Buddleja davidii
 

Hi, I have a Buddleja davidii. Its leaves are going yellow and are falling off, I'm not sure why. We haven't used any chemicals near or on the plant. It is planted next to an apple tree that has grey, powdery leaves, but I can't see the same powder on the leaves of the Buddleja. Any advice would be greatly appreciated.

Hi there. The apple tree sounds as if it has mildew. Is it in a rain-shadow (close to a fence or wall?). This can sometimes create a propensity for an infection like this.

What are the soil conditions and what aspect is the buddleia growing on?

Hi, thanks for the speedy reply. The apple tree is close to a wall, and after looking up about mildew, I think you are probably right. Thanks

It's clay soil (I'm sorry, I'm not sure what you mean by aspect - if you are referring to the amount of sunlight, the buddleia has direct sunlight from around 9 am 'till dusk in the summer months)

Thanks for taking the time to reply

(A slightly less than green-fingered) Stanley

A pleasure, Stanley. Now, the yellow-leaved thing can have many causes that are related to nutrient deficiencies. Sometimes the nutrients are there, but there's another problem that prevents uptake.

Is the rest of your garden growing strongly?

I had this on a number of plants when we bought this house two years ago - the garden had been neglected for many years. Rather than try to pinpoint which nutrient is missing, do you have a good compost available? Try to mulch round the plant and see what affect that has.

Hi,
The rest of our garden is growing well (except for the muddy patch, where the birds have discovered birdseed). I will get some good compost and see where it goes from there. Thankyou.