Box ball dieback

Dieback on newly planted Buxus

A couple of the box balls at a property where I often work are not looking good. The Buxus was planted in April- not by me I should add.

Symptoms

Box blight is my first concern, especially with browning of leaves like this. But no tell-tale black streaks are on the stems- an indication of Cylindrocladium buxicola (box blight).

Box ball dieback

Unusually this Buxus has a patch of healthy new growth on one side. Gives me a clue to look at the roots and I soon see a reason for the dieback.

Diagnosis

The box ball has been planted on an angle with one side of the rootball raised out of the planting hole. Buxus roots are very fine and can dry out easily. This is why I always advise mulching around the base regularly.

Badly planted box ball

The exposed roots on this Buxus have dried out, resulting in one side of the plant not absorbing enough nutrients and moisture to sustain leaf growth and causing dieback. The area of the rootball in contact with the soil has put on new roots, which in turn has delivered enough moisture and nutrients to encourage the small patch of new, healthy leaf growth.

Solution

Replanting maybe a possible solution for this box ball. But that is no easy task. So in this instance I am going to mulch around the base of the ball and hope the Buxus will recover.

Regular watering can help during Summer. Little and often is best to avoid the roots sitting in damp soil. Using leaky hose is ideal. This needs to be wrapped around the top of the whole rootball- not like in the photo above.

I did spray the Buxus with a fungicide, more as a precaution than anything else. Sick and stressed Buxus are more prone to fungus infections, in particular Volutella blight (Pseudonectria buxi).

Fungicide Buxus

I haven’t cut away any of the brown areas as hopefully there is still life in the stems. The leaves will most likely fall off and I will be careful to clear these up- again to avoid risk of fungus infections. If the Buxus does manage to put on new root growth then with luck I will start to see some new leaf growth in the Spring. Check back next year for an update .

9 Replies to “Dieback on newly planted Buxus”

  1. Thanks so much for all of this information James. Now I understand what best to do and check in Cases like this. Every little bit of correct action helps it seems. Looking forward to seeing the outcome in the months ahead. Thanks a million for this information. Cheers, Tre

  2. Thank you James for your advice, clear instructions and pictures. I’m sure many people will appreciate it.

  3. Out of a row of 38 buxus balls, three look decidedly ropey. I water properly and wondered if they had blight so I sprayed the fungicide you use but they just look very dry and crispy with brown leaves inside the ball . Should I put some buxus granular feed around them after usu v the spray? Or dpi just give up the ghost and dig them up?

  4. Hi James … you really answered a question that’s been puzzling me I’ve had 3 go in exactly this fashion – not blight and only one side. All in the new raised planters.. I’ll give them a good mulch and see if that works. Brilliant advice as usual 😊

    1. Thanks Sue. Sounds like the box are starting to put on some new root growth so worth persevering with them. Could be the side that is in the sunshine the most that struggles. The Buxus will cope better when they establish.

  5. Great observation on these James. Very helpful. I planted a new buxus africana hedge in spring. About 30 1gal plants. A couple of them have started looking a little yellow. Could those need some food? I did sprinkle in bone meal in each planting hole, and gave them all a foilar feed in late spring. Haven’t fed since.

  6. James I am so glad to see this post I have this very problem and didn’t know what to do. I assumed it was the heat here
    in Texas and too much sun. Thanks and love your post
    Tricia

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