Richard Wright wrote:
In my area of Sydney (inner) daffodils mostly come up non-flowering in
the second season after planting.

Does anybody know whether the bulbs ever produce flowers in a season
after one in which they have been non-flowering? I suspect that once
they have been non-flowering then they will never flower again.

Has anybody any experience (i.e. experience as distinct from
anecdotes) with how to stop them going into a non-flowering condition.

I did read about digging them up in autumn and putting them in the
fridge for a couple of months. That didn't work for me.

Insufficient nutrient availability is probably the main reason for poor
flowering in Daff's. Start feeding them with a high potassium
fertiliser/commercial bulb food. Normally you'd do this after flowering
until they go dormant. I wouldn't have thought Sydney winters were warm
enough to necessitate putting them in the fridge.