Can you thin them out when they are crowded. They are outside and I want to thin them. They have already flowered… still more buds on some.
Yes, you can thin the bulbs while they are actively growing if you're gentle.
Dig under the whole clump, tease individual bulbs apart and then replant. Be careful not to damage the leaves (don't trim them) as they are producing the food for the plants (photosynthesis).
If these are in full sun you might want to provide some shade for a week or so while they settle back in.