Sugar transport through the phloem vascular tissue relies on water availability to propel photosynthetically derived carbohydrates from source to sink, thus drought is hypothesized to have a major impact on phloem function. Meanwhile, grapevine rootstocks of winegrapes have shown a differential response to drought by varying stomatal closure in response to this stress. We hypothesized that rootstocks that do better at conserving water during drought would maintain higher rates of phloem transport velocity in comparison to rootstocks with poorer water conservation. We tested this hypothesis by dividing growth chamber grown potted plants of Vitis arizonica, V. riparia and V. champinii into well-watered and drought treatments. Plants were then transferred to a fume hood and subjected to carbon-14 radiolabeling treatments where phloem transport velocity and phloem leaf export could be assessed. Leaf gas exchange and water potential were measured prior to radiolabeling. Drought treatment significantly lowered phloem transport velocity, photosynthetic assimilation, transpiration, and stomatal conductance, but these response variables did not differ between species. However, there were significant species and treatment differences for stem water potential (Ψs) and phloem export with V. arizonica having the highest rates of leaf phloem export corresponding to greater stem hydration in comparison to other species in the well-watered treatment; however, in the droughted treatments, V. arizonica saw the largest decline in phloem export while their stems remained more hydrated than the other species. We discuss the tradeoffs between maintaining hydraulic status and carbon export in these species which vary considerably in their habitat of origin.