Answer: I suspect you are seeing the related Cornus sericea (sometimes called C. stolonifera) rather than Cornus alba along the medians. In my experience the variegated shrub is less vigorous than the green leafed types, and C. alba seems less heat/humidity tolerant than C. sericea. Since your local nurseries are not recommending it, I would defer to their localized expertise. You might ask them what they would suggest as an alternative. Your local county extension may also be a good resource for localized plant recommendations based on a more detailed understanding of the specific location (eg sun and wind exposure, soil type and moisture levels, etc.) where you want to plant a shrub and your design goals.
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