Hi, as it takes several years for them to get to flowering size, I would just replant the whole lot, I think they also look more natural that way, rather than individual plants in regimented rows, Derek.

yes I usually plant them in a cluster and then the large one flowers and the smaller ones leaf up, grow bigger and then in a few years time flower.

This only works for my Darwin Tulips. The large bulbs produce larger flowers, the smaller bulbs, smaller flowers. Combined they make a striking display. Forcing apart 'mother & daughter' bulbs will create a wound. The mother bulb will die off naturally in a few years as the babies spread outward. None of the hybrids ever returned the next year.

I have many species tulips as well has named varieties and many of those come back year on year. I think you must have been unlucky.

SBG - Which of your hybrids have come back? Do they produce offsets? Are the offsets true to parent? To me, they aren't worth the time or money, just for one season. I'd like to know which of you hybrids have returned so I can get some. thanks.

Uncle Tom, Early harvest, and unnamed one that I inherited in the garden. I have a couple of the fosteriana hybrids but lost the names over time. sometimes they are called emperor tulips.
the parrot types come back true too and originally planted in 5's there were 8=10 flowers this spring.

the offsets are genetically identical as they are a method of vegetative reproduction and are therefore clones. sometimes there is some genetic changes in the bulb but on the whole not.