Grow tubes must be removed before cold temperatures arrive. If tubes are left in place through the winter, the heat inside the tube will cause the plant to come out of dormancy early and perhaps winter kill. Tubes should be removed at least 3 to 4 weeks before the first frost. This will allow adequate time for the plants to harden off. Vineyard irrigation is not usually necessary in the Eastern United States until vines exit the grow tube.
Tubes tend to recycle water by attracting condensation and reducing evapotranspiration.
This effect is enhanced when mulch is used, since mulch helps retain moisture. Extreme care must be exercised when using grow tubes to replace vines in established, irrigated vineyards. It may be necessary to plug emitters near the new plant to avoid overwatering. Do not water directly into a grow tube because this will result in overwatering. Shoot growth should be monitored on a regular basis in both new and established vineyards.