A north border built in six layers, for twelve months of interest
A long north-facing border that had been a single line of conifers, gloomy for eleven months and worse in the twelfth. The brief was simple to say and hard to draw: something to hold the eye in every month of the year.
The answer is the section drawn on our home page. It is six layers stacked in one bed — multi-stem canopy for height and winter structure, an understorey read at eye level, a shrub layer massed for cover, the herbaceous layer for the flowering months, and a floor of groundcover over twelve thousand bulbs. Each layer has a place in the section: a mature height above the datum and a root depth below it, and they are chosen so their roots do not all compete in the same 300mm of soil.
It was built from the bottom up in exactly that order — reduced level, land drain, four hundred millimetres of topsoil, then the planting biggest-first while the bed was still open to a barrow. The canopy went in first, in November, bare-root.
The section, as drawn
Section drawing · built in layers
The layered border
A north-facing border built in six layers, so something holds the eye in every month of the year.
| Layer | Height | Root depth | Planting |
|---|---|---|---|
| Subgrade and land drain | — | 1.15 m | Reduced level dug to formation, a 80mm perforated land drain laid to a 1:80 fall. |
| Topsoil | — | 0.4 m | 400mm of screened topsoil, ameliorated with composted bark, left to settle. |
| Canopy | 2.4–7 m | 1.1 m | Multi-stem Amelanchier and river birch — the height and the winter structure. |
| Understorey | 0.7–3.3 m | 0.7 m | Cornus, hazel and Viburnum — the layer that reads at eye level. |
| Shrub layer | 0.2–1.5 m | 0.5 m | Hydrangea, Sarcococca and hardy geranium massed for cover. |
| Herbaceous | 0–1 m | 0.35 m | Salvia, Geranium and Molinia — the flowering months, cut back each spring. |
| Groundcover and bulbs | 0–0.2 m | 0.18 m | Epimedium and Geranium over 12,000 bulbs — the floor that suppresses weeds. |