Table of Contents
What is a Begonia Grandis (Hardy Begonia)?
Begonia Grandis, also known as the Hardy Begonia or Shukaidou, is native to Japan and Southern China.
It is a herbaceous begonia species that grows to about 2 feet tall.
This plant is rarely kept indoors and thrives in shady areas with organically rich soils similar to ferns and hostas.
Here, it will thrive and reproduce until large colonies of plants have formed.
The leaves of the Begonia Grandis are olive green with colorful undersides. They have either pink or white flowers and simple, eye-catching foliage.
While the standard Grandis begonia is popular, variations like the Begonia Grandis subspecies Evansiana and Evansiana Alba are very popular for gardens looking for something with a slightly different look.
If you are a fan of pollinators like bees, having these in your shade garden is sure to bring your pollinator garden to the next level.
How to Care for Begonia Grandis
Begonia grandis are lovely, easy-to-grow plants that can enhance the beauty of any garden.
They require little attention and prefer to be kept in a warm, well-lit environment with plenty of water.
If you have a Begonia grandis plant, keep reading for tips on how to care for it.
Temperature and Climate
Hardy begonias are cold-tolerant and thrive in USDA hardiness zones 6 and 7.
They are so hardy, that they can handle temperatures below freezing – down to 23 degrees Fahrenheit.
They are perennials, and this plant type dies off in the winter and comes back each year in the spring.
These plants appreciate a blanket of mulch to keep their bulbs warm in the cold season.
It is good to refresh your begonia beds each fall by removing last year’s mulch, adding a layer of compost, and then covering them with a new layer of mulch.
Light
Hardy begonias prefer to be planted in a shade garden and are good companions to ferns and hostas.
A woodland garden with lots of trees and full shade is where this plant will grow the best, but partial shade is acceptable.
In shady areas, it will thrive and provide your garden with beautiful foliage in the spring and a stunning bloom in the summer and fall.
Watering
Water Hardy begonias frequently enough so that they do not dry out between waterings.
The Begonia grandis appreciates being moist, so you need to water them regularly.
The best way to tell if your begonia is ready to be watered is to stick your finger about an inch into the soil.
If you find your finger close to being dry, you can water your begonia again.
Don’t let the plant completely dry out, or its roots could suffer.
Soil
Begonia grandis does well in various soils, but its preference is rich, moist, and well-drained.
If your ground soil doesn’t quite measure up to that, you can always mix some good-quality soil into the ground and go from there.
You can even mix some compost into your potting soil. They will grow much better in peat-based compost than in soil. This is because compost keeps soil moist and adds nutrients.
If you find that the soil retains too much water, add some soil amendments like perlite so the soil drains better.
Fertilizer
Fertilizer is not necessary for Begonia grandis plants.
A better option is to add compost to your soil and then cover the soil in mulch in the winter.
Hardy begonias can thrive with the natural nutrients in the soil.
Common Pests
Begonia grandis plants are pretty resistant to common pests. They
True to its name, the hardy begonia is resistant to most pests that would try to eat its foliage.
With that said, some of the common pests that infest Begonia grandis include mealy worms, mites, thrips, and whiteflies.
To keep these pests at bay, spray them with an insecticidal soap and water mixture. Wiping the leaves with neem oil is another option for Begonia Grandis care.
Other disease-like issues to be aware of are mildew and mold on the leaves.
If you notice mold, try to stop watering the leaves. Let the sun dry the water off, and the mold and mildew should resolve themselves.
Repotting
The best time to repot Begonia grandis is in the spring. Don’t repot them during the winter as they are dormant during this time of year.
If you decide to keep your begonia as a container plant, you must use well-drained soil and a pot with good drainage, as one of the most significant risks to these plants is root rot and mildew.
You will want to separate your parent plant from the new babies and give each room to grow into its own bushy mound.
Propagation
Begoinia grandis self-propagates by dropping bulbils that form in the leaf axils or seeds.
Unlike some other begonias, these are not propagated through cuttings.
The bulbils will fall to the ground in early fall and stay dormant until spring.
You can also grow this plant successfully from seed.
Seeds will create a more genetically diverse group of plants, and the bulbils will produce genetically identical plants to their parents.
If you live in USDA hardiness zones 1–5, you can collect the bulbs after they fall in the autumn and winter them inside until next spring.
Pruning
Begonia grandis plants do not need much pruning.
However, it is recommended that you deadhead the pink and white flowers to encourage new growth and more blooms.
If you wish to do more pruning, you can trim back your plants to a shape that pleases.
Avoid cutting off pendent clusters of new blooms or cutting too much off as this will stress the plant.
FAQ
Is Begonia grandis invasive?
No, Begonia grandis is not invasive. However, they grow and spread very quickly once planted. If you find grow in an area that you don’t want them to be in, simply replant or weed them out.
How do you care for Begonia grandis?
Begonia grandis are relatively easy to care for. They prefer full shade and dislike direct sunlight, so pick a good place in your garden for them to go. They do well in groups, so if you can, it’s best to start with several plants and then let them fill in from there. Water regularly and be sure to deadhead old flowers.
Do hardy begonias spread?
Yes, Hardy begonias do spread because they self-propagate. They drop bulbils from their leaf axils. This can cause the plants to grow and spread further than you intend to in your garden.
Conclusion
The hardy begonia is a beautiful species that is relatively easy to care for.
With beautiful heart-shaped leaves and white or pink flowers, it is sure to add flair to your backyard shade garden.
Avoid direct sun, and you will enjoy a long bloom time from late summer through the fall.
With obliquely ovate leaves that have beautiful red veining and pink flowers, it’s easy to see why they are a popular choice for a garden.
Other Types of Begonias to Consider
There are many types of begonias to think about when choosing a plant for your home or garden.
For example, cane begonias have tall, tuberous begonias are small, compact plants used for bedding or fibrous begonia for their flashy blooms.
There are many other types of Begonias to grow in your garden.
References
Lindsey Hyland grew up in Arizona where she studied at the University of Arizona’s Controlled Environment Agriculture Center. She continued her gardening education by working on organic farms in both rural and urban settings. She started UrbanOrganicYield.com to share gardening tips and tactics. She’s happy to talk about succulents and houseplants or vegetables and herbs – or just about anything in a backyard garden or hydroponics garden.