I am in Toronto. Soil is clay. Garden is full shade. Looking for hardy evergreen fern that grows up to 3’ tall to plant in between euonymus. Also would consider growing them in large fabric planters (to avoid being trampled by dogs).
Previously that bed was overrun with gout weed. I think the goutweed killed hostas that were there. I tilled it up a couple of years ago and has so far grown back very minimally. Any recommendations to prevent goutweed spread are welcome.
Evergreen Fern
If you choose to go the route of planting directly in the soil, you should consider amending it with organic material to improve its overall health and make it more suitable for the evergreen of your choosing. Growing evergreen ferns in planters not only has the advantage of avoiding having the plants trampled by dogs, but also for you to fill those planters with a suitable soil mix.
Finding an evergreen fern is challenging, however you could consider a Japanese shield fern (Dryopteris erythrosora).
This species is sometimes named Autumn fern because of the “fall-like” bronze colour of the developing fronds and later fall colour. It grows up to 2′ and can be massed as a groundcover. This species will remain evergreen in protected locations. Other options are listed in Hardy Garden Ferns: A Toronto Master Gardeners Guide.
Goutweed
You had also asked about how to avoid the spread of goutweed. It will take time and patience. You will not be able to use the chemical control method using banned pesticides in Ontario: https://www.invasive.org/weedcd/pdfs/wgw/goutweed.pdf.
Eradicating goutweed takes time and patience. In order to get rid of it properly, you need to follow its root and completely unearth it. This is easier after a good rain. Please note that just 5mm of root left will create a new plant. Of course this job is easier if you do not have other plants in the area. As it looks like nothing else is yet planted in the area, you could also dig down about 2 feet then sift the soil to remove all the roots and rhizomes. Rhizomes should be bagged and disposed of to prevent reestablishment.
Happy planting!