Plant selection under a large cherry tree

(Question)

Dear Master Gardener
I live in the St. Clair / Dufferin area of Toronto and have a 20-year old cherry tree in my back yard. I want to beautify and control the weeds under the tree. At present, I have a thin layer of natural cedar mulch under the tree; however, the weeds are taking over this area. Two questions: What are the best plants for under cherry trees? How do I proceed with planting under the tree without disturbing the root system? Many thanks

(Answer)

There seems to be little specific data available on planting under cherry trees but horticulturist Doris Taylor writing in Fine Gardening magazine cautions that one should be careful when disturbing the roots of cherries and plums. She recommends starting with small plants to reduce soil disturbance, avoiding damaging the trunk and any thick roots, watering well and adding mulch. Plant recommendations for such a dry shade area include shrubs like Carolina allspice, ninebarks and winterberries and perennials like columbine, lungwort and Japanese forest grass.

The University of Minnesota Sustainable Urban Landscape Information Series says that when planting under trees in general, in order to keep root disturbance at a minimum, it is wiser to under-plant trees with perennial plants, rather than annuals, which require replanting every year. This way the disturbance happens only once and thereafter, the tree’s roots and the roots of the perennials co-mingle and come to equilibrium.

Since each under-planting situation is unique, some trial and error may be necessary in choosing plants. You might consider such cultivated perennials as maidenhair fern (Adiantum pedatum), primroses, bleeding hearts or hostas; low-spreading groundcovers like periwinkle (Vinca minor), bugleweed (Ajuga reptans) or Japanese spurge (Pachysandra terminalis) or spring bulbs.