The stunning, spotted foliage of the polka dot begonia makes this houseplant popular among beginners and more seasoned indoor gardeners alike. This article will be your ultimate guide to caring for a healthy polka dot begonia.
Here’s how to care for a polka dot begonia:
- Maintain moist soil
- Provide bright, indirect light
- Use well-draining potting soil
- Choose semi-porous pot like glazed clay
- Set temps to 65-85°F and 45% humidity
- Fertilize monthly during active growing season
Keep reading for lots more great care tips as well as information on polka dot begonia pests and common care issues. Soon, you’ll have a beautiful polka dot begonia as part of your indoor garden!
Polka Dot Begonia Overview
At first glance, the polka dot begonia doesn’t even look real, but those pretty white dots are simply this houseplant’s variegation.
Let’s rewind for a moment. The polka dot begonia or Begonia maculata is appropriately named considering that “maculata” means spotted.
This begonia comes from southeast Brazil and grows in some Brazilian states, including Rio de Janeiro and Espírito Santo. Instances of the polka dot begonia have also been reported in the rainforests of the Atlantic.
The leaves of the polka dot begonia are long and square-ish. The color of the leaves is green, but it’s the white or silver polka dots on the exterior surface of the leaves that really draws everyone’s attention.
Underneath, the leaves have some purple/red coloration.
Besides its undeniable beauty, another reason that the polka dot begonia is so beloved is that it’s very manageable for indoor growth. Reaching heights of no more than two feet, you can grow one of these houseplants in a cubicle or a small apartment without being overwhelmed with greenery.
If your polka dot begonia is especially happy, it might grow flowers. These develop in clusters and are often pink or white.
Should your begonia decide to bloom, it will happen in the spring until summer ends. The undersides of the leaves might turn redder when blooming, which just makes the polka dot begonia that much more beautiful.
The polka dot begonia is not toxic to pets, but you still don’t want your cat or dog getting near its leaves. For one, they’ll ruin the plant in their inquisitive munching. Also, your pet could have diarrhea and/or vomiting for their troubles!
Caring for Polka Dot Begonia
You’ve just brought home a gorgeous young polka dot begonia and you don’t want to screw up even one facet of its care. Then you’ve come to the right place! Per the information in the intro, here’s the full rundown on how to care for a polka dot begonia.
Watering a Polka Dot Begonia
Watering the polka dot begonia will require careful consideration. The plant needs moist soil, but if the soil is too moist, then your plant is in trouble.
Begonias do not tolerate standing water, as it accelerates the development of root rot. As the plant’s roots die, it’s not too long before your once-lovely polka dot begonia is brown and wilted, then dead.
You have two defenses against overwatering your begonia as well as other houseplants. For one, get a pot with adequate drainage holes. I’ll talk more about the polka dot begonia’s ideal pot later, but drainage holes are a must.
Second, don’t water on a schedule. I know it’s tempting to water your begonia every Sunday, but that’s a recipe for root rot.
Rather, use the fingertip test. When the soil is dry maybe half an inch down, then it’s time to water your begonia.
Some indoor gardeners let half its soil dry out, others even more than half. If you’re a more experienced gardener, then sure, you can do this. For beginners though, waiting this long means your plant is probably dehydrated. I don’t recommend it.
If you ramp up your watering habits in the warmer months, don’t panic. Like you need to stay hydrated more frequently in the summer, so too does the polka dot begonia.
This begonia doesn’t exactly go inactive during the winter, so you’ll still have to water it. It will be far more infrequent though.
Polka Dot Begonia Light Requirements
Bright, indirect light is the best type of lighting for the polka dot begonia.
Remember how earlier I said this begonia is variegated? That refers to its leaf patterning and coloring, which the polka dot begonia has in spades.
Variegated houseplants have very specific lighting requirements. Too much light will burn them, which admittedly is not all that different from many other houseplants.
Too little light can cause their variegation to fade. That being said, the polka dot begonia is moderately low-light tolerant. Still, I wouldn’t push your luck and keep this begonia in the dark for very long.
The light that comes through a curtained window will make this plant happiest. You’ll also see the greatest depth of polka dot color and size when your plant gets the right lighting.
Even more so, you increase the chances that your begonia might flower.
Easterly-facing windows are a good pick for the polka dot begonia. These windows receive light as soon as the sun is up, prohibiting your begonia from being starved of light for too long.
Northerly-facing windows are another great choice, especially for plants that can’t tolerate bright sunlight such as the begonia. These windows, while sunny, never receive direct light.
Best Soil for a Polka Dot Begonia
The polka dot begonia must have well-draining soil to prevent standing water.
You don’t need to go out of your way to procure soil for your begonia. Standard potting soil works just fine for this particular begonia.
I recommend adding soil amendments for aeration. After all, the longer the soil is in the pot, the more compacted it will get. That can prevent air from traveling throughout the soil, and water too, creating pockets of standing water.
Vermiculite, a type of hydrous phyllosilicate, shines appealingly. Much more so, this mined mineral aides the soil in draining water and staying airy.
A handful of sand will also improve drainage due to the size of the particles. Just don’t add too much sand, as then the soil gets dry and loamy, and those aren’t ideal conditions for the polka dot begonia.
The volcanic glass perlite helps soil resist compaction while improving drainage and maintaining a loose soil texture. It’s the perfect addition to your polka dot begonia’s pot!
Best Type of Pot for a Polka Dot Begonia
Knowing what you do now about the polka dot begonia’s dislike of standing water, you need a semi-porous pot that will keep water moving.
Terracotta or clay pots with a plastic liner are one such option. The clay materials are completely porous while the plastic liner is nonporous.
The inclusion of the liner will hold onto some moisture so you’re not watering your houseplant too frequently, thus upping the risk of overwatering.
