Sometimes the neglected patch of dirt surrounding a street tree is all the dirt you have. Her photos inspired us to ask Maureen O’Brien, the Brooklyn Botanic Garden’s community field manager who judges the tree bed category for the annual Brooklyn’s Greenest Block Contest, for tree bed planting tips.
Photography by Betsy Pinover Schiff, courtesy of Monacelli Press.
What is a tree bed?
A tree bed is the opening in the sidewalk where a tree is planted.
Why plant a tree bed?
If done correctly, a tree bed with added plants can benefit the tree as well as beautify the streetscape.
Before you plant:
Not all tree beds are good candidates for gardening, especially if the resident tree is a very large old one. The mulch will give the bed a cared-for appearance and add nutrients to the soil as it breaks down over time.
On the subject of soil, O’Brien is adamant. And because most tree roots are in the top 18 inches of soil, adding dirt can interfere with the crucial uptake of oxygen.
Preparing the soil:
Choosing the Right Plants:
The ideal plants for tree beds are petite annuals or perennials that have small root systems. Native plants have the added advantage of attracting pollinators such as birds and butterflies, but beware of those such as Queen Anne’s Lace which have long taproots.
Low-growing ground covers make a good living mulch. Marigolds (Tagetes species), nasturtium (Tropaeolum species), rock rose (Portulaca species), and zinnias (Zinnia angustifolia) will bring life to the sunny bed of a young tree.
Plant Palette Ideas:
Because they bloom before most trees leaf out, spring bulbs are a good choice and provide early color. In shade, interplant them with ferns or hostas which will appear as the bulbs are fading and cover their dying foliage.
Seasonal Color:
You may want to add a tree guard to give your bed a finished look and send a message to passersby that the bed should be respected.
Tree Guards:
It is important that tree guards not present a tripping hazard for people on the sidewalk and that the curb side of the guard is left open to prevent damage to car doors.
Tree Bed Maintenance:
The better groomed your tree bed appears, the more likely people will respect it. This can present a challenge since it is really impossible to set up irrigation in a tree bed.
Good luck adding a bit of greenery to your city sidewalk.