Scarlet Begonia Care InfographicScarlet Begonia produces a very heavy bloom around a unique shade of red. These flowers will surely give red roses a run for their money. Even without flowers, the foliage of this plant still looks esthetic enough.

Read through our guide to learn how to keep this plant thriving ad blooming.

What Is Scarlet Begonia?

Scarlet Begonias are evergreen plants that are known for their long bamboo-like stems. These stems can grow up to one meter tall and grow leaves that measure four to six inches. From summer till frost, they produce the most gorgeous and heavy blooms that are a deep scarlet in color.

Scarlet Begonia Care

Scarlet begonias care requires you to put these plants in bright indirect light when the temperatures are hot and direct light when temperatures are lower.

The soil should be a perfect balance of sandy or loamy with monthly fertilizing. 70 to 75 degrees during daylight hours and above 60 degrees at night are ideal temperatures for this plant throughout the year.

Below, we have discussed each care requirement in separate sections.

– Water Requirements 

Watering Begonias is tricky as this plant needs neither too much nor too little water. During summer, you will have to water every second to the fourth day, but only if the soil dries up about 75 percent.

Take a moderate quantity of water, preferably in a bucket or a slow pressure hose, and pour it on the soil. Avoid watering the plant itself because this can lead to attacks by fungi or bacteria.

You need to water the plant sort of slowly with a steady hand. This allows the water enough time to go through the whole soil properly. When this water begins to drain out of the pot, the soil has been thoroughly watered.

You should ensure that the soil is 75 percent dry from top to bottom before you can water it. The easiest way is to push any thin stick down the soil. When it comes out dry about one-third of the way, only then it’s safe to water.

A moisture meter can determine the most accurate measure of the soil’s moisture levels. It is similarly inserted in the soil and tells you how dry or moist your soil is. A reading below 5 means that the Begonia is now ready to be watered.

Begonias belong to USDA hardiness zone 3 to 9, making them a plant that can survive tap water. However, we suggest you go for rainwater or filtered water for the best results. We always use water filtered through reverse osmosis.

Using tap water for a long time leads to salt and minerals in the soil. The soil takes up these salts along with water. When this water evaporates during plant ventilation, the salts are left behind on the leaf surface.

Scarlet Wax Begonia Plant

– Light Requirements

Depending on the temperature, this plant needs bright, direct, or indirect sunlight. In either case, it will not bloom if the light conditions are constantly low. 

During summer, try to provide it with some shade. If it is outside, then move them under a tray, maybe. Within a room, too, you need to keep it away from direct light coming from the window. This is especially important if the window in question faces the south.

During spring, fall, and winter, when temperatures are relatively lower, Begonias tolerate direct light too. You can put them on a shelf, patio, or yard. The southern, eastern, and western-facing windows provide bright enough light to sustain its light needs.

If you are growing this plant indoors where there is no natural light, don’t worry. The market has plenty of artificial grow lights for plants that you can use instead. They work just as well as natural light, although you will have to turn them on twice the duration of natural light

You have the option of using LED lights or fluorescent grow lights. Both have their own merits and demerits. Fluorescent lights can be a little bit costly and also tend to produce heat.

On the other hand, LED lights are cheaper, have a reasonable running cost, and do not provide much heat. It is best to install the overhead so that all sides of the plant get a uniform amount of light.

– Soil Requirements 

All begonias grow the best in soil that is loamy yet sandy. It can either be alkaline or acidic; it doesn’t matter. Try that the pH of the soil remains within a range of 6.1 to 7.5. 

Start with any ordinary potting mix that is fast draining so that waterlogging doesn’t take place within it. You can improve the drainage further by adding stuff like perlite, bark, and coco coir by yourself.

This potting medium also needs to have a sizable percentage of organic matter. You can take peat moss, manure, and compost and mix them with the soil. The addition of gravel at the bottom of the pot also helps with drainage.

– Temperature Requirements 

The ideal temperature range for this plant is 70 to 75 degrees Fahrenheit during the daytime. During the nighttime, the temperature can drop down to 60 degrees. This drop in temperature is important during the bloom season for flowering. 

104 degrees Fahrenheit is the only limit after which your plant will begin to die of overheating. Similarly, it would be best to proceed with care if temperatures don’t drop below 50 degrees in any case. In our experience, begonias tend mostly to suffer from frost shock.

Here are some of our time-tested methods to ensure temperatures around our Begonia are optimal.

