Posted: 21/01/2017 at 18:52
Why are you putting them in the garage, joanna?
Alliums are hardy. Plant them in a pot if the ground isn't suitable, or you don't have a place for them yet. They'll dry out if you just leave them. Or rot. They may not flower very well this year, but they'll be fine for next year.
Depending what the other bulbs are, you can do the same with them. If they're not hardy types, you'd still be better getting them into a pot and protecting them with bubblewrap, fleece or plastic until it's warm enough to plant them out. If you have some bricks or timber, or something similar, you could make a basic cold frame for them. They'll need some light now, so a garage isn't really suitable.
The forsythia and buddleia, like the peony, are also hardy. Pot them up too. Just keep them somewhere sheltered outside for now and once they've put on some growth in a couple of months or so, you can plant them out . Bare root plants won't appreciate being dried out, so avoid that. Potting them up will allow you to keep them moist enough till they start growing.
Hibiscus is a bit more tender I think, so will need some protection. I would get that in some soil/compost anyway. I've never grown it as I doubt it would be happy up here in the Scottish climate.