muscari , grape hyacinth help?

Can anyone tell me if and when is best to divide Muscari. Also can I trim the foliage down and when is best ?

 

Muscari are pretty well indestructable. Wait 'till after flowering then lift clumps and divide 'in the green' as the bulbs are much easier to find when they still have leaf attached. Replant immediately. Otherwise wait untill they are dormant, lift clumps and separate out on a garden sieve.

They do self seed freely so any patch you clear will have them return fairly quickly. Bit of a devil to eliminate entirely.

With most bulbs it's better to wait untill the leavs die back naturally as the leaf feeds the bulb for the coming year's flower but with Muscari it would be safe to cut them back once the leaves start to go brown.

 

I've found the best way to divide them is to dig up a clump and drop it in the bin.