Dear Master Gardener
I have a well-established mature 40-year-old Hicks you Hedge. Every year we have to clean out the weeds that grow at the base and into the lawn. Is there preferably an evergreen ground cover that you would recommend growing under it. We have tried pachysandra but it it just seems to want to grow out into the lawn and provide a nice base for all sorts of little weeds to grow under the Hedge. If not an evergreen ground cover perhaps a succulent that would spread under the Hedge.
To make things a little more difficult there are two mature black walnut trees that grow in the Hedge which of course means many plants won’t grow there. Appreciate your help.
Thank you for contacting the Toronto Master Gardeners with your question about a ground cover to plant under your Hicks yew (Taxus x media ‘Hicksii’) hedge. A few things to consider:
As with any plant that is planted under trees, your new ground cover will be competing with your hedge for water, nutrients and light.
The growing conditions for your hedge must be ideal for it to have thrived for so many years! Typically, these conditions include full sun to part shade (although Hicks yew can tolerate more shade than this), and most importantly well-drained soil, preferably moist (not wet) sandy loam (although Hick’s yew is drought tolerant, especially at maturity). Your new ground cover would need to be happy in these conditions, although it would probably get less sun than your hedge, perhaps mostly shade.
The height of your ground cover will need to be such that good air circulation is maintained below your hedge.
Given the age of your hedge, its root system is likely extensive, so the soil below it might be difficult to plant, and you will also need to consider the space that will be needed by the root system of your new ground cover. Shallow rooted is probably best.
Some suggestions about what not to grow: pachysandra (which you have tried planting) is one of these. While this plant has not been identified as invasive by the Ontario Invasive Plant Council, it is on their Watch List because it can be invasive in natural areas. There is a helpful booklet authored by this Council called Grow Me Instead which has a list of invasive plants in Ontario and suggests non-invasive alternatives.
There are lists of potential ground covers for you to consider at the links below. Please keep the above list of invasive plants in Ontario in mind as you look at the plants suggested in these links. Some of them originate outside Ontario.
Broadleaf Evergreen Ground covers: A Toronto Master Gardeners Guide. Click here
Native perennials for shade: your living landscape. (Toronto Master Gardeners) Click here
Ground Cover Plants for Missouri Gardens. (Missouri Botanical Garden) Click here
Shade Ground Covers. (Savvy Gardening) Click here
This article has lists of plants to consider given the presence of your black walnut trees. (Johnson County K-State Research and Extension) Click here
Finally, you may wish to consider putting some type of mulch instead of plants under your hedge. There are some options to consider here.
Good luck with your ground cover!