Posted: 18/09/2016 at 18:59
Does the black stuff on the wisteria rub off with a damp tissue? If so, it's probably a black mould which grows on honeydew which is secreted by ahpids and has fallen from foliage above and is common on anything growing underneath trees. Not really harmful, just unsightly. Deal with the aphids and the problem will go away but not worth bothering with this year as they will die soon when it gets colder.
Is the wisteria in a pot? If so, it won't like that at all and needs to be planted in the ground, no matter how poor the soil.
The acer and bay both look as if they've been short of water at some stage - neither of those are at all tolerant of the soil drying out and will be much happier in the ground if you can find somewhere to plant them (both seem to be in pots?) If they need to stay in pots, put them in larger ones and use a John Innes #1 compost which holds water well and is recommended for potted trees and shrubs. If you do re-pot them, leave it until growth restarts in the spring.
Hope that helps!
Last edited: 18 September 2016 19:03:51