How to fix my overgrown grapevines?

Question

Hello, I moved into my house three years ago and there were grapevines that have been over grown for a few years. The first year we were here they had black rot. Last year, I cut them back as directed online and they didn’t produce, but they also said that they wouldn’t produce that first year. This year, I trimmed them back in the spring and had to cut a lot off because it had grown so much but I was still hesitant on cutting too much because I didn’t want to shock or kill it. They are producing, however, they also have black specks/spots on a lot of the grapes. They don’t seem to be rotting, at least not yet but they have been like this for a few weeks now. I don’t know if I just didn’t cut them back enough to help fight against black rot or if they are just in need of nutrients. They are at least double the size of the first time now but still have black dots that don’t seem to be getting any bigger or look rotten. Any advice for these would be awesome since I am a newby to grapes. We don’t know what kind they are. We know they are domestic, seeded grapes.

Answer 1

Grapes fruit best with heavy pruning. A light pruning will not yield sufficient results. This article will help: https://www.gardeningknowhow.com/edible/fruits/grapes/prune-grape-vine.htm

As far as the spots go- It is hard to say without seeing it, but if the dark spots are not changing in shape or size, then it won't be much to worry about. It may just need fertilization. This article will help you to care for grapes: https://www.gardeningknowhow.com/edible/fruits/grapes/growing-grapevines.htm

This collection of articles will offer all of the information that you could need about grapes of all types: https://www.gardeningknowhow.com/category/edible/fruits/grapes