grapevine in trouble
I have 2 very old grape vines, probably 100+years old, both grown inside a conservatory. To my knowledge for the past 25 years they have thrived, One is on a bed roughly 20' long and has its roots growing outside and into the ground, the smaller one is in a 5' long bed and I don't know if its roots get outside or not. Up till this year their growth has been more or less the same, although only one, the biggest, grows grapes.
this year the smaller one has simply not grown, its shoots are roughly 6" long compared to the others 6'. I have never pampered either other than watering if there has been a significant drought.
what has gone wrong this year, will the poorly one survive, can I help it back to health? I should add I live in a village where the first question I was asked when I moved in was "you're not going to get rid of the grape vines are you?"