An easy favorite here in Yuma, popcorn cassia fills up the air every summer and fall with the rich buttery scent of lightly burnt popcorn. Growing up to 8 feet in one year it will provide a full season of blooms even in the first year. It is very tolerant of poor soils. Height: 6-8′ tall and wide. Hardiness: 9a-11 Flower Color: yellow Characteristics: Quick growing upright shrub or tree that bears stems of yellow strongly scented flowers all through summer and fall.