Horticulture, n.
Etymology: [L. hortus garden + cultura culture: cf. F. horticulture. See Yard an inclosure, and Culture.]
The cultivation of a garden or orchard; the art of cultivating gardens or orchards.
Shades of meaning
Fernald has no entry of its own for horticulture; he lists it under agriculture.
Where he writes about it:
Gardening in general, kitchen-gardening, the cultivation of vegetables, etc., for the household, market-gardening, the raising of the same for sale, floriculture, the culture of flowers, and horticulture, the culture of fruits, flowers, or vegetables, are all departments of agriculture, but not strictly nor ordinarily of farming; farming is itself one department of agriculture. — from agriculture