Congrats on the new plot!! Exciting isnt it? :-D
Yup, like many said, perennials can't be composted, unless you use a hot composter. Its hard to be sure with a regular compost heap whether it will get hot enough to kill the plants. But drying them out should work ok too, especially in this weather.
I've been told that bramble roots will rot down ok if you put them in a barrel of water (though i've got so many that i would need a LOT of barrels, there'd be no room to grow anything lol)
When i started clearing mine, i cut all the nettles first and popped them into a big bin of water to rot down- its an EXCELLENT nitrogen feed!!! Brilliant for your leafy veg, just water at the base of the plants with it. You know its ready to use once it starts to stink something awful.
Glass seems to be ubiquitous on plots... I found whole panes of greenhouse glass spread out about a foot underground in mine.... sigh, why do ppl BURY things!! Of course i didnt know it was there until i put my fork through it, shattering it into a zillion pieces.... also found other bits of greenhouse, shoes, roofing material, HALF a rotted rusting wheelbarrow, and a v large heavy sheet of metal, rusted (no idea what that was)- and I've only dug about quarter of the plot so far- slows you down something serious trying to unearth things- so hopefully glass will be all you find. (mine was seriously overgrown for 20 yrs+)
BUT, most importantly, what i wanted to say is- part and parcel of turning the soil over, what will happen is that years of seeds that have been waiting for the right conditions to germinate, will do exactly that.
I was getting a but twitchy about making sure i got ALL the bindweed roots out, until i realised... there's hundreds of thousands of bind weed seeds here that i cant see, that will germinate sooner or later.....
*tumbleweed moment*
and then i realised, that theres no reason to get twitchy about missing a few bits of root- things will pop up and they'll be easy spotted and pulled before they get going much so.... theres NO point getting frustrated about it...
Theres a few allotment neighbours of mine who put in all the hard work digging and who got really despondent about that- because they felt they'd "done something wrong"- really expecting it to stay clear for a bit longer. It won't. Its natural.... so just hoe em up when the weeds are young- its all compost anyway :-)
Good luck/ break a root!