Tulips

I have found that it makes no difference whether I dig them up or leave them in the ground. The only ones I remove are the ones shallowly planted in pots which the squirrels are likely to eat.

I leave them to die back, then continue to replant in the autumn. Mine tend to dwindle each year.

Leave them they will start doubling up over the years and you will be rewarded by many more.

We went to a lot of trouble last summer with the tulips we had in pots.
We had lots, so we dried them off in the sun but still a percentage of them were attacked with mould.
The ones that were healthy we replanted and had a good show this spring.
I have to say in the past they dwindled to nothing, so I will just have to wait until next spring to see if I get the same show, I suppose!

Feed them after they flower and before the leaves die back, then leave them. It helps if they are planted relatively deep.