For the past 4 years I have planted a package of 20 snowdrops sold by a local nursery, By now I thought I'd have them blooming and naturalizing but they seem to have disappeared. I see 2-4 and they are spindly and not all bloom. Squirrels are said not to like them. Any ideas? Thanks.
Success with bulbs can sometimes be difficult and this is frustrating. It depends on the weather, how deeply the bulbs are planted, if they had time to root after planting, poor growing conditions, etc.
Here are some thoughts. Bulbs need at least 6-8 hours of sun. Perhaps the area is too shady, however, these bulbs often perform well under trees. Bulbs need good drainage and our soils have been saturated from excessive rain. Perhaps they have rotted. You will have to dig in the area to determine the issue. Hopefully the bulbs were in good condition when you planted them and not mushy. It is also possible they may have been dug up by squirrels, if they are in the area. However, they are not known to eat them.
Here are links for more information https://www.uvm.edu/pss/ppp/pubs/oh21bulbs.htm