Begonia Maculata – Care Tips, Common Problems

Begonia maculata is a showy indoor plant that is quite spectacular and popular with houseplant lovers. It’s not that difficult to grow if you understand its particular needs and how to solve or avoid any problems that you might encounter.

Quickstart Guide For Growing Begonia Maculata

  1. This plant likes to grow in bright, indirect light so a south-facing or east-facing window is best. The bright light will encourage strong growth and flowers to form. However, don’t expose the plant to direct sunlight as this will burn the leaves.
  2. It needs a premium potting mix that is also free-draining with a pH range from 6.0 to 7.0.
  3. It’s important to let the top inch of soil dry out in between watering and not to let the plant sit in water.
  4. This plant likes to be kept relatively warm at temperatures of around 65 to 86 degrees Fahrenheit (18 to 30 degrees Celsius).
  5. Providing your Begonia maculata with a high level of humidity is also important. The ideal place to put your plant would be in the bathroom or the kitchen as long as there is plenty of indirect light.
  6. Liquid fertilizer should be applied every two to four weeks during the plant’s active growth period.
  7. Regular pruning is necessary to maintain compact growth.
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About Begonia Maculata

Begonia maculata is a stunning plant that has olive green leaves with silver polka dots all over. If you didn’t know better, you’d think these were painted on. To add to the visual appeal, the undersides of the leaves are crimson in color.

When this plant flowers, it produces sprays of bell-shaped flowers that are white or pink with bright yellow centers. The flowers usually appear in spring through to fall.

Common names for this spectacular plant include spotted Begonia, polka dot Begonia, or trout Begonia.

Begonia maculata is a tropical plant that grows naturally in the tropical forests in Brazil. This is why it makes such a good houseplant in other parts of the world. Knowing where a plant comes from helps us to determine what its particular needs are. This makes it easy to give the plant the right conditions so that it can thrive and grow.

You’ll notice that the plant has thick stems. These can actually hold some water which is why overwatering can be a problem for this plant. It needs to be treated similarly to many of the succulents that we grow indoors when it comes to water requirements.

What Soil Is Best For Begonia Maculata?

Begonia maculata needs free-draining soil that can hold a little moisture. It should be slightly on the acidic side with a pH range of around 6.0 to 7.0. You can use a commercial potting mix, but you might like to make some amendments to it to help it drain more effectively.

Consider adding some perlite, wood chips, and a little compost. Both the perlite and the wood chips will help with drainage, and the compost will feed your plant.

To do this, all you need is a large tub or even a plastic garbage bin. Just tip in the bag of potting mix, add a few handfuls of perlite, a small amount of wood chips, and a handful of compost. Mix really well until you have a light and fluffy mix.

If you don’t use all the mix that you’ve created, store the remainder in an airtight container to keep moisture and bugs out.

Light Requirements For Begonia Maculata

Begonia likes plenty of indirect light, especially in the morning. Therefore, you should consider keeping your plant near an east or south-facing window. When your plant is getting just the right amount of light, the leaves will show their vibrant colors.

On the other hand, if your plant is not getting enough light, the leaves will lose some of their vibrancy and may even turn yellow and start to fall off the plant.

Conversely, if your plant is exposed to direct sunlight, the leaves can burn, and the spots will fade. You might need to experiment a little to give your plant just the right amount of light to allow it to thrive.

Just remember that this plant will not do well in a dark corner. It needs to be placed in front of a window to ensure that it gets enough light every day.

Krzysztof Ziarnek, KenraizCC BY-SA 4.0, via Wikimedia Commons

Temperature Requirements For Begonia Maculata

This plant prefers a nice, warm environment. The ideal temperature range is between 65 to 86 degrees Fahrenheit (18 to 30 degrees Celsius). Warmer temperatures are fine as long as you have enough humidity.

Humidity Requirements For Begonia Maculata

Being a tropical plant, Begonia maculata requires plenty of humidity to thrive. To get the best from your Begonia, you need to provide a minimum of 45% humidity but even higher is better.

Your plant will not die in an environment with low humidity but it won’t thrive either or look as lush as it could. One of the best places to keep your plant is in the bathroom. The daily steam from the shower will provide your plant with plenty of moisture for it to grow its best.

The kitchen is another good place to keep your plant because the steam from your cooking will also keep the air nice and moist.

There are also other ways that you can help raise the humidity in your home or even just around your tropical plants. Here are a few tips that you might like to try:

  • Group all your tropical plants together and place bowls or trays of water around them. Remember, you don’t want to have your plant sitting in water.
  • Another thing you can do is grab a flat tray and fill it with colorful pebbles and stones. Add some water so the level is about half way up the level of the stones. Then, you can place your plant on top of the pebbles without fear of the roots sitting in water. Remember to keep checking the level of the water and topping it up when necessary.
  • Invest in a humidifier that will increase the humidity inside your home.

