Fecund [ˈfe-kənd, ˈfē-kənd]
1. Fruitful in offspring or vegetation, prolific
2. Intellectually productive or inventive to a marked degree

● Usage:
In the Northwest, summer is short and sweet, with picture-perfect sunny days, hot but not broiling temperatures, fecund gardens, and fewer mosquitoes and bugs than other regions.
Here was one of her fecund mind’s most enduring creations.

First known use: late 14th century. Came to late Middle English from Latin 'fēcundus' - 'fertile' and from Middle French 'fécond' - 'fruitful'.
Fecund and its synonyms 'fruitful' and 'fertile' all mean producing or capable of producing offspring or fruit-literally or figuratively. 'Fecund' applies to things that yield offspring, fruit, or results in abundance or with rapidity ('a fecund herd'; 'a fecund imagination').
'Fruitful' emphasizes abundance, too, and often adds the implication that the results attained are desirable or useful ('fruitful plains'; 'a fruitful discussion').
'Fertile' implies the power to reproduce ('a fertile woman') or the power to assist in reproduction, growth, or development ('fertile soil'; 'a fertile climate for artists').