From: Joanne O'Sullivan <joanne.osullivan@dublincity.ie>
Date: Wed, Jan 22, 2025 at 3:39 PM
Subject: Boxes around the base of trees are not supported or encouraged by Dublin City Council
To:

Dear Environmental Groups,

 

We would once again like to draw your attention to the fact that building boxes around the base of trees is detrimental to their health.

We discourage this and would ask that if you would like to enhance the base of trees in your area with plants that you do this without building structures around them.

 

The following list of plants were recommended to me by a gardener in DCC – they self-seed easily into cracks in paths and walls and thrive with very little soil or maintenance. These are all plants that do well in tree pits.

The key with planting into tree pits is to use very small plants as it will be very hard to dig into the soil due to the tree roots. Smaller plants will have a much stronger chance of taking root once they are kept watered in the weeks after planting.

 

1.      Antirrhinum – I would try these as direct sown rather than as plants. Simply harvest the dried seed heads from established plants and scatter over the tree pit once the pit has been weeded and the soil scuffed up.

2.      Verbena bonariensis – I have seen these absolutely thriving in tree pits where they have self seeded from neighbouring gardens. I would try as direct sown or as very immature plants for the best chance at success.

3.      Campanula carpatica or campanula poscharskyana are great rockery plants that often thrive in cracks in walls so the dry environment of a tree pit is perfect for them.

4.      Stachys byzantine – lamb’s ear. Divides very easily and not difficult to establish from small divisions. Great groundcover for dry sunny tree pits. Will not like shady spots.

5.      Hardy geraniums – establish as small divisions from mature plants. Great groundcover.

6.      Erigeron karvinskianus – Mexican flea bane – small daisy like flowers that self seeds very well. If you get a couple established on a road they will spread so easily and look incredible, growing out of cracks in walls and pavements and in the neighbouring gardens.

7.      Erigeron glaucus – bright pink flowers that will be a carpet of blooms all summer.

8.      Poppy – the field poppy, Papaver rhoeas do very well in dry poor soil so will establish well in tree pits once the soil is scuffled a bit. Harvest seed from ripe seedheads and scatter liberaly on the soil.

9.      Cetranthus rubra – red valerian – seen in abundance in coastal areas and establishes very easily from seed.

10.   Linaria purpurea – Purple toadflax – a beautiful purple wildflower that will spread very easily and requires very little maintenance.

11.   Diascia and nemesia are two bedding plants that I have seen thrive in tree pits also and will often survive for a few years providing we do not have a very hard winter. They are both very easy to propagate from cuttings.

 

All of these plants are pollinator friendly.

 

I have attached an image showing tree bases with boxes that are damaging to trees and some images showing tree bases planted without box structures around them that are ok.  

Important note: We cannot guarantee that any planting you do will be protected during footpath maintenance.

With best wishes

Joanne

 

 

Joanne Ní Cheallaigh (O’Suileabhain) I Oifigeach Idirchaidrimh Comhshaoil

Oifig Cheantar an Lárthuaiscirt, Comhairle Cathrach Bhaile Átha Cliath,

Ionad Cathartha an Taoibh Thuaidh, Bóthar Bhun Raite,

An Chúlóg, BÁC 17.

Phone: (01) 2228541 I 087 2868325 I *I northcentral@dublincity.ie