gallicas list includes a few plants that are really sun plants ... which means.. that her trees are limbed up.. to provide a canopy ... but allow a lot of ambient light ... defining shade is near impossible ... what will grow in any given spot depends on whether it can derive enough energy to convert into food ... and under trees that usually begins with the canopy ... i grow hosta ... a LOT of hosta.. i have been in hundreds of hosta gardens.. all are technically 'shade' .. some gardens are so dark.. you need a flashlight ... and eventually even the shade plants start to fail ... e.g. under a norway the canopy is so thick that barely any light gets under it ... [though that example is complicated by the norways aggressive root structure which is only dealt with by sudden death, with a chainsaw ] ... other 'shade' gardens ... are so bright.. you still need your sunglasses ... the point.. is that all you can do.. is try various things ... and see what will grow under your given trees ... back to gallica ... note they mention roses.. but SPECIES roses... which are much more tolerant.. since most only bloom once per year.. and otherwise are just a big green leafy bush.. which can generate the energy to live/thrive ... if you were to try a hybrid tee rose.. which blooms repeated over the season .. with minimal leaves[comparatively speaking] .. the plant will probably live .. but your flower production.. if any.. will suffer ... if one could not dig holes.. and garden under trees.. then there would be no hosta gardens.. nor shade gardeners .. eh ... if you are going to stay in this house a long time.. and you really think you will be encouraging the gardening bug.. you really ought to start by considering whether you should invest in raising the canopy of your trees.. and perhaps.. even getting rid of trees that will not cooperate ... it is much easier to have tree work done.. BEFORE you build the garden.. rather than later ... [this is the hosta lovers biggest regret, in hindsight] if in fact you do have to remove a tree.. simply replace it with a better tree.. mother earth.. net zero ... no guilt ... good luck ken

I am thinking it needs much more sun.... even in my arid conditions it needs some sun.

I'm in Metro Detroit, and so far, the squirrels have eaten all the Sweet Woodruff I planted for three years. They seemed to leave it alone last year, but I'm honestly not sure if the stuff grew ANY over the summer. I found lots of Periwinkle (I assume you mean vinca minor?) taking over the garden here. It created a solid mat of greenery around the existing hostas and attached itself to all rocks and shrubbery in its path. Since the garden had only been neglected a couple years, I don't know what could happen long term. It's too vigorous for me to want in most of my hosta beds. For tall hostas, I actually like Canadian Wild Ginger as an underplanting. For small hostas, I have some Buglewood and Dwarf Crested Iris that survive just fine.

Just bumping this down