Beginner’s Guide to the Tuberous Begonia

Updated October 5, 2021
Begonia Tuberhybrida

Picture a hanging basket overflowing with full, double blooms or a garden bed that just seems to be a riot of color all summer long. It's not just a dream - tuberous begonias can make it a reality, and no matter what style of garden you have, you're sure to find a variety you'll love.

Growing Tuberous Begonias in Your Garden

Unlike other kinds of begonias, tuberous begonias grow from tubers. While they're generally grown for their flowers, there are several varieties that also have interesting foliage, providing color and beauty even when the plant isn't in bloom.

The flowers of tuberous begonias are full, double, and almost rose-like in shape. They bloom in just about every shade except blue, and some varieties are even fragrant.

Tuberous begonias are phototropic, which means that both flowering and dormancy periods are triggered by day length. They will begin to flower when day length reaches 12 hours a day.

Where to Plant Tuberous Begonias: Light and Soil Requirements

These plants are not fussy about soil type or pH levels. They will thrive in any good garden soil that has been amended with compost or composted manure. If you're growing in containers, a good, all-purpose potting mix is all they need.

Tuberous begonias thrive in light or dappled shade. They do not do well in full sun. They are easily damaged by wind or heavy rain, so they should be planted in a sheltered location.

Watering and Fertilizing

Good drainage is essential! Raised garden beds or those positioned so that water drains away from the bed are good choices. If you're growing tuberous begonias in containers, make sure there are plenty of drainage holes and add small stones to the bottom of the container to improve drainage even more.

These plants flower heavily while storing nutrition in their tubers for future growth, so they are heavy feeders. Give them a feeding of a balanced fertilizer early in the season to promote plant growth and consider feeding with a bloom-promoting fertilizer later in the season when flower buds form.

Tuberous begonias characteristics

Pruning Tuberous Begonias

Many growers remove the first buds, which delays flowering but encourages larger flowers. You do not need to deadhead tuberous begonias - they self-clean, dropping their faded blooms within a day or two, and will keep blooming away.

Tuberous Begonia Pests and Diseases

Tuberous begonias are sometimes attacked by aphids, spider mites, and whiteflies. These pests can be controlled by beneficial insect predators or using insecticidal soap. Check them regularly to make sure the infestation is under control and spray again in a week or two if you're still seeing signs of insects or damage.

Powdery mildew is occasionally a problem. The best control is to increase air circulation and avoid overhead watering. Fungicides can be used if required.

Propagating Tuberous Begonias

You can increase your tuberous begonias by cutting the tubers into sections with a sharp knife before potting them. Be sure each section has a bud. Treat each section as if it were a complete tuber.

Tuberous begonias can also be started from seed, but you'll have to start them very early, often in December in most zones for summer blooms.

Storing Begonia Tubers for Next Year

You can store your begonia tubers to use next year, as long as you follow a simple process.

Caring for Begonia Tubers in the Fall

These begonias begin to go dormant when day length shortens in the autumn. When they start turning yellow and dropping leaves, gradually limit water to stimulate dormancy.

  • In frost-free climates, tubers can be left in the ground or in their pots all winter as long as the soil is dry. The tubers are vulnerable to rot, so if the soil will be wet, it will be necessary to lift and store the tubers.
  • In cold areas, freezing weather will destroy the tubers, so they must be lifted and stored each fall. Store them in a cool, dry place. Container-grown begonias can even be stored right in their pot, as long as it's stored in a frost-free, dry place all winter.

Starting Spring Growth

The tubers should be started into growth in late winter. This is a fairly simple process.

  1. Move the tubers from their cool storage area to a warmer place until they begin to sprout.
  2. Once the sprouts are visible, the tubers are ready to plant. Use a light soil that contains no fertilizer.
  3. Bury each tuber completely; the roots develop from the tops and sides of the tubers.
  4. Water lightly, being sure the soil drains well. It should be evenly moist but not wet.
  5. Place the potted tuber in an area that receives filtered sunlight and has an average temperature of 60 to 70 degrees Fahrenheit. Water only when the surface of the soil is rather dry. They can be repotted as needed.
  6. Tuberous begonias can be moved outside or bedded out after the last frost. If you are bedding out, bury each tuber at the same depth it had in the pot.

Beautiful Tuberous Begonias to Grow in Your Garden

There are hundreds of varieties of begonias, and you're sure to be able to find a color and flower style that suits your garden perfectly. With that in mind, here are just a few of the many, many possibilities for begonias you might want to grow.

Solenia Cherry

'Solenia Cherry' tuberous begonias have full, double blooms that reach about three inches in diameter and are a rich, bright red. It grows to 10 to 12 inches tall and wide and has a mounding, upright growth habit.

Go-Go Yellow

Begonia yellow flowers closeup

'Go-Go Yellow' has vibrant yellow semi-double blooms that just seem to keep forming and blooming nonstop all summer long. It has dark green foliage, which makes the bright blooms pop even more. 'Go-Go Yellow' grows to about eight to 10 inches tall and wide, making it a good option for pots, hanging baskets, or the edges of garden beds.

Whispers

'Whispers' is a stunning creamy white-flowered begonia that has enormous double blooms that can measure up to eight inches in diameter. 'Whispers' grows to 24 to 30 inches tall. A single tuber in a large container would make a perfect display, but this variety also looks wonderful in garden beds.

Bouton de Rose

Bouton de Rose Begonia

'Bouton de Rose' is a unique begonia that has pale pink double blooms, each petal edged in deeper pink. The deep green leaves provide the perfect backdrop for the showy flowers, which bloom prolifically from early summer until frost. 'Bouton de Rose' grows to 10 to 12 inches wide and tall and is wonderful planted in a hanging basket or container.

Nonstop Fire

Nonstop Fire Begonia

'Nonstop Fire' is not for the tame of heart or those who enjoy understated plants. The blooms of this tuberous begonia are a cacophony of colors, a blend of pinks, yellows, and coral that looks almost like a summer sunrise. The flowers are four inches in diameter, and the plants grow to about ten inches tall and wide.

Nonstop Blooms, Easy Care

Tuberous begonias will provide gorgeous color all summer long with very little maintenance. Whether you enjoy softer tones or vibrant ones and whether you're looking for a mass bedding plant or a container specimen, there's certain to be at least one variety of begonia out there that's perfect for your garden.

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Beginner’s Guide to the Tuberous Begonia