If you grow a number of tropical plants, it’s a good idea to invest in a hygrometer. These are fairly inexpensive but will constantly test the air and tell you the humidity content.

Because these plants are prone to attacks of powder mildew, it’s not recommended that you mist the plant and get the leaves wet.

What Size Pot Should You Grow Your Begonia Maculata In?

Maculatas like to be a little root-bound. Therefore, select a pot that is not much larger than the root ball of the plant. It’s best to choose a fairly heavy pot like one made from terracotta or ceramic. This is because the plant can get quite top-heavy with all the growth.

Because the roots will be tightly packed into the mix in the pot, it’s necessary to repot your plant once a year or even just refresh the soil if you’re going to be using the same pot. It’s not necessary to go up a pot size when you’re repotting if you don’t want to.

To refresh the mix, just remove the plant from the pot and gently tease the soil out from around the edges of the root ball. Then, fill in the spaces with some lovely fresh mix and pop your plant back into the pot. Always water well after repotting but remember to let the excess drain away completely.

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Water Requirements For Begonia Maculata

Polka dot Begonias like to have moist soil but not too wet. In fact, your plant will do better if you let the top inch of soil dry out before you add more water. If you follow this rule, your plant won’t develop root rot which is something that can commonly kill these plants.

On the other hand, you should never let the soil dry out completely either, as this will cause the plant to drop its leaves. There’s a delicate balance between giving your plant just the right amount of water as opposed to too much or too little.

If you notice brown tips on your leaves, then you may not be giving it enough water. On the other hand, if the leaves are turning yellow, then you may be watering too much.

Another thing to remember is that these Begonias don’t like getting their leaves wet. Therefore, it’s important to only water the soil. You can check the moisture level in the soil by pushing your finger into the top inch. If it feels dry, it’s time to water but if it feels moist, wait another day and then test again. Alternatively, you could invest in a moisture meter that will tell you exactly how much moisture is in the soil.

Most importantly, don’t let your plant sit in water, as this will definitely promote the growth of root rot. Once you’ve given your plant a good drink, take the saucer or tray from beneath the pot and tip out any excess water.

Fertilizer Requirements For Begonia Maculata

This plant only requires a moderate amount of feeding. It’s best to use a well-balanced fertilizer that contains equal parts of nitrogen, phosphorus, and potassium. This is shown as a series of three numbers on the package and represents an N:P:K breakdown.

So, a fertilizer that has 10:10:10 on the package contains:

  • 10 parts nitrogen
  • 10 parts phosphorus
  • 10 parts potassium, in that order.

For Begonia maculata, it’s best to use a liquid fertilizer that you dilute with water. Use it at half strength for this plant. So, if the pack suggests mixing 0.67 fluid ounces (20ml) in 2.4 gallons (9 liters) of water, only make use of 0.33 fluid ounces (10ml) in 2.4 gallons (9 liters) of water.

In the growing season, apply this every two to four weeks when your plant needs to be watered. There’s no need to fertilize your plant in the winter as this is usually its dormant period.

If you don’t want to mess with mixing up a liquid fertilizer, you can use slow-release granules instead. Just sprinkle these on the top of potting mix and water. The granules will release the nutrients when the plant needs them.

If using a slow-release fertilizer, you should only have to top it up once every six months.

Pruning Your Begonia Maculata

To give your plant a nice shape and keep it bushy, you need to prune it regularly. Otherwise, your plant will become too leggy as the stems (commonly called canes) continue to grow upward.

The best way to create a bushier plant is by tip pruning. This involves removing the growing tip at the top of each stem. When you do this, it will encourage the plant to send up new canes from the base.

Make the cut to just above a node on the stem. A node is a small bump or bulge in the stem, and it’s usually where new growth comes from. It’s also the spot where the leaf meets the stem.

While you’re pruning, also remove any brown leaves or those that are diseased or dying and give your plant a general tidy-up. If your plant has any old woody stems that don’t have too many leaves on them, you can cut them back to the soil level.

It’s also important to provide your maculata with some support as the canes can easily topple over. Use thin wooden stakes or other decorative supports and loosely tie the stems of the plant to these. You might need more than one stake per pot if your plant is rather large.

How To Propagate New Plants

Begonia maculata is super easy to propagate just by using stem cuttings. These cuttings will root readily in either water or potting mix.

