I have a Marechal Foch vine (planted 4 yrs ago) that is just growing like crazy...I mean so bad that last year I let it grow over the trellis and reached well over 15 ft. This year again, it has set nice fruit and they are enlarging nicely but the vines just keep growing and just won't seem to stop. I even noticed new growth setting flower a second time! I already pruned to tidy up twice since the begining of June.
It is planted on the south facing side of a fence and it is not trained in any particular method, except that I pruned it hard last winter, like most and it has only one growing trunk. I live in northern Ontario, zone 4b and there is much winter kill on anything that was not covered in snow.
Do I keep pruning or just let it go wild? Perpahs I left too many growing buds last spring? I was told that letting grow too much will suck the sap out of the plant and drain it but I keep cutting and it just stimulates more buds to grow.
Any advice greatly appreciated.
You might be over fertilizing it... grape vines like it on the lean side, in order to put more energy into fruit production instead of growth. I'd wait till the regular pruning time... and not fertilize any more. I have heavy clay so when I planted my grapes, I heavily composted them... and am paying for it in huge growth... but I am hoping it lasts for awhile, in the end, better soil.
