Begonias vary in color and size and are beloved for both their showy foliage and flowers. Begonias bloom in shades of white, yellow, orange, pink and red flowers. Tuberous or “wax” begonias (Begonia x semperflorens-cultorum and B. x tuberhybrida) produce large flowers that can grow up to 6 inches in diameter. Often grown in containers indoors, begonias also can be grown outdoors during the frost-free months. If you live in a region that doesn’t experience freezing winter temperatures or frosts, keep the begonia tubers in the ground year-round.
Select a planting site for your begonias in partial shade. Choose a location with soil that drains well and doesn’t become waterlogged.
Spread a 1- to 2-inch-thick layer of peat moss or organic compost onto the planting bed. Mix the organic matter down into the soil to a depth of 8 to 10 inches. Also mix into the soil an all-purpose plant fertilizer, such as a 10-10-10 NPK formula, at a rate of 1 pound per 100 square feet of planting bed.
Dig planting holes for your begonias the same depth and width of the nursery containers, spacing the holes at least 12 to 18 inches apart. Remove the begonias from the nursery containers and plant them at the same depth as they were planted in the containers.
Water your begonias deeply and thoroughly once or twice each week during summer when rainfall is less than 1 inch. Keep the soil evenly moistened, but allow the topmost layer of soil to become dry to the touch before watering.
Feed your outdoor begonias with 1 pound of a 10-10-10 NPK formula fertilizer per 100 square feet of bed once each month from spring until early autumn.
Dig up the begonia tubers after the first frost in fall. Cut off and remove all the foliage and set the tubers in a shady spot to dry for about two or three days. Store the tubers during the winter months in a paper bag filled with dry peat moss or sawdust. Keep air temperatures at about 50 degrees F.