I keep my nerines in a cold gh allyear round, to chilly here to grow outside
, I feed in the spring with high potash feed and keep them well watered.
I used a well drained compost and clay pots, they flower in october
hope this helps
by the way mine are the pink N. bowdenii, there are other varieties that need more care I think, saw some at the Guernsey lily festival, they were in a gh and clay pots which is why I do.

I guess you gave them a high nitrogen feed which will give you lots of leaves and few flowers. Normally about now you would get few if any leaves, though this unusual year I've had both at once, though the leaves were pretty small. You could try giving them a high potash feed and then leaving them alone. In a mild winter and a sheltered spot they can stay outside as ours do (SW facing corner in the SW of the country) Otherwise protect from the worst of the winter. I do nothing to mine except one potash feed when the leaves are there and this year we had 13 flowers in a pot smaller than yours. They have been in the same pot and compost for about 10 years. (No, I think they were repotted once)Lets hope they flower next year anyway, only don't give them any more nitrogen for a long time! And if they still don't flower don't give up, they will when they get hungrier.

Nerines flower in late summer and foliage appears in spring. so yes large leaves are unusual but the weather has been mild.
I'd leave them alone and let nature sort them out.

I had to google what Nerine leaves look like as I pay no attention to them until the burst of vibrant pink flowers comes out in early Sept through to November depending on weather. As per the above I would leave them as is. I would guess that with the multitude of leaves feeding the plant that you may get a bumper amount of flowers next year, though it may also dwarf/limit them!

I have had Nerines for years and they always over-winter outside in the garden and have always survived. We are in the East Anglian region and it's not the warmest spot! They survived the really hard winter we had a few years back when the ground was frozen for weeks. Are they not another plant that likes to be fairly 'pot-bound'? Mine were all jammed into a small space in the garden edge when I first moved so had little room. Now they have been moved and spread out into various places and haven't flowered as well this year.

Mine must certainly be pot bound by now and they flower their hearts out.

thanks everyone

Solid mostly yellow clay here which is why I chose pots for mine, I thought they would be happier in well drained soil