  • During summer, you can keep the windows open at night to stimulate the required drop in temperature from day to night.
  • Inside a room, keep Begonias at a respectable distance from cold air vents.
  • Begonias grown outdoors should ideally be transported indoors when temperatures drop below 50.
  • If this move is inconvenient, then at the very least, cover your plant with a tarp or sheet during the whole winter season.
  • Regular watering is an absolute must if you live someplace that experiences very hot summers. Dry plants are more at risk of heartburn. Similarly, move your Begonia away from direct sunlight.

– Humidity Requirements 

The humidity needs of the Begonia scarlet also depend on the temperature outside. It will need humidity as high as 90 to 95 percent during summer to thrive. Whereas in winter, a very moderate amount of humidity, up to 50 or 60 percent, will be sufficient.

Find out to create humidity levels up to 90 percent you may start by getting into the habit of regularly misting your Begonia. We mean a very gentle misting twice or thrice a week, preferably during morning time.

Furthermore, you may place a pebble and water-filled humidity tray under the pot to add humidity and esthetics. Keep an eye out that the pot doesn’t touch the water underneath.

Another step concerning the humidity would be moving the plant to the kitchen, washroom, or laundry room also helps. These are usually the most humid and warm rooms in any house.

Furthermore, investing in a humidifier is the best thing for humidity-loving plants. It is not costly and will take your mind off maintaining the right levels. The newer ones in the market are automatic, so they will turn on and off depending on the air moisture levels of your house.

– Fertilizer Requirements 

It is important to be mindful about the fertilization of this plant since you will need to fertilize this plant every month during the growth and flowering. This period approximately lasts from spring each year till fall. You can learn what some fertilizer options for you are.

Purchase a liquid fertilizer composed of mild formulations for Begonias. Then proceed to dilute it by mixing it with water first. Then pour it over the soil but not before watering the soil thoroughly first. They will need to be used every four weeks during the period mentioned above.

Pellet fertilizers are easier to use because they must be applied only once or twice a growing season. They come in round solid pellets. Water your soil first, and then bury them halfway into the soil. They will slowly disintegrate and then release their nutrients into the soil over time.

– Pruning Requirements 

Grooming is important for your Begonia if you want to keep it in shape. Trimming its stems once or twice during the growth period will further promote more growth.

After the flowering season, snip off all the flowers and place them in a vase. This phenomenon is called deadheading, it may look like it will be impossible to rebloom, but don’t worry it will cause an even bloom the next time.

As for the pruning from another perspective, you may want to inspect your plant carefully from all sides. All old, discolored, and papery leaves need to be removed. You can then place these leaves on the soil as mulch material.



Propagation saves you from buying the same plant ever again. You can give all your peers their begonia scarlets as well. Give the two main methods below a read to see which one you like best.

– Learn Stem Cutting Propagation

Find out how to carry out stem cutting propagation in a few simple steps below.

  1. Take a Begonia scarlet stem part with no flowers growing on it. It should not be more than four to five inches long and must contain one or two leaf nodes.
  2. You can remove the leaves as they are not needed. Apply small amounts of rooting hormone to the stem end that was cut. It will help with regrowth and fighting off bacteria.
  3. Prepare a tiny spot with the Begonia potting soil and dig a three-inch hole in the center. Insert your cutting in this hole with the cut end going down.
  4. Cover the plant pot using plastic wrap to increase humidity. This is much needed during the initial days of stem cutting propagation. Every second day, remove this wrap for a couple of hours so the plant can breathe. Alternatively, you can make tiny holes in it, so the plant doesn’t suffocate entirely.
  5. The pot should be placed somewhere warm that is indirectly lit by sunlight. Give the cutting five to six weeks before it sprouts new shoots.

– Learn How To Propagate From Seeds

It takes time, but seed propagation is a great method to get new begonia scarlets. You can collect the seeds from flowers themselves or order some online. It would help if you had many seeds because only a few will germinate.

  1. You need to mix the seeds of this plant with fine sand first. 
  2. Take a shallow seedling tray and fill it with the same potting mix used for an adult plant.
  3. First, moisten the soil mix with water so that it is only slightly moist but not runny with water.
  4. Then sprinkle the sand and seed mix over the tray. You don’t have to bury them. Again sprinkle some water on top.
  5. Move the seedling tray to a brightly lit room and keep it moist. Provide heat to the seedling tray using a seedling heat mat so that it stays warm during the night.           
  6. Again, cover the tray with a transparent sheet or tray covering to amp up the humidity. This is important for germination to occur.            


Begonias are prone to a specially bad fungal infection called botrytis. They might also suffer from a random mealybug or aphid infestation. As a loving plant parent, you must find out how to identify and treat all these potential problems, in order to keep the healthy life of your plant.

– Botrytis

This is one of the nastiest fungal infections among Begonia plants. Like most fungal diseases, they attack a plant that has constantly runny soil or is wet. The plant parts that are affected the most are the flowers.

