Plant of the week- Buddleja davidii ‘Black Knight’ 


Well after a few weeks break with the Rose of the week, we are back to the plant of the week but with a slight difference. For the next month it’s The Butterfly count. This is carried out each year by the Butterfly conservation to monitor the more common types of butterflies we see in our gardens. So to celebrate this, for the next month I will be focusing on plants that are looking great at this time of year but also attract in butterflies. To start this off, it has to be the Butterfly Bush, Buddleja. There are so many great forms of great plant (check back in a few weeks for a more indepth look) but I have chosen my favourite form and also one of the darkest forms of Buddleja, Black Knight. 


Buddleja davidii is a native of Central and west China, were it grows up to 8000ft above seas level, where it can grow in some  pretty poor soils, hence the reason it selfseeds and grows in any space in the uk, whether it’s a bit of waste ground, roof top or sides of a quarry. Sadly this ability has labelled it as a invasive plant. It was introduced into Europe by the French missionary Father David (hence davidii) from east Tibet in 1869. Buddleja itself was named of the British amateur Reverend Adam Buddleja by Von Linne in 1737. The form ‘Black Knight’ was bred by the famous Moerheim nursery in Holland by Ruys. It has become the most popular form of Buddleja to be grown mainly due to is stunning flowers that are the darkest form of any Buddleja. The flowers funny enough are smaller than the normal size of Buddleja flowers by are bourne on plants that will quite happily make 4m in height. It was grow away in most forms of soil, although it will struggle on heavy waterlogged ones. 


It is pretty pest and disease free apart from the horrible eel worm. They are a microscopic nematodes that live in the young shoots of leaves of the plant, they tend to cause yellow patches in the leaves and deformed growth on the tips of new growth. To check if it has it, cut an infected shoot up and place into a glass of water and leaves for 30 minutes, if they are present, you will see tiny little balls of these tiny tiny worms at the bottom of the glass. To treat, best way is to remove infected shoots during the growing season and all old leaves in the winter and burn. 

Pretty easy to prune, I tend to prune mine in March and more details can be found here https://thomasdstone.blog/2017/03/17/job-of-the-week-pruning-buddeja/

2 Comments Add yours

  1. John Kingdon says:

    Phew! Another plant I already have, albeit a different form. My bank balance lives for another day. As does my buddleia (I’m in the “I” spelling camp) having earned a reprieve by starting to slowly attract butterflies back into the garden. And then quickly attracting them. And apart from allocating space, hardly any work to maintain.

    1. thomashort says:

      See I do listen John 😀 going to be on my best behaviour from now onwards………… pretty easy aren’t they, so pleased you getting a few on there now, any signs of the red admirals yet?

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