Sambucus black elder aphid infestation
I've just noticed that my huge 3yr old sambucus is covered in black aphids. Properly covered - every branch joint is swamped with them. I did see 4 ladybirds - hurrah - but there's no way they'll get through this infestation alone.
What's the best thing to do - there's way too many aphids to squish, but at the moment it doesn't appear to be affecting the new growth. Will that change as the swarm gets tucking in, or am I fine to leave it to nature? Is there anything non-toxic that I can use to help the ladybirds get the numbers down? I've just never seen such an infestation!