Basho's haiku are filled with references to nature and cultivated lands, of course, which may qualify as one source of growth. In the poems, we come across frogs in ponds, scarecrows in rice-paddies, baby mice in their nest, and so on.
The poems are also filled with references to people (in different stages of life) at work, rest, or devotion within that natural world. We come across children husking rice, field hands taking a nap, and so on. Could family or community be a second source of growth?
In any case, to me (only a casual reader of the haiku!), the poems seem more focused on the speaker's impending death than on growth. There's a lot of end-of-life imagery: autumnal settings, graveyards and crematoria, and so on.