I have done something similar. Cut down some old flower wooden stems from the allotment next door, which the lady has given up, and said help yourself. She was leaving them as said the birds loved them. I cut of the flower heads on the unused allotment as didn't want them to spread to mine, have enough weeds/wild flowers of my own. Stuck them in the peas which I have netted, and hopefully they will grow up them. Don't know what the plant was but it looks similar to your photo. Did search the neglected sites for twigs but as most of the allotment sites are now in use, not much luck. Have some chicken wire but a devil to cut to size.