Best Loire chateaux tour from Paris?

Hi Martha, the best gardens are at Villandry. Each chateau is unique and many have fine gardens - Chenonceau, Versailles - but Villandry is spectacular. Hope you have a great trip!

I agree that Villandry is the top destination. To the east, Chenonceau and Chaumont, which are close to one another, are also wonderful. Chaumont has a very interesting garden festival, as well as beautiful grounds, and large-scale sculpture/art exhibits, all of which I imagine would be of interest to your husband. Chenonceau has beautiful formal gardens, and the interior was decorated with really spectacular flower arrangements in every room--the flowers are grown on site and replaced twice a week.

Villandry, Villandry, Villandry. Most chateaux have lovely gardens but my favorites were Villandry and Chenonceau. Also, if spending any time in Paris, the gardens at the Musee Rodin are wonderful and a great way to spend a few hours.

From a garden perspective then Villandry is definitely the recognised stand out.
http://www.chateauvillandry.fr/en/
Others to consider ...
Chenonceau http://www.chenonceau.com/index.php/en
Azay le Ferron http://www.chateau-azay-le-ferron.com/en/
Valencay http://www.chateau-valencay.fr/en/