quote My OH is pressing me to put some of my allotment space aside to
grow
flowers to cut for the house. Which is fair enough but if I cut
flowers such as gladioli will they regrow next year from the same
bulbs or be too weakened to recover. Is there a trick to cutting
flowers in such a way that they can reliably grow from year to year?

Cutting the flowers will not weaken them, in fact may well help them as
then all the plants energy will go into building new bulbs and corms
for the next year making them more likely to flower. Proffessional bulb
growers do not let them flower, or at least cut the flowers off as soon
as they open, which is why there is a flower parade at Spalding each
year, they use the cut of blooms to decorate the floats.

Mike