There are over a thousand species of begonias, known to us, and not all of them are tuberous. Other categories of begonias require different care. [1] X Research source Begonia flowers range in size from half an inch to almost a foot across. They come in every color except for blue. Cascading begonia types, such as illumination begonias, are perfect for planting in hanging baskets, since they’ll grow over the edge and trail toward the ground. Upright types, like nonstop begonias, grow about a foot tall. [2] X Research source
If you live in an area where the summers tend to be particularly hot, start the begonias early enough so that they will be established before the high summer temperatures.
Use a 6-inch (15. 2 cm) pot for up to two small, 1 to 3-inch (2. 5 to 7. 6 cm)diameter bulbs or one larger bulb. Use a 10-inch (25. 4 cm) pot or basket for three small bulbs. If you’re unsure which potting soil mixture to buy, get a soilless mixture and mix it 3 parts to 1 part with builder’s sand. [3] X Research source This will provide the right drainage for begonias. Handle the tubers with care, since they may not sprout if they get bruised or damaged. Look for tiny pink buds or an old stem scar if the bulb doesn’t seem to have a hollow. They indicate the top and should face up. Make sure the pots or flats you use have drainage holes.
Keep the temperature in the room at 70 degrees or higher. A lower temperature will inhibit the tubers from sprouting. [4] X Research source If the tuber sprouts grow over two inches tall before the ground has thawed enough to plant them outside, repot them in larger pots to give them room to keep growing. You shouldn’t need anything larger than a 12-inch pot. If you plan to grow your begonias in pots, you can simply transplant them to the larger pots you’re planning to keep them in.
Your climate matter, too. If you live in a cooler area, your begonias will be able to tolerate more sun than a warmer area. If the soil is dry or doesn’t drain well, till it to a depth of about five inches and mix in compost or other organic matter to make sure the area has excellent drainage.
If you’re watering potted begonias, water until water flows from the pots drain holes, and dump any drained water that accumulates in a tray or saucer promptly. For the biggest, brightest blooms, you may also fertilize the begonias every other week with a fertilizer for blooming plants prepared according to label directions.
If you live in a hot climate, forced dormancy isn’t necessary, as the begonias will survive the winter outdoors. Trim the begonias back for the winter. They’ll begin growing again in early spring.
Digging the tubers out of the ground is not necessary if you live in a place where the ground never freezes.
