this, but when the plants are over, remove affected foliage (you're supposed to burn it) and when you lift the corms, make sure you store them somewhere very cool, but frost free - this pest can overwinter on the corms, and will weaken them if not stored properly.

meant to type slim insect. :o)

Thanks. Whats the best way to storing them? I dugged a load up last year but i hadnt stored them properly and they rotted. These were my replacements.

Bit of a performance, frankly, and I never bother, just buy new each year. You're supposed to dig them up in September, remove any topgrowth hanging about, remove the corm beneath the new corm formed at the top, plus remove any small cormlets round it, then clean them, leave to dry somewhere airy, then store in a frost free, dry place. I used to put mine in dry silver sand in trays.

I don't bother to dig them up either, i leave mine in the ground :-/

Trouble is, these ones have got thrips, so they can't be left - either dumped or stored effectively is the only way to go.

Didn't realise it's a killer, it'll just infect the rest then, shame.

Not a killer, but will affect next year if not dealt with properly with this lot.

Hmm, interesting.

Thanks Bamboo. i guess its worth storing them and hoping they survive this time unlike the last batch. do you know if this affects any other plants?

Other plants can get thrips, but this one's specifically gladiolus thrips.