What is Attacking this Purple Flowering Plant

Hi mfirth, well your plant looks like a Hebe & from your photos I cannot see anything eating yours, unless I am mistaken.. What signs of any bugs can you see..?? Hebe are not really attacked by anything much as regards pests.. They do suffer with earwigs which cause some leaf distortion & whitefly you can see.. The latter is relatively uncommon..

They are often marked as drought tolerant, but they are not that tolerant of it in fact.. They suffer badly from lack of water.. The stress shows in the leaves & they will droop & turn pale.. Prolonged stress will cause yellowing of the foliage, and brown, necrotic areas will develop on the leaves, especially on the midrib. Not sure if that sounds anything like your problem, but that is caused by lack of water...

After that there is leaf spot, downy mildew or root rot that attack them.. Your photos are quite dark so the leaves are not that clear so hard to really say.. Hope that helps..

 

Hi Mark, I think it is probably the lack of water Mark too, but the Mares tail could be strangling the roots perhaps.. The trouble with Marestail is the more you disturb the roots the stronger it gets.. If it were me I would also trim of the dead flower heads on your hebe & just tidy it up..
Then attack the Mares tail by crushing the stems as th leaves will not absorb it it has to be the stems & applying a weed killer like SBK or a Glyphosate type one.. You will probably have to do it a few times as well..
Protect your hebe if you can & then hopefully it will pick up with a feed & regular watering..