Tim you are correct, the foliage of I. 'Pixie' behaves well in my semp beds, or anywhere else. The foliage is so small it seems to just fade away. As soon as it is brown I remove it.
Note to self, do not buy/plant:
1. Allium 'Hair'
2. Ornithogalum umbellatum
The little white blooms are so sweet.
To late, I already have Triteleia laxa 'Queen Fabiola' (Brodiaea 'Queen Fabiola' ) But I love it, Iv'e had it for several years and have not had problems with it. When I see tiny green grass like leaves appearing where I don't want it I just pull them up. So far that has worked. It seems to be very happy in the semp bed.
And Arum italicum. Connie is correct, once you have it, you will have it until you die. But I do love the leaves. I would never put this one in my semp beds.