Check out my White Walnut thread. Every single one of those nuts germinated and now are beautiful seedlings. Here is what I would suggest with your walnuts from last year, crack open a few of them and observe, I'm guessing they are dehydrated and dead. Try again this year, collect the nuts, remove the husks. If you must use the refrigerator mix the clean nuts with equal parts damp sand, store in fridge 'till March and then sow.

Sam, given that the OP is in z4b, is there any reason for the fridge. Why not sow them and overwinter outdoors?

The reason I don’t - the countless critters that can eat them.

If I want to direct sow any kind of nut, be a walnut, Hickory, oak…Aesculus...

The amount of effort I have to go through to barricade it to keep all the critters out, it’s easier just to stratify in the fridge and start it in a pot, then stick it in the ground when it’s big enough of a seedling to no longer need the nut for energy.

LOL!! I just let the critters do the planting for me! Every spring I go through the garden - and all my containers - and dig or pull tree seedlings that have germinated from nuts "planted" by the squirrels.....horse chestnuts, oaks, walnuts. It is their winter stash they have buried and then forgotten about :-) Most I don't keep. Have no need for a forest of nut trees.

Fortunately, the trees in their 2nd seeding produced enough to plant despite high winds that mucked up the young ones. Looking forward to next year and will stratify properly. NOTE: Should husks be removed for stratifying? Hard to remove when green. Should I let them rot a little? Thanks to all of you who try to help others.

Are you saying your walnuts are green? I don't know about Black walnuts, but English walnuts split and the nut falls out of its own accord when ripe. If they're green they're not ripe.

The husks are green when they drop from the tree. Ideally I'd pick up those that freshly drop rather than picking off the tree. Remove the husks but wear rubber gloves. Decades ago I harvested a bunch for eating (great tasting) and the rubber gloves I used for de-husking are still stained despite being used over the years in some harsh cleansers.

tj

On the walnut trees I'm familiar with the green husks fall and split open and the nuts fall out. I've never needed to dehusk ripe nuts. They're just lying on the ground. Green walnuts picked in June before the nutshells harden can be pickled whole. A messy job. You have stained fingers for days.

rare thin shelled black walnut

Never heard of that but would like to know more. Show us a pic.

Concerning Juglans nigra, certain years they are incredibly productive. In October they can be carted by the wheelbarrow to a low spot in the lane. Run over them for a week or two and the husks desinegrate and pick out the clean nuts.

HERE is one of several videos showing how to clean black walnuts.

Yes please share more about the thin shelled black walnut. I am a research working on black walnut improvement and need to know! Thanks