Starting with the observed fact that the rewood's pump works, Id say that one long enough to reach the ground would sufice. Are you suggesting that God personally intervenes with a miracle each and every moment in the life of a redwood?
Just for information, vacuum pumps can't lift water more than thiry feet. So the word pump is irrelevant here, as it is in every large tree.
FYI: Pumps can push water up hundreds of feet if you place them at the bottom of the well instead of the top.
From above, no pump can suck more than thirty feet. From below, a pump can lift a column ... well ... that its horsepower will lift.