Canna is one of the most popular tropical foliage plant used in gardening. And 'Pretoria' foliage is gorgeous. It has light green glossy leaves with striking bands of white, cream and yellow.
Canna can be planted anytime of the year in southern zones but the soil temperature should be 78-80° F. In zones 3-8, plant in spring and summer when ground temperature is not below 65°F. They should be started indoors one month prior to moving outside. Canna prefer a sunny location in moist, fertile soil. When planting outside, prepare soil by spading and adding compost or rotted manure. Rhizomes should be planted 1 - 1/2" deep and spaced 18-24" apart. Soak well after planting. For container planting, pot one rhizome per gallon in well drained potting mix. Containers will finish in 10-12 weeks when potted during the appropriate temperatures: Daytime 70-75° F; Night 65-70° F. Fertilize established (2-3 weeks) plants monthly with 1:2:1 ratio (12:24:12 or 5:10:5), fertilizing at 1/2 the package recommendation. NPK at 200 ppm weekly in injector fed systems.