Begonias are one of the largest plant families, with over 1,500 named species, according to the American Begonia Society. Proper bulb care is a crucial factor in the health of your begonia plants. Remove the foliage only after it has given its nutrients to the bulb and store those precious bulbs out of reach of hungry rodents.
When frost begins to blacken the tips of your begonia plant it is time to dig up the bulbs. Carefully remove the bulbs from the soil, along with any offsets that may have grown.
Allow the foliage of your begonia plants to remain attached to the bulb when digging them up. The foliage will dry out on its own, giving its nutrients back to the bulb as it withers. When the foliage has dried completely, pinch it off.
Begonia bulbs winter best when stored in a cool, dry place between 45 and 50 degrees Fahrenheit. Since most bulbs make great food for rodents, choose a pest-free storage area for you bulbs. Include sphagnum peat or vermiculite with your begonia bulbs for optimal storage conditions.
Once the risk of frost is gone, plant your begonia bulbs. Begonias need at least partial shade and require more shade in hotter climates. Loosen the soil and place bulbs, indented side up, into the soil. Keep the bulbs shallow and do not cover completely with soil. Begonia bulbs should be planted 15 to 18 inches apart from each other and watered thoroughly after planting.
To enjoy your begonias inside, pinch blooms from the stem and let them float in a large bowl of water. Keep as much of the foliage attached to the plant as possible, as the foliage is what provides the bulb with the nourishment it needs to make it through the next winter storage.