Gladiolus hybrids... Dig 6 or 8 weeks after bloom or when frost kills foliage. Cure 2 to 3 weeks in a dry, well-ventilated area at about 60 - 70ð F. Remove old corm with a twist of the wrist and all the little cormels. Store in labeled paper or mesh bags in your basement.

I doubt glad corms are winter hardy in your zone - either in the ground or in pots. If they're special, they might be worth trying to save over the winter. I've tried a few times largely with disappointing success - mold happens and some viable corms put out foliage the next season but either sad or no blooms at all. Others have had different and better results.

If and when I want to plant glads, I start with fresh corms every season; theyre inexpensive and readily available just about anywhere in single or mixed colors. Gives you a chance to change out your color schemes.

If they mold, your storage area must be too moist or the bulbs weren't cured long enough.

That given, I find that thrips seems to inevitably occur after a couple years...so given that, I have learned it's mostly best to buy new corms too, though with a mild winter, they can overwinter here (just not dependably).