Box
Weeds That Feed - A Pantry For Wildlife
Each week, through Weeds That Feed, I take a closer look at a single plant and ask two questions.
First: what insects does this plant support?
And second: Would it be beneficial to plant over an ornamental alien species?
This week’s plant is box Buxus sempervirens, a familiar, quietly dependable evergreen that has shaped British gardens for centuries.
Box is often used for structure: low hedging, formality, and definition. Ecologically, it is relatively quiet.
According to the Ecological Plant Profile (EPP) that I produced, box supports:
24 recorded insect interactions in total
That includes:
18 larval and phytophagous (plant-eating) species
6 pollinating species
Among these is one larger moth species, the Satin Beauty (Deileptenia ribeata), whose caterpillars can feed on box. Beyond this, box supports a small group of highly specialised insects, including mites, midges, a sap-sucking psyllid and a lace bug, for which box is the only recorded food plant.
Box is not a generalist wildlife plant. It supports few species, but for some of those species it is irreplaceable.
Box is native to Britain, but only to a handful of sites, largely on calcareous soils in southern England, where it forms dark, dense evergreen thickets on steep slopes.
In gardens and designed landscapes, however, box has been planted far beyond its natural range. What we think of as a quintessential garden plant is, in ecological terms, a species with a very limited native footprint.
It also carries a strong cultural history. The name buxus comes from Latin and Greek roots meaning “box”, referring to the dense, fine-grained wood once used for small containers, religious objects, chess pieces and printing blocks. Sempervirens simply means “always green”.
Historically, box has been associated with remembrance and mourning, with sprigs carried at funerals and thrown into graves, a reminder that its role in our landscapes has for a long time been symbolic as much as practical.
If this were only a question of ecology, the story might end there - a native plant, modest in its wildlife value, supporting a narrow specialist fauna.
But the situation has changed.
The arrival of the box tree caterpillar in 2008, a non-native moth from East Asia, has fundamentally altered the picture. Its caterpillars feed almost exclusively on box in the UK, repeatedly defoliating plants and often killing them outright.
Alongside this, box blight, caused by fungal pathogens, has made box increasingly fragile and management-intensive in gardens and landscapes.
The result is uncomfortable but unavoidable. Continuing to plant box now increases habitat for a non-native pest and risks placing further pressure on valuable, already vulnerable and ‘rare’, as categorised by the Botanical Society of Britain & Ireland (BSBI), wild box populations.
This is one of those rare moments where stepping back from planting a native species may actually be the more responsible choice. Which leads us to the question. Which plants might we plant?
Weeds That Feed - Grow This Instead
The aim of Grow This Instead is not to abandon the structure or design of more traditional gardens, but to rethink plant choices based on ecological contribution.
Some commonly used substitutes perform poorly.
Euonymus fortunei, from East Asia, supports 3 phytophagous insects and 1 pollinator - extremely low.
Ilex crenata (Japanese holly) supports no phytophagous insects and just 1 pollinator.
They provide shape, but very little food.
More promising alternatives exist:
Native yew — Taxus baccata
Yew retains structure, longevity and shade tolerance, while supporting 18 insect species, including:
14 phytophagous insects
7 moth species (including the satin beauty that the box also feeds)
and 4 pollinators.
Importantly, it does not amplify the spread of box tree caterpillars. There are even dwarf cultivars, such as Taxus baccata ‘Repandens’, suitable for lower hedging.
Gorse — Ulex europaeus
Gorse is an unsung hero, which I am striving to change! It supports 118 insect species including:
71 phytophagous (herbivorous) insects - including 8 butterfly caterpillars (one vulnerable species and is primary food plant to three caterpillars) and 16 larger moth caterpillars
47 pollinating insects
It won’t suit every setting, and its yellow flowers still divide opinion, but ecologically it is a powerhouse. Nature, it’s worth remembering, rather likes yellow.
I never want to casually recommend against a native plant. But the evidence seems to suggest that in this case it might well be the prudent thing to do.
Box had, and still has, a place in our landscapes.
But right now, planting it widely risks doing more harm than good.
This is a moment for restraint, for thoughtfulness, and for choosing alternatives that support nature without amplifying known problems.
Sometimes, choosing plants that wildlife choose also means choosing not to plant what tradition tells us to.
Andy.
