By Mowerman
East Sussex coast,
United Kingdom 
Coronilla died.
I had a Coronilla in a pot which flowered profusely throughout last summer but in the autumn suddenly died. This morning I removed the plant and found no rootball at the bottom of the stem – it only remained in place as it was fixed to a bamboo support cane.
I suspect ants but would welcome any suggestions as to the cause and how to avoid the problem when a replacement is planted.
Thanks
Roy
20 Mar, 2019
Answers
Have you looked into the different types?
May be that yours was an annual?
20 Mar, 2019
it could well have been vine weevil grubs, they are very happy in pots eating roots and they really do not leave any roots behind.
you can buy a product called provado to drench pots to kill vine weevil grubs. also a gritty soil or top dressed with grit discorages females from laying eggs. peat composts are favoured as they are soft and easy to lay eggs in.
20 Mar, 2019