Hi Sallym and a big welcome.
I am new to wine making and am thinking of having a go at the parsnip.
I have tried elderflower- it's not gone right at all
marrow - also not right
home grown grape---fantastic
rhubarb- should be fine
The elderflower I will have to keep trying with as it has very sentimental attachments for me...lovely Aunt made it in days gone by...first time tiddly for me