There are many types of Begonias, but the Begonia Grandis is part of the tuberous family of Begonias.
It grows green heart-shaped foliage that has a red vein that runs through it. As a result, the back of their leaves is pretty when they are backlit in a garden or pot.
The blossoms are either pink or white and it blooms during the growing period which is the summer months.
The flowers are delicate and small and look great as a ground covering in a garden or in a pot.
Although the Scientific name is Begonia Grandis, they are sometimes known as Hearty Begonia.
Begonia Grandis is part of the Begoniaceae family consisting of about 1500 different species according to the North Carolina State University.
One of the most interesting things about this plant is its natural desire to propagate.
With proper Begonia Grandis care, this plant will grow tiny bulblets in the axils of its upper leaves, these bulblets drop to the ground and produce a new plant making this plant an easy one to add as a ground covering in any garden.
They are perennials and as such the winter months are dormant for these plants.
They are easy to grow plants both indoors and outdoors.
Table of Contents
Best Practices for Begonia Grandis Care
Soil
Begonia Grandis care is pretty simple. They grow well in any high-quality, fast-draining soil.
Very wet conditions can cause root rot, so you want to make sure the soil drains well.
For my Begonia Grandis care, I make sure it is in a neutral pH soil with two parts of soil and one part perlite.
I have had excellent results with this mixture. In fact, I use it for most of my indoor plants.
If I am planting my Begonia Grandis outside, I will add compost to the soil in the spring and a mulch cover in the fall.
Begonia Grandis requires well-draining soil to thrive
Light
These plants do well with partial shade but will also cope with a fully shaded area.
My Begonia Grandis care is to keep it in a mostly shaded area of the room that has no direct sunlight, however, I do leave the curtains open during the day.
Watering
The best Begonia Grandis care for watering is to water often enough that it doesn’t get dry between watering.
I stick my finger in the soil and water it when the top two inches are not quite dry but will be in another day or two.
I water it fully, allowing the excess to drain through the draining holes in the bottom of the pot and I keep the soil damp but not ever wet.
These plants can be susceptible to rhizome and stem rot as well as root rot due to overwatering.
As an example, this happened to my Begonia rex. The rhizome started to rot when I overwatered it. Therefore it is a great idea to test the soil with your index finger first and only water once the soil is only slightly wet.
Temperature
Like all of the Begonia family, Begonia Grandis prefer daily indoor temperatures of 75 degrees with a low of 60 degrees at night.
They can tolerate higher temperatures as long as they have protection from the harsh sun rays.
Humidity
Since Begonia Grandis plants are tropical and subtropical, they thrive in humid conditions.
I mist my plant’s leaves regularly but not excessively. Part of the Begonia Grandis care I would recommend is having a humidifier if you live in a very dry climate.
This has made a big difference for me in my Begonia Grandis growth.
I leave it on all year round to keep the room at around 65%. I would not recommend going lower than 50% humidity and I never let mine get higher than 75% humidity.
Fertilizer
I have found that one of the most important things in Begonia Grandis care, is composting.
I don’t fertilize it other than to add either perlite to indoor plants or compost to outdoor ones.
They grow well for me without fertilizer but if you do want to use one, use a 10-10-10 liquid fertilizer diluted to three parts water and one-part fertilizer.
Begonia Grandis prefer fertilizer poured around the base gently when they are being transplanted or once during the growing season.
Begonia Grandis Care is successful even with sparse fertilization
Propagation
Begonia Grandis will self-propagate in the pot or in a garden but if you want to relocate them or grow a second indoor plant, the easiest way to propagate a Begonia Grandis is by separating the tubulars and repotting them.
It is also possible to take cuttings from the plant to propagate.
You can also collect seeds for propagation, but it tends to be a fussy way of doing it that yields not much growth. If you want to try, you can let the pods dry directly on the plant.
Break them open and collect all the seeds that are not discolored or damaged. Clean them, dry them and then they can be stored for planting.
Growth
If you give your Begonia Grandis care, it will grow to an average size of three feet in height and width.
It takes about five years for the plant to reach its full size.
These Begonias reach an average size over the course of 5 years
Potting and repotting
I always give my Begonia Grandis a well-draining pot with enough drainage holes in the bottom.
All Begonia’s like to be root bound, so repotting is not necessary very often. It is beneficial once the roots completely fill the pot.
Repotting boosts the soil nutrients and to allow for proper aeration of the soil. Do not repot your begonia if there is still loose soil.
A pot that is too large for a Begonia will allow the soil to supply too many nutrients and too much water and it will wilt as a result.
Common Pests
The most common pests with this plant are mealy worms, mites, thrips, and whiteflies.
They can be sprayed with an insecticidal soap and water mixture to prevent these pests.
