Indoor Plants

• 1). Choose a pot or planter that is 4 to 6 inches across and has a hole in the bottom. Plant the yellow begonia in a soil that is a mixture of peat moss, sand and garden soil. Make sure the roots, but not the greenery, are completely covered in soil.
  
  
• 2). Water your yellow begonia from the bottom up. Set the pot or planter in a bowl of water or sink filled with 1 to 2 inches of water for one hour. Soaking the water up through the hole in the bottom of the planter will help more water get to the roots and decrease chances of rot to the plant's greenery. Allow the plant to dry out for a day or two between waterings to prevent oversaturation.
  
  
• 3). Set your plant in a spot where it will get a low amount of sunlight. Yellow begonias require partial sun to partial shade.
  
  
• 4). Feed your begonia with a commercial plant food. Check the label to ensure the food can be used with begonias and feed according to the manufacturer's instructions. This will replace nutrients lost to being indoors.
  
  
• 5). Remove dead leaves and flowers immediately. Remove any dead leaves or flowers that may have fallen into the soil.
  
  
• 6). Check for diseases or decaying periodically. Look for powdery mildew, which is common in yellow begonias.
  
  
• 7). Transplant your yellow begonia to an outside spot in the summer months to help it thrive.
  
  

Outdoor Plants

• 1). Wait until early June or until the last frost of the winter has passed to plant your yellow begonia.
  
  
• 2). Pick an outside spot that is partially shaded, and partially in the sun. Dig a hole at least 2 inches deep with your garden spade and plant your yellow begonia, ensuring the roots are completely covered in soil.
  
  
• 3). Water your yellow begonia at ground level. Avoid getting water on the flowers and leaves, as excessive water to the greenery may lead to rot.
  
  
• 4). Water your begonia only when there are long periods between rainfalls. Yellow begonias require normal to dry environments.
  
  
• 5). Space begonias 12 to 14 inches apart if you wish to plant more than one.
  
  
• 6). Dig up your yellow begonia, plant it in a pot and bring it inside before the first frost if you want it to survive the winter.