Horticulture is a nice long word for "gardening." If you study horticulture, you learn about plant propagation, soil, fertilizer — everything that makes a good garden.
The word horticulture was coined in the late 17th century — when some serious gardens were being planned and executed in England — and is based on the Latin word for "garden," hortus, combined with the suffix -culture, mostly likely in the same way as the word agriculture.