i would be more surprised.. if those werent all viable thistle seed.. and not what you call SHELLS ... ive watched birds eat thistle whole.. i never saw one sitting there cracking them open like tiny peanuts ...

i only hung bird feeders over my garden for one year.. because.. i found.. they waste a lot of seed... and too much of it sprouted in my garden beds..

so i started hanging then off the gutters along a huge window on the driveway ... seed doesnt sprout on concrete.. lol ...AND!!!!! .. birds could actually find it on the ground... to eat it there ... instaed of being hidden you your plants ...

actually.. im surprised you dont have a mouse or vermin probably in there ..

whatevs.. move the plant if you want.. i dont know why you need to bring in bagged soil... cant you just find some native soil back behind the garage to move in the hole???

ken

ps: and then i moved out of suburbia to the country.. and i quit feeding the birds.. why waste money on animals that can actually feed themselves.. and i mean really.. there are like billions of them out here ... they ought to be feeding me ..wait... did i ever mention we have dad .... 2 moms.. and 19!!!! babe turkeys that lurk in the yard as they stroll around the area ...

It's been there several years and I have never had anything sprouting from it. I guess that's why it was am inch thick. As far as finding soil that won't work unless not to mention pulling grass up. I like keeping the gold finches and blue birds around, I spend most of my time in my yard when I'm home so it's worth it. I haven't had turkeys but I did have a mom duck and about 6 babies find the way into yard. I'm guessing for my water garden/small pond.