Glazed terracotta or clay pots are another option. The layers of glaze reduce porosity so water still absorbs through the pot, but at a slower rate.
Terracotta and clay pots can be appealing and decorative, so please make sure yours has drainage holes. Yes, believe it or not, not all houseplant pots include drainage holes!
Handle your pot with care, as both materials are very breakable. The plastic pot liner won’t buckle though.
Polka Dot Begonia’s Ideal Temp and Humidity
The polka dot begonia’s perfect temperature range is between 65- and 85-degrees Fahrenheit. This is unsurprising considering its home in Brazil and some rainforests.
The good news is that this temp range is right within normal room temperature.
If you turn your air conditioner off on a warm spring day to save on your electric bill and the temps climb into the low 80s, that’s fine for this begonia.
Even mid-80s are a-okay but try not to go too much hotter. You could dehydrate your polka dot begonia, which will wilt and perhaps turn brown around its lovely, dotted leaves.
Carefully watch for low temperatures as well. You don’t want to turn off the heat on a cold day in late autumn and let your polka dot begonia fend for itself, as this plant will not do well.
The polka dot begonia is not cold-tolerant. If the temps drop down to 59 degrees or lower, your plant could die. Some can tolerate temperatures down to 40 degrees, but do you really want to take your chances?
Unlike many houseplants from tropical regions, the polka dot begonia doesn’t require high humidity. It likes its humidity at 45 percent.
This is within the average range of relative humidity in most households and offices, which is between 30 and 50 percent. Thus, you shouldn’t have to do anything special for this begonia’s humidity needs.
That said, listen to your plant. If you notice that the polka dot begonia has crispy leaves, drooping and wilting, and browned edges with yellowing, those are all signs your plant needs more moisture.
Don’t mist your polka dot begonia. Not only is this job very time-consuming, but the begonia is susceptible to powdery mildew, so it’s better to keep its leaves dry.
Instead, buy a humidifier.
Best Fertilizer for a Polka Dot Begonia
Fertilizing the polka dot begonia could also increase the chances of it blooming, so what do you use? I recommend water-soluble plant fertilizer.
As the season starts, you might use a formula with more nitrogen than phosphorus and potassium. Then, as the season gets underway, switch to a balanced mix of nutrients.
Start applying fertilizer during this plant’s active growing season in the spring. Every month, fertilize until the end of the summer.
Although the polka dot begonia doesn’t go dormant in the winter, it doesn’t need fertilizer then. That’s true of the autumn months as well.
Common Issues with Polka Dot Begonia
If you’re having a harder time than anticipated growing the polka dot begonia, you’re far from alone! Here are some common issues that afflict this plant and how to overcome them.
Don’t let pests ruin the wonderful progress you’ve made growing your polka dot begonia. Treat spider mites and aphids as soon as you see them so they don’t spread to other plants. Here’s what you need to know.
1. Spider Mites
Tiny, creepy, and hungry, spider mites don’t only like polka dot begonias, but houseplant species in the hundreds. That means, as I alluded to above, that a problem with your polka dot begonia and spider mites can easily spread to the rest of your indoor garden.
The color of spider mites runs the gamut, and these insects measure less than 0.04 inches, so detecting them is hard. The webs they lay can be an indicator.
Since they’re so small, many common household products can remove spider mites. Rubbing alcohol is one such solution and neem oil is another.
Whether you call them the blackfly, greenfly, or aphid, these small insects are a nuisance. Like spider mites, aphids come in a multitude of colors.
Aphids drink plant sap. When female aphids are born, some start pregnant to accelerate spreading an infestation.
You can flick off aphids by hand (or using an instrument like a chopstick), spray them with a gardening hose, use neem oil, or bring ladybugs to your indoor garden to kill them off.
Besides pest infestations, keep your eyes peeled for the following polka dot begonia diseases. Some of them are quick plant killers!
1. Southern Blight
The fungal disease known as southern blight can occur in more than 500 species of plants. The symptoms include leaf wilting and leaf discoloration, but this disease progresses fast. Eventually, the whole plant collapses and dies.
Fungicides might be able to treat southern blight in houseplants if you catch it early enough. Keep your affected begonia quarantined until it’s feeling better.
No, I don’t mean rust as in what happens to metal, but rust, the series of fungal plant diseases. You’ll know your polka dot begonia has rust because it will develop spots in colors like red, purple, yellow, brown, or orange.
These spots can become pustules if left untreated. When the pustules open, spores can spread. If the spores reach the rest of your indoor garden, they too develop rust.
To treat plant rust, prune the affected areas. In the future, don’t overwater your plants, as that’s a main cause of plant rust.
3. Leaf-Spot Disease
Leaf-spot disease can also leave your begonia spotted, but not in a good way. This viral, bacterial, or fungal condition occurs from injury to your plant.
The spots that develop are lesions that can eventually lead to cell death. To treat leaf-spot disease, prune the affected areas and apply a fungicide.
Other Begonia Issues
If you still can’t pinpoint what’s wrong with your polka dot begonia, then it could be due to one of these causes.
· Slowed growth: If you’re caring for your polka dot begonia by following the tips in this guide and it’s still not growing, then it could be that you haven’t cleaned the plant’s leaves well enough. This can prevent light absorption, which reduces the rate of photosynthesis.
· Brown leaf tips and yellow halos: The inclusion of yellow halos on your polka dot begonia’s brown leaves can leave you feeling spooked. This is a humidity issue, so please increase the plant’s moisture ASAP.
· Legginess: When the stems grow more than the rest of your polka dot begonia, it’s become leggy. Prune the extra growth and move the plant to a brighter area, as it needs more sunlight.