Flower petals will become swollen and develop rot. Rot also appears on the stem and underground tubers. Leaves might develop several discolored spots on their upper surface.

Botrytis spores quickly jump from one plant to the next, spreading the infection. They also cause allergic pneumonia in susceptible humans.

If the plant has been severely affected, we suggest simply removing it by burning it off. An infected plant should never be used as compost or mulch. If you think the plant can be saved, take gardening shears and cut the rotten parts off. Next, start a weekly antifungal spray regime to get rid of every last fungal spore. 

A liquid copper spray is our recommendation. Do follow the instructions given on the label during use.

– Bacterial Leaf Spot Disease

When the Begonia plant is overwatered, it can get infected by Xanthomonas campestris. This bacterium causes the highly destructive bacterial leaf spot disease. If not treated immediately, it can kill your plant in a couple of weeks.

As soon as the plant is affected, damp black spots develop all over the plant. Eventually, these spots necrose in the middle and develop holes. Leaves become limp, droop and then start falling alarmingly.

To get rid of this disease:

  1. Cut off all the parts that have blackened.
  2. Include the roots in the cutting process too.
  3. Apply antifungal sprays like liquid copper every week as it also works as a bactericidal agent.

– Mealybugs

Mealybugs are the bane of all begonia farmers’ existence. These are small white-colored insects resembling balls of cotton. As slow-moving pests, they are hard to miss for an observant plant parent.

Note that you will notice that your leaves seem covered with a sticky substance. This is called honeydew and is a classic indication of mealybug infestation. Honeydew is digestive juice secreted by these pests.

It is important to recognize this problem early on and treat it. Otherwise, your plant will begin to deteriorate and slow down in growth slowly. Your leaves will develop yellow spots and becomes listless.

Treating mealybugs is easier compared to other similar sap-sucking pests. This is because they can be easily seen and spotted. Follow the steps below to make them get off your plant.

  1. Take a hose and gently wash the plant starting from top to bottom. The underside of the leaves is an important spot not to be missed. Most of the crawling adult mealybugs will simply flow off as a result.
  2. Next, it’s time to combat the larvae of these bugs. Neem oil is a natural ingredient that doubles as an antifungal and insecticidal agent. Apply a few drops of neem oil to the leaves weekly on a schedule for at least three to four consecutive weeks.
  3. If neem oil is hard to come by, you can use a mixture of milk and water instead. Mix 20 percent milk with 80 percent water and use a spray bottle on your plant.

– Aphids

Aphids are as common as mealybugs among begonias. The fact that they cannot be seen easily makes them more dangerous.

An aphid infestation can only be spotted once it has started affecting the leaves. The plant becomes weak as a result of which, and its leaves start turning yellow. Some leaves might even begin to curl around the edges.

The most devastating consequence comes in the form of reduced flower yield. Sometimes the plant fails to flower at all. To spot aphids, you may use a magnifying glass.

Consistency is key when it comes to bidding farewell to aphids. Use the following remedies to make your plant healthy again.

  1. You must begin by washing the plant so that most of the aphid population is washed off.
  2. Neem oil is as effective against aphids as any other pest. Apply a few drops through a Q-tip on the leaves’ undersides and stem sheaths.
  3. Common household alcohol like 70 percent isopropyl will kill aphids and their larvae. Dilute it a bit by adding water and then spray on the plant. Spray every week for about a month as a prophylactic measure.
  4. You will find a lot of aphid-killing chemical insecticides on the market. They are quite effective, too, especially if you don’t have time for natural remedies.

Scarlet Wax Begonia


What is the lowest night temperature for Scarlet Begonia?

The lowest night temperature for Scarlet Begonia is typically around 50-55°F.

Can Scarlet Begonia tolerate high heat?

Yes, Scarlet Begonia can tolerate high heat. However, it’s important to provide shade and adequate watering to help them thrive in hot weather conditions.

Does Scarlet Begonia grow in winter or summer?

Scarlet Begonia primarily grows during the summer season, as it prefers warmer temperatures. It may struggle to grow during winter due to colder temperatures.


This is the end of this comprehensive begonia care article which calls for a recapitulation.

  • During summer you need bright indirect light whereas in winter you can go for direct light.
  • Fertilize monthly using a diluted liquid fertilizer or a pellet once every three months.
  • This plant needs soil that is both sandy and loamy. 
  • The soil must have good drainage as well as adequate organic nutrients.

Trust us when we say that scarlet Begonia produces one of the most glorious blooms ever. If you are regular with its care needs, you will get to see these blooms year after year.

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