Another option for Begonia Grandis care is to wipe the leaves with neem oil.
I am also careful not to over or under water the plant as an improper watering schedule can encourage bugs.
Propagation – Let’s dive a bit deeper into the process
The best time to propagate your Begonia Grandis is when you must repot it anyway as this stresses out the plant the least.
I prefer to do it in the spring.
The first thing to do it to remove the plant from the pot and to gently shake off the excess dirt.
Sometimes if the dirt is very clumped, I’ll soak it for a few minutes in water to free the tubers.
Once the roots are exposed, you will see the tubers (bulbs). Separate them gently.
The separated clumps should grow in either soil or water with the proper Begonia Grandis care.
Simply plant them in a prepared pot with proper drainage and a rich easily draining soil or clean the soil off and put the separated plants in a vase filled with water.
If you use tap water, make sure it sits for 24 hours before doing this to remove the chlorine. I do this when I water my plants as well. Plant the tubers hollow side up.
The other option for propagation is to do it with a cutting.
I have done this successfully once or twice, but I tend to just plant the tubers when I repot if I want additional plants.
If you decide to grow new plants from cuttings, slice a few leaves from the parent plant, leaving a ½ inch to a full 1 inch of the petiole intact on each leaf.
Place the leaves in water or a mix of peat moss, vermiculite, and perlite. The cuttings should start growing roots in three or four weeks and will be ready to transplant into small pots in six or eight weeks.
As I mentioned above, this plant will propagate on its own as well. It grows tiny bulblets in the axis of it’s leaves and then they fall to the ground or into the pot and produce a new plant.
It is easy enough to repot these bulblets if you want once they have started growing.
Gently dig them out of the soil with your fingers and put them in a starter pot with equal parts peat moss, perlite, and vermiculite.
Begonia Grandis carries beautiful flowers
Tips & Tricks to keep your Begonia Grandis happy
When you are giving your Begonia Grandis care, a good thing to remember is the humidity levels.
I find that my plant flourishes when I have a humidifier in the room with it all year round although I do adjust it to be slightly more humid in the winter.
Another way to get more moisture into a new cutting is to drape a plastic bag over the cup or pot in the shape of a tent to hold the moisture in until the roots are growing if it is a newly propagated plant.
I keep all my high humidity plants in one room, and I mist them every second day.
I also keep the door closed to make sure that all the humidity stays with the plants.
Don’t repot them often.
I have found that my Begonia Grandis struggle a bit when I do repot them, so I wait until the pot is full of roots with not one inch to spare.
If there is even an inch of extra room in the pot, hold off until it has grown that extra inch.
When you are repotting it, use a pot one size bigger than the last one, as it will not grow well if there is more than an inch or so of room in the pot.
I repotted mine into a pot that was two inches bigger once and it wilted and struggled after the repotting.
I thought for sure it would die but I did manage to save it in the end.
Commonly asked questions regarding the Begonia Grandis plant
Where can I buy a Begonia Grandis plant?
You don’t have to make any special trips for this plant. They are available regularly at garden and home gardening stores. I have also seen them at grocery stores and even on Amazon.
Does my Begonia Grandis care need to include regular pruning?
It is a good idea to deadhead the flowers from the plant as needed to encourage new growth and to prevent the plant from using its resources on a dead bloom.
Are Begonia Grandis plants toxic to animals?
Yes. They can cause burning and swelling of an animal’s mouth and lips and throat making it difficult for the animal to breathe. I keep mine in a closed-off room away from my pets.
Can I plant Begonia Grandis in my outdoor garden if I live in a colder climate?
Yes, but once the dormant time comes, make sure to mark where the tubers are planted for the following year.
Conclusion
Begonia Grandis is one of the easiest Begonias to grow and maintain.
They don’t require much to grow well, and they are self-propagating which makes them an inexpensive ground covering for an outdoor garden.
They prefer the shade and require a damp, but not wet, environment.
Begonia Grandis prefer to be rootbound and as such don’t need to be repotted much and as long as they are in a well-draining pot with rich, well-draining soil they will thrive.
They produce delicate flowers in the summer which should be deadheaded periodically to encourage new growth.
For proper Begonia Grandis care, remember to mist the leaves regularly, especially if you live in a dry environment.
They also do very well with a humidifier in the room or in a greenhouse where it is naturally humid.
Just be sure to keep them in partial shade or their delicate foliage will get burnt and die.
Overall, these are an easy plant to care for that look delightful in a garden or in a pot.
I have even grown them in larger containers as an accent piece to my greenhouse with great results.
They are pretty and delicate and when they bloom, they turn any area into a beautiful focal point of white and pink.
What is your favorite Begonia? Other popular Begonia species are Begonia Maculata and Begonia Pavonina.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.