I'm growing about 8 varieties in 12 gallon pots in my greenhouse. They fruited about 6 clusters each the 2nd year and about 10 the 3rd. That's about as much as I'll allow. I water once a day in summer.

My favorite varieties are earliest to latest: Flame, Summer Royal, Princess, and Crimson. Summer Royal best overall. It has large berries and great flavor if not over watered.

Summer Muscat is the best tasting grape I've grown but the berries are small and crack badly for me.

What's preventing you from allowing more clusters? Is it the pot size?

That's what seems right in my judgement for the canopy size. It's all a judgement based on experience.

You can get a bigger canopy and therefore more grapes with a bigger pot or by watering/fertilizing more. But too much water or too much fruit and the fruit eating quality will suffer.

Ten clusters is ~10-15 lbs of fruit. That's quit a lot from a canopy that covers roughly 36 sqft.

I know someone who grows grapes in 5 gal. containers aquaponically. He shoots for a couple of clusters per container and may get more over time as it matures.

This post was edited by Fascist_Nation on Mon, Nov 4, 13 at 10:11

That is quite a lot. I'll have 4 vines, so I'm looking forward to plenty of fruit. Thanks fruitnut!