Box Blight

Box Blight Disease(s)

Box blight is a fast-spreading fungal disease that kills topiary and hedges containing varieties of Buxus (known as ‘Box’) within a season.

What is Box Blight? 

Box blight’ is actually one, or a combination, of these two separate fungal diseases:

Usually starts as dark fungal spore
infection – leaves black spots or dark
bare twigs

Box Blight Cylindrocladium

Image rights: Wikimedia Commons License


Leaves turn brown and wither but stay
fixed to the plant

Box Blight Volutella

Image rights: Wikimedia Commons License

 Fungal pathogens, or disease spores, can take only a matter of hours to infect leaves. They are transferred from infected plants via water splashes but can live on leaf litter and dead plants for many weeks or months (see Box Blight Prevention).

Box Blight Treatment

There are a number of fungicides that have been trialled by growers in mainland Europe, with some success, in protecting against initial infection and some that attack the infection - but not all are approved for use on Amenity vegetation (Buxus).

Facts about Box Blight

  • Once a leaf or branch has died it cannot be brought back to life.
  • Signum is approved through an EAMU (Extension of Authorisation for Minor Uses).
  • Warm, wet spring is the worst time for the disease to spread.
  • Dry periods are better to limit disease.

Find out more about Box Blight Disease by Visiting our Blog

How to Prevent Box Blight 

Prevention can be better than cure, but unfortunately its no guarantee. Follow the below advice for the best chance at box blight control. 

  • Collect fallen leaves from all plant species in the vicinity regularly and remove dead plants – then burn... DO NOT compost.
  • Water during dry weather using drip tubes rather than spraying the foliage. Alternatively, you could soak the soil once a week rather than sprinkling multiple times a week.
  • Disinfect cutting equipment after every cut; secateurs, shears and hedgetrimmers– use Propellar or Jet 5 disinfectant.
  • A strong plant will resist the disease better in the first place. Fertilise using small amounts of fish, blood & bone or ideally a slow release fertiliser to avoid provoking a sudden flush of leggy growth that is weaker and more susceptible to spore infection.
  • Some varieties of Buxus seem to withstand infection better than others. Unfortunately, the most popular variety, Buxus sempervirens 'Suffruticosa', seems to be the most susceptible to disease.
  • Newly purchased plants (Buxus or otherwise) should never be planted straight away near box to reduce the importation of infection. Keep new plants in ‘quarantine’ for a short period to observe any signs of disease developing.

Products for Box Blight Treatment

Grid  List 
Grid  List 

Progreen Weed Control Solutions is rated 4.81 stars by based on 682 merchant reviews