Did you build on top of an old dump site? My best guess........

Suzy,
This is not uncommon - in the "good old days" it seems like most homes were surrounded by fences-and any area on the other side of these fences was "the dump". These bits and pieces of glass were probably buried many years ago, and through the process of our winter freezing and thawing (I'm also in zone 4-Minn.), and all this rain we have been receiving, these pieces of glass work themselves up to the top of the soil. After every rain I can go out and find more pieces of glass in what is now my gardens-but used to be the family dump! Same as the rocks in our farmers fields, they appear every spring also-just like magic!! Hope this helps with your mystery.

I have found a lot of stuff in the soil in my so. mpls yard. The back yard seems to have been a repository for lots of stuff. Ive found pieces of what looks like charcoal, rusty locks, nails, marbles, bits of broken dishes, lots of broken glass...even the porcelain leg of a doll and a piece of a metal toy that looked like a circus lion on wheels and old glass bottles. it's an adventure I tell ya! Just take care, (and maybe think about a tetanus shot if you're not up to date)!
suzy

I'm up to date on my tetanus :-) The gardens are in my backyard....which has been a backyard since the 1920's....so no dump. Here's why I am confused....I killed the sod and turned the garden by hand. Then I spent a week sitting out in that pile of dirt breaking the dead sod down by hand....and adding more dirt & compost. During that time....I didn't find one piece of glass....not one (only one marble). I have been pulling weeds by hand and have only tilled once. The glass is found laying atop the soil. Found more again today.

I did think that maybe it was the recycling guys who smash the recycled glass into their trucks.....but when I went out to see if there was glass in the alley, found there was none. Oh well, I guess I have a little glass fairy :-) Maybe it will keep some of those slugs at bay.

My house is roughly the same age, and it's been my understanding that it was common practice for a family to use the back portion of their own lots to bury refuse from their own homes. Wonder if removing the sod and disturbing the soil hasn't made it easier for stuff to come up to the surface. Now that I've been working the soil, "stuff" doesn't seem to "pop up" as it did in the beginning. (I kind of miss it-lol)
suzy

I understand how frost heaves to the surface- and rain can wash away soil and expose items- but this sounds like new glass, not aged- laying on top of the soil.....
Kritters who gather shiny objects usually protect them better then laying them out- exposed.
Could it be a "hepful" neighbor cleaning up after the recycle guys and sweeping the "dirt under the rug"? Is there any in the lawn or paths? Any in/on the fence? Any neighbors having this problem? Hhhmmmm...
Please keep us posted with your sleuthing-
Julie

It does seem to be newer glass, but I could be wrong. I don't think it is a neighbor...because the garden is in kind of an out of the way spot....and behind a fence. My neighbors are pretty responsible/friedly too. I have not seen any in the lawn or on the sidewalk/paths. The thing that makes me shake my head is that is appears on the surface of the newly dug garden....but also on top of a layer of wood chip mulch in an older garden. I'm new to gardening, so I have been watching these beds like a hawk. At any rate, I have started a little collection pile. Lol....this one has me laughing and shaking my head. I just wish it was something a little more interesting/valuable that was popping up.