If using more than one type in a bouquet, he notes it's important to make sure the aromas of different flowers don't clash.

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This season, Ms. Bruno likes elegant, hand-painted patterns instead of crisply defined flowers, which don't feel as fresh to her.

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Do not use flowers on the table that don't come from your own garden.

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"I don't know what color those flowers are, " he says while stopped in front of a giant hollyhock that has taken two years to grow.

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Behavioral economics has one more lesson for gift givers: If your goal is to maximize a social connection, don't give a perishable gift like flowers or chocolates.

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For now though, their focus is on more mundane, but nevertheless vital matters such as the wedding dress, the flowers, and how to deal with the great and the good who don't get invited to the wedding.

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