I’ve been researching shrubs for deep shade that are also drought tolerant for a spot we have under an overhanging Manitoba maple tree. Would you be able to offer any comments on suitability based on your experiences with the following shrubs, and/or recommendations on which may be best suited? Or, are there any others that you feel are superior to these?
Aronia melanocarpa (Black Chokeberry)
Cornus racemosa (Gray Dogwood)
Eleutherococcus sieboldianus (Five-fingered Aralia) [aka Acanthopanax sieboldianus]
Staphylea trifolia (Bladdernut)
Viburnum acerifolium (Maple-leaved viburnum)
Thanks very much
Ah, the deep shade under a Manitoba maple is the most challenging garden spot, not just because of the shade but because the maple will consume all the moisture and nutrients, and the roots will take up most of the soil space. Because you are talking about shrubs, I assume you are planning to plant these at quite a distance from the maple trunk. However, there will still be the challenges I’ve listed.
That said, your best bet among the shrubs you have listed may be the Aronia melanocarpa. All of the plants you list really prefer part shade, not deep shade, but especially the cornus and viburnums. I grow the Eleutherococcus sieboldianus in dry part shade. It tends to grow very tall and rangy and needs regular pruning(avoiding the thorns!) to keep under control … I suspect that tendency would be exacerbated in deep shade, so I would not grow it in your situation. The bladdernut gets very tall and suckers, so may have a somewhat messy appearance in your garden. The chokecherry will be somewhat looser and rangier in the deeper shade and won’t fruit well, but overall, it will maintain a shorter, somewhat tidier form than the others. It also has great fall colour.
Good luck dealing with the dreaded Manitoba maple challenge!