Too much water, not enough water, and fungus can cause them to fall off.
> Some grapes will do well in acid soil, others wont. I am not sure about
> Concord, but Mars is a take off of Concord and they do well. I know
> Thompson didnt make it in Arkansas, and we had acidic soil there. > > Dwayne
>
>
>>I planted 3 grape vines 3 years ago and this is the first year I am
>>getting grapes. I'm so excited! Now the grapes are about half the size
>>of a marble and half of them have fallen off the bunches already. Is
>>this a sign of my vines lacking something or getting too much of > > something?
>
>>The Concord vines are covered with bird netting just to keep those
>>suckers in check and the pH of the soil is around 6.0 - just checked > > today.
>
>>Any advice would be great.
>>Thanks,
>>Quin
>>
>
>
>