Transplanting a grapevine? It's a single vine about 8 years old. It's growing on the southern side of my house

a little too close to the porch. I'd like to screen in the porch this summer but I know the vines will destroy my work, besides it will be hard for me to get at the grapes. I'd like to move it, not very far, just away from the porch. When is the best time to do so and will I damage the vine if I try? How much of the root will I have to get? Thanks so much, I hope someone out there has some knowledge that will help me.

Transplanting a grapevine? It's a single vine about 8 years old. It's growing on the southern side of my house
You should firstly thoroughly wet the soil around the vine, then dig a fair size amount of soil up with the root ball. Make sure you cut the vine right back to allow it to survive the shock of transplanting. I'de also take a few good cuttings, and leave them in pots, till you're sure the transplant was a success.
Reply:It is always iffy transplanting established plants. Grapes have an extensive root system and will almost certainly go into shock after a transplant. The best time of year to transplant things depends on where you live. If your area is prone to long hot summers the best time to move it is in the dead of winter, from Dec-Feb. You can give it a shot now, but don't be too alarmed if it it dies. Grapes are easy to come by, it it dies buy another one.

Dig as big a rootball as you can handle, 2-3 ft in diameter and about 1 -1.5 feet deep is usually about the limit for one man. Actually digging up a rootball is a long discussion in its own right. You can help the move by doing it over the long term. Partially dig it out (about a 1/3 of the circumference)and amend the soil in that area, so that between cuts on the root system the previous cuts have a chance to recover and regrow. If you follow that methodology, you should have one that is ready to move by Sept/Oct.