In a nutshell

breed all Minecraft flowers (vanilla flowers)
additional plants and flowers
proper stems, blooms and also recipes
craft new flowers from stems and blooms

Pictures

New Flowers and Plants

(only available when Growing Flowers Plus activated)

(only available when Growing Flowers Extended activated)

How to breed Flowers?

hoe a dirt block
craft seeds using 2 flowers
plant these seeds on hoed land
let them grow
when looking like normal flowers, crop them (drops 1-4 flower(s) and 1-3 seed(s))

if cropped too early, it drops only seeds
use a shear to get blooms and stems
growing to slow? Use bonemeal!

Recipes

Shown all here

The following are only available when the Option "Growing Flowers Plus" ist activated

The following are only available when the Option "Growing Flowers Extended" ist activated

How to activate "Growing Flowers Plus" or "Growing Flowers Extended"?

Both are normally deactivated. Before starting your World, go to "Mods", select "Growing Flowers" at the Mods list. The press "Config" at the bottom left corner and activate Plus or/and Extended. Mention, that the Recipes of "Growing Flowers Extended" needs "Growing Flowers Plus" to work!

Credits

Code and realisation: me (gelber_kaktus, also known as Yelteen)
Textures (plants, flowers): juirox
Textures (seeds) ced_der and Dragonisser