Which of these plants ("Endless Summer" or "Forever Pink") is going to provide the reddest, longest-flowering blooms in the Atanta area? What do we add to this acidic soil to make sure these bloom red (or pink)? How often do we need to add it? Thanks.
Endless Summer vs. Forever Pink
You'll want the Endless Summer Radiant Red cultivar, it's a red as opposed to a pink (I have it). I think Forever Pink will be just that, pink. But let's hear from the real hyd experts (I am a rank amateur!) about colors. I bought RR on a whim late in the season and planted near my quince where the soil is kind of acidic.
You'll need lime to "sweeten" the soil. If you don't, it may turn bluish.
Don't add too much lime at once. It takes six months for lime to begin to work so patience is required......unfortunately.