Are there any flowers, shrubs, grasses, ferns, etc. that can grow under Norway Maples? I’ve 2 in back garden which is surrounded on 2 sides by 6′ fence = total shade. No flowers survive, some Hostas do survive but even some shade Hostas don’t. 1 in front garden, grass underneath with flowers around. Grass is spotty but flowers are OK -they are further away from the tree but still within the drip line. Front yard has a fair amount of sun but still a lot of shade during the day. Both gardens have water sprinkler system installed.
Thank you very much for contacting the Toronto Master Gardeners. You are not alone with the struggle to grow something (anything!) in the dense shade of a Norway maple (Acer platanoides). We receive frequent questions like this and I will start by referring you to a previous entry on our site that describes the issue and some suggestions well. https://www.torontomastergardeners.ca/askagardener/growing-under-a-norway-maple/
Thinning the tree canopy may sound extreme but is the best way to increase light penetration and help understory plants to thrive. This can be done in the winter and should be in consultation with an arborist and the above link provides information about how to locate an arborist near you.
The Missouri Botanical Garden and Landscape Ontario have published a list of plants amenable to deep shade and I have attached the links below.
https://landscapeontario.com/perennials-for-shade
One other thought is to have a few pots / planters that can be move around easily. The planters can be relocated to get a bit of sun for part of the day or every few days and then returned to their home base underneath the maple. This takes some commitment and effort but even 2 or 3 pots can provide a bit of interest and something nice to look at.
Best of luck with this project!