Box blight in Ramsgate: how to spot it and what to plant
Damp, humid weather favours the box blight fungus, and Ramsgate's mild coastal autumns suit it. If your box hedge is browning, the news is not that you should panic, the news is what to plant instead.
Why damp weather makes it worse
Box blight (Calonectria pseudonaviculata and its close relative C. henricotiae) is a fungal infection of box. It shows up as brown leaves that fall, leaving bare patches, black streaks and dieback on young stems, and, in wet conditions, white spore masses on the undersides of infected leaves (RHS).
The fungus is most active in rainy seasons and spreads rapidly in warm, humid conditions. It can survive on fallen leaves for years, so once box blight is in a garden it tends to come back.
Box tree caterpillar is the other problem
The other killer is Cydalima perspectalis, the box tree caterpillar. It is now widespread in south-east England and returns season after season. Repeated heavy defoliation over successive seasons can kill an established box hedge.
Quick check: push your fingers gently into the canopy. If you feel webbing and green and black caterpillars, with curved bites out of the leaves, it is the caterpillar (or both). If leaves are browning and dropping and young stems show black streaks, with no webbing or caterpillars, it is blight. In wet weather blight may show white spore masses under the leaves (pink spore masses point to Volutella blight, a less serious problem).
What to plant instead
Three replacements that actually work on Thanet's alkaline chalk-Thanet-Sand topsoil, in the order I would specify them.
1. Ilex crenata (Japanese holly)
Closest visual match to box. Tight, small, dark-green leaves. Tolerates clipping to within a centimetre of itself. Genuinely happy on chalk. Slow, a young plant in this autumn will be a usable knot hedge in three years. If you want instant edge, budget for larger nursery stock. Ask the nursery which cultivars they recommend for clipped hedging; 'Convexa' is a common one.
2. Yew (Taxus baccata)
If your hedge was over knee-height, yew is the right answer. Native to the North Downs chalk, happy on Thanet's thin alkaline soils, and effectively immortal. Yew hates waterlogging, which means it actually performs better on the free-draining Thanet chalk than on heavier inland loam. Counterintuitive, but it is about drainage, not depth. Minimum sensible yew hedge is around 60cm.
3. Euonymus japonicus
The dark horse. Brighter, slightly larger leaves than box or Ilex crenata. Tolerates the chalk, tolerates a hard clip, and unlike yew it is fine in partial shade, useful in older Ramsgate walled gardens where mature trees have closed the canopy. Cultivars: 'Green Spire' for upright, 'Microphyllus' for a smaller leaf closer to box scale. Salt-tolerant too, unusually for a formal clipped-hedge plant, which makes it worth considering on exposed West Cliff frontages where many other formal hedges struggle.
What you'll be offered that does not work
Privet is the obvious cheap substitute. Fine for a tall boundary hedge. Wrong for a low knot, semi-deciduous on chalk in a cold winter, throws lush growth, looks nothing like box.
Lonicera nitida gets recommended a lot and should not be. It is quick, but structurally floppy. You will spend the rest of the hedge's life staking it back after every rain shower.
Box again, treated. Blight-resistant cultivars ('Faulkner', 'Heritage', 'Renaissance') are more resistant, not immune. In a Ramsgate garden where blight and box tree caterpillar are both in the local environment, you are buying a few years before the same problem returns.
If you decide to replace
- Take everything out, including the roots. Blight survives on fallen leaves and debris for years. Remove fallen leaves, strip off the surface of the topsoil, then bag the material and bin it; do not compost it.
- Replace with a different plant, not more box. Box blight affects box and its close relatives, so Ilex crenata, yew and Euonymus japonicus are not at risk from it.
- If your old hedge is inside the Ramsgate CA, removal itself does not usually need a notice (hedging-species removal is exempt). But standards within the hedge line over 75mm at 1.5m need six weeks' notice. Easy to overlook on an old, lost-in-the-canopy line. I check before quoting.
Want this looked at?
Send a couple of photos and your postcode to hello@ramsgatehedges.co.uk or 07763 100 477.
Sources: Royal Horticultural Society box blight and box tree caterpillar pages (rhs.org.uk/disease/box-blight, rhs.org.uk/biodiversity/box-tree-caterpillar); Thanet District Council conservation area guidance.