We have established that the flowers of grape hyacinths are edible, but there seems to be a lot of confusion in general about whether or not Muscari is toxic to humans or animals. In particular, concerns revolve around grape hyacinth bulbs. Here is the page for grape hyacinth from the ASPCA. It says “non-toxic to dogs, non-toxic to cats.” Note that the listing is specifically for Muscari armeniacum. On the other hand, charity Plants for a Future says, “The bulb is poisonous[4]. It contains a substance called comisic acid, which is said to act like saponin[4]. Although poisonous, saponins are poorly absorbed by the human body and so most pass through without harm.” This page is specifically for Muscari neglectum. So, it sounds like either way, Muscari poisoning is not a major concern. Still, to be on the safe side, we recommend that you do not ingest any part of the bulb, and likewise keep your pets away from grape hyacinth bulbs.