I think you may be excessively concerned about freezing in winter. The feeder roots go where the action is and will always come up to the surface if the mulch isn't something like pine needles or fresh wood where they just cannot function. Go into the woods right now and push aside the leaves and see how many fine feeder roots various species are sending right to the surface. If you don't think there is enough root established below to make it through winter insulate them with some half rotted oak leaves or pine needles in the fall. Sounds to me like you should be very pleased by their growth. Paw paws tend to be quite sluggish for their first few years.

Maple trees are like black walnuts in the regard that they are alleopathic (self weeding), which may account for some of the problem growing certain plants under them, especially grass. They are also very surface rooted, water and nutrient hogs, and the roots will grow up into any layer of mulch or soil you put over the feeder roots. Also, the feeder roots are not really close to the tree, where the huge support roots tend to stick out above the ground. They are at and beyond the drip line (where the ends of the branches are--if you read any bag of tree fertilizer directions it always tells you to put tree food around the tree at the drip line, not close to the trunk). If you plant fairly close to the trunk you'll avoid the fine feeder root problem. I've never had a problem digging there. I've had hostas growing inside the drip line of my big Norway Chrimson King maple for some 25 years. They don't get huge, as they would in a bed with plenty of running room, but they hold their own and look good. I removed the grass a long time ago around this old tree as it was impossible to mow around it due to the huge surface roots, and let the native violets come up around it as ground cover with some ajuga. Recently, in addition to the hostas, a colony of rudbeckias has moved in there, and they are flourishing. There are also coral bells, nandinas, dwarf crape myrtles, ground cover sedums, French strawberries, a forsythia, an old dogwood. clematis, and a mixed perennial bed within reach of those greedy roots that are all thriving. So you see, it is possible to grow things under a maple, if you pick the right plants. I give supplimental water in the hot dry summer months but I never fertilize anything under there. Now, a giant hackberry in the woods garden......that is another story. The jury is still out on that one but it appears even more alleopathic than the black walnut with roots even more aggressive than the maple and its thick canopy prevents rain from reaching the ground. Time will tell on the new bed I'm trying in this area. I know it doesn't like veriegated kerria under there, I'm going to have to move this little shrub that has been struggling for the last few years in its shade. It isn't going to overcome the odds.

i removed 9 ash trees this year.. due to EAB .... i am surprised the plague hasnt hit your area ... ash was sold to me as a good tree to garden under .... BUT there are at least two types of ash ... white ash good .. green ash not good in my opinion ... under any large tree .... i would recommend digging a hole... and using that soil to plant the hosta ... any amendments will bring the tree directly to the planting hole .... versus amending an entire bed ... you dont mention how big the tree is ... a 2.5 foot bed around a foot wide tree... is not enough ... to get out to 'good soil' .... i would never fertilize.. just the hosta or its hole.. again.. the tree will come into the hole to steal the food or amendments ... i would broadcast all water ... versus watering just the hosta.. for the same reasons .... i would suggest you get a proper ID of what ash you have... and also that you contact your local extension office to find out if the ash borer is in your area ... and learn to ID the bug and its telltale holes ... personally .. having had to destroy mine this year .... i would suggest you NOT get too attached to the thing .... because i dont think it will be around all that long... short of spending hundreds of dollars to treat the thing ... good luck ken Here is a link that might be useful: ken

It is very disturbing to dig up a failing hosta and find maple roots that resemble the straw stuff used in hanging plant baskets, a few hosta roots and very little soil. I have never used spinout bags, but from read in this forumm over the recent years it's the way you might need to go if you want your hostas in the ground. It is equally disturbing digging a hosta up and finding no competing roots but only a few hosta roots that weren't gnawed off the crown by a vole. I think if I had a good "vole-cat" I would name it Elmer Fudd and tell it to go after those "wascally Woles"!Les Les