The gardenia is an evergreen shrub with dark green, glossy, oval leaves and waxy blooms that range from pale yellow to creamy white. It thrives outdoors and can get up to six feet tall depending on the species. You may want to plant one near a window or patio to fill the air with its intoxicating scent. Taking care of gardenias is simple as long as you remember the basics of gardenia plant care: well-drained, acidic soil and adequate fertilization