How to plant street tree beds

Guerilla gardening: How to plant street tree beds

28th Jun 2023 Home & Garden

Rewild your city with guerilla gardening! Here's how to plant street tree beds and turn streets into eco-corridors

As a child, John Welsh loved helping out in his parents’ garden and, after finishing his studies, his first job was in a plant nursery. “But then I got pulled into a corporate career for 30 years,” he sighs.

That began to change in 2016, when John’s mother moved in with him and his husband. “She was shocked by the level of litter and dog foul in the street and suggested we plant some of the leftover plants from her old garden into the shabby tree beds outside.” Sure enough, the plants flourished, and the mess around them subsided. “It was a revelation: I could actually change something, rather than just sitting at home like a pompous old fart, whinging or shouting at the council.”

"People up and down the street stopped to ask what he was up to, and strangers turned to friends"

By the following year, John had created biodiverse gardens in six tree beds along the street, using only plants from saved seeds, cuttings, or division.

People up and down the street stopped to ask what he was up to, and strangers turned to friends. The next year was set to look better than ever. But just as the hotly anticipated rainbow of spring blooms was set to emerge, Camden Council’s subcontractor sprayed the entire street with glyphosate. “Everything died,” John announces matter-of-factly.

But the residents rallied together: donating whatever plants they could to refill the pits and committing to protecting them. Now, there are 15 tree bed gardens along the street and a group of neighbours help look after them.

The transformative experience inspired John to return to professional gardening: “I’m back to where I wanted to be when I was 21, but lacked the confidence to do it.” He started Rewilding the City, an initiative working with communities to turn lawns into meadows and streets into eco-corridors.

What are street tree beds?

Tree beds, also known as tree pits, are the gaps in the pavement (or occasionally large planters) in which street trees are planted. These are also a great place to start! You’ll find them in most neighbourhoods, usually bare at the base.

"Trees love company! Wild trees usually have a host of smaller plants growing beneath their canopy"

This nakedness is an unnatural state of affairs: trees love company! Wild trees usually have a host of smaller plants growing beneath their canopy, and planting under street trees can help recreate this healthy ecosystem. However, planting the wrong companions, or using the wrong method, can damage trees.

Creating and caring for a garden in a tree bed will mean you’re supporting the tree, not only by protecting the soil it lives in but by watering it as you water your garden.

What to plant

Do:

Include native, resilient plants. Look to see which species are thriving in your area, especially in other local tree beds.
Plant a diverse range of species, including ground cover among taller stems.
Choose shade-tolerant plants if the tree casts a big shadow. Spring bulbs found in woodlands, like bluebells (hyacinthoides non-scripta) and wild garlic (Allium ursinum), work well below deciduous trees, taking advantage of the spring sunshine before the tree has leaves.

Avoid:

Plants with a high demand for water, like hollyhocks (Alcea rosea) or sunflowers (Helianthus annuus), unless you plan to water the bed frequently. They can compete with the tree—especially if it’s a young one—potentially killing both the tree and your plants.
Planting climbers, such as clematis (Clematis spp) and honeysuckle (Lonicera spp), which could engulf the tree.

How to plant it

Do:

Maintain a distance of around 10-15cm (4-6in) between the base of your plants and the base of the trunk to prevent the bark from moulding.
Plant densely, to cover the soil and help pollinators find the garden.
Create a low wooden border around the edge, which will both protect your planting from being trampled and stop it spilling out and obstructing the pavement.
Feed and enrich the soil where you’ll be planting (but avoid raising the soil level).

Avoid:

Harming the tree’s roots: use a trowel, not a shovel, and work carefully around them; never pile soil or mulch up over the root flare (the bit where the roots join the trunk), as this can cause decay or hide root problems. Planting if the tree is a very young sapling (less than four years old), as any plants could outcompete it for water and nutrients.

Plant ideas

Bulbs, eg, wild daffodil (Narcissus pseudonarcissus), snake’s head fritillary (Fritillaria meleagris), wild tulip (Tulipa sylvestris).
Herbaceous perennials, eg, meadow cranesbill (Geranium pratense), wood anemone (Anemone nemorosa), common cowslip (Primula veris).
Annual wildflowers, eg, cornflower (Centaurea cyanus), common poppy (Papaver rhoeas), corn marigold (Glebionis segetum).
Winter interest, eg, primrose (Primula vulgaris), lamb’s ear (Stachys byzantina).

Excerpt from Get Guerrilla Gardening by Ellen Miles (Published by DK, June 8, 2023)

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