Take firm tip cuttings just below a leaf node. Remove the bottom leaves, leaving a longish piece of stem and one or two leaves at the top.

To propagate in water, simply use a small glass or jar filled with water and put your cutting into it. Place this on a windowsill, making sure that the cutting only receives indirect light. Change the water every couple of days, and soon you should see some roots start to form at the base of the stem. Your newly propagated plant can now be potted up as usual with some potting mix.

To propagate in soil, use a small pot filled with your amended potting mix. To help your plant along, you can dip the cut end of the stem into some rooting hormone. If you don’t have any rooting hormone at home, it’s been reported that dipping the stem into flour also works well.

Before pushing the stem into the soil, make a hole using a pencil or dibbler. This avoids rubbing off the hormone or flour while you’re planting. Firm the soil around the cutting and water well.

To create the perfect environment for your cuttings to produce healthy roots, make your own mini greenhouse by placing a plastic bag over the top of the pot. Make sure the plastic isn’t touching the plant, though. Alternatively, you can use an empty soda bottle by cutting off the bottom and putting it on the pot like a cloche.

Every second day you want to open the cloche and mist your cutting lightly with a spray bottle filled with water. This provides the ideal humid environment for the plant to produce roots. It’s just a scaled-down version of what professional propagators use when they’re mass propagating many plants on a daily basis.

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Is Begonia Maculata An Annual Or A Perennial?

Begonia maculata is a perennial plant. It actually produces canes, much like raspberries. These grow from the base of the plant and produce leaves and pretty little flowers in summer.

The leaves grow from nodes along each cane (stem), and the flowers are normally produced at the top of the stems. After some time, the canes will become old and woody without a lot of leaves on them. At this stage, they can be cut back to soil level and the plant will produce new ones.

Common Problems With Begonia Maculata And How To Fix Them

Keeping your plant healthy is important if you want nice strong growth. Regular pruning and maintenance should help to avoid any problems. Because your plant is living indoors, the large leaves are prone to collect dust and other dirt particles from the air.

You can keep the leaves nice and clean by wiping them over with a damp cloth at least once a month. Support the leaf with your hand when you wipe it to avoid damaging it.

However, because maculatas prefer a humid environment, you might come across some fungal issues. That’s because fungal diseases thrive in warm, humid conditions. Here are some problems to look out for:

  • Powdery mildew. This shows as white powdery spots on the leaves and can be difficult to control. The best thing to do is remove the affected leaves and spray your plant with a fungicide. It’s also been found that a solution of milk and water is quite successful in treating this disease. However, you have to keep up the spraying until there’s no more signs of the disease recurring.
  • Botrytis. This disease thrives in moist conditions. It appears as soggy, brown spots on the lower leaves. Especially those leaves that may be touching the soil. To treat this, remove the affected leaves and apply a fungicide to the plant.
  • Bacterial leaf spot. This results in small brown spots on the leaves. To treat, remove the affected foliage and spray with a fungicide.
  • Stem rot and root rot. These diseases cannot be successfully treated so prevention is best. Make sure you only water the plant when the top of the soil is dry and never let it sit in water.
  • Whiteflies and mealybugs. These are common houseplant pests that eat the sap from the leaves. To treat these, you can spray the plant with an insecticidal soap or by using a mixture of neem oil and water.

Most fungal diseases can be avoided if you have good air circulation around your plants. If they’re next to a window (and they should be), just open the window to let some fresh air in. You could also turn on the ceiling fan if you have one to increase the air circulation.

Alternatively, you can just use a portable fan placed near your plants to increase the airflow. Just don’t direct the air from the fan directly onto your plants, as this will dry them out.

Frequently Asked Questions

Is Begonia maculata toxic?

Like many other indoor plants, maculatas are toxic to pets like cats and dogs. It’s best to keep your pets and children away from these plants.

What causes the leaves to turn yellow?

This is normally a sign of overwatering. However, less-than-ideal conditions can also contribute to the yellowing of the leaves. These could be things like not enough light, drafts, not enough fertilizing, or an attack of pests or diseases.

Why causes the leaves to drop off the plant?

This could be caused by a lack of humidity. It may also be caused by not providing your plant with some new potting mix as the old mix has become stale. Try to increase the humidity around your plant and repot to refresh the soil if you haven’t done so in a while.

Why are there brown tips on the leaves?

This is most likely due to the plant not receiving enough water. If you’ve let the soil dry out completely, give the plant a thorough soaking and then let the excess water drain away.

Should you mist Begonia maculata to increase humidity?

Misting your maculata is not recommended as wet leaves encourage fungal disease growth such as powdery mildew.

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