You need 2m of ribbon, 0.5cm or narrower and an odd number of lavendar stems (I used 9 and 13) roughly equal length.
Strip off the leaves.
Tie one end of the length of ribbon just under the flowers.
I need more pictures, I'll add them when I get chance.
Fold the stalks over the flowers at the ribbon.
Take the long end of the ribbon and weave in through the stalks. It's a bit fiddly at first but once you've done the first two rounds it get easier. You need to pull it really tight because as it dries out it will get looser.
Leave it over night to dry out and then tighten up the weaving.
Once you've finished the weaving, you can either tie it off and have the stalks loose or wrap the ribbon all the way down and finish with a bow. You might find a little superglue useful for securing the ribbon!
I included two stalks for the blue one