Q.why are my glads not growing?
I have a medium size garden with tulips growing so, after they bloom, I plant my glads. The first few years i did this they were wonderful but the last couple of years not so much. I planted over 100 and I may get half that many flowers. I even bought some new bulbs this year — my flowers are small and not many of them.
Certified GKH Gardening Expert
Gladiola are not hardy in zone 5. (hardy in zones 8-11) In zones 6 and 7 they return if mulched heavily. So that might account for many of your losses. Is your soil well-drained? If not, the corms may have rotted. Are they in a sunny location? They may be overcrowded.
This fall, try digging up the corms and overwintering the ones that look healthy. Replant in spring with fertilizer added to planting trnch. Instructions are below: