Sun Exposure: Full

Soil Type: Organically rich, loamy, well-drained but moist

Soil pH: Acidic (5.0-6.5)

Also known as million bells, calibrachoa is a prolific bloomer that never quits in a Southern summer. Calibrachoa looks like a mini petunia but is better at withstanding the heat than many petunia varieties. A slow-release fertilizer will boost its blooming even more.