Iron sulphate is also a worm killer. It is used to eradicate worms in lawns to prevent mole damage.
Why are they under cover? They are winter hardy plants which shouldn`t be molly coddled. Take the covers off and let them grow naturally.
What colour were the flowers? If white, I would agree on it being officinale.
Daintiness is correct, it is a crinum.
Chris, are you talking about a shrub or rambling climber?
We`ve all done it at some time, don`t beat yourself.lol lol lol Just don`t do it next year.
Another thing to consider is, what is the patio made from?
They sound like Berberis varieties to me. Please do post pics.
You are welcome.