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Begonia Masoniana (Iron Cross Begonia) #1 Best Care Hacks

Begonia Masoniana (Iron Cross Begonia) #1 Best Care Hacks

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Begonia Masoniana is a classic specimen for collectors of exotic foliage plants. It has medium sized, asymmetrical leaves with a puckered, leather-like texture and a bristly feel to them.

The distinction is the chocolate brown, cross-shaped markings in the middle of apple green leaves. The markings resemble the Iron Cross symbol used during medieval crusades, from where the plant gets its popular name, Iron Cross Begonia. Simply awe-inspiring.

Iron Cross Begonia is perennial, rhizomatous plant characterized by palm-sized, colourful leaves arising from thick rhizomes (fleshy stems that resemble roots) that grow along the soil surface. As per the American Begonia Society, the plant has eastern origins being native to India or China.

Masoniana has pinkish white flowers but they pale out in the face of the foliage. A great way to grow Begonia Masoniana is by a window sill. It may be small but it has oomph, with a stunning aesthetic quality that can pull a room together with its presence.

Begonia Masoniana care broadly involves cool temperatures, moist soil, boggy air and bright light. Let’s go through these in detail.


How not to Kill your Begonia Masoniana




The ideal soil condition for Begonia Masoniana care is a porous, slightly acidic planting mix. If you choose to grow Begonia Masoniana indoor, I’d recommend going for a soilless substrate containing peat moss and perlite or vermiculite.

Leave out compost, garden soil etc. unless you want to grow Begonia Masoniana straight in the ground. Garden soil often gets quite wet and compost may induce diseases particularly in the warm environs indoors.

A good soil mix that you can use to grow Begonia masoniana straight in the ground, is half part soil, and the other half, a mix peat moss, leaf mulch or humus thrown together along with sand. Pine bark, wood shavings or any other organic substance that can add to soil looseness and is easily available to you, makes it into the mix.

Grown in such a loose soil mix, the rhizomes spread nicely and provide surreal patches of ground cover.

In order to grow Begonia masoniana the soil should ideally be mildly acidic to neutral, with a pH range of 5.5 to 6.5. All your mulch, peat, bark etc. improves acidity but the levels change over time, so don’t fuss over it too much.

One Begonia Masoniana care hack is to use African Violet potting mix which has the right nutrient mix for these plants.


Do coffee grounds help in Begonia masoniana care?

There’s a popular idea making the rounds these days that coffee grounds help improve soil acidity and suppress soil diseases. Well, this is a largely debatable idea yet to be tested scientifically.

Prof. Linda Chalker-Scott of WSU, based on her research advises that a small amount of coffee grounds on the top of the soil may indeed have some benefits which you can read about here.

In any case I’ve been throwing coffee grounds from my kitchen into my compost mix and they have indeed proven to be beneficial for airing the soil and improving moisture retention, both useful properties for Begonia masoniana care. So you have my vote on coffee grounds, one way or the other.



You can grow Begonia masoniana under adequate light but without strong direct sun. For outdoor growing, a shade structure or under a tree is good. Indoors, by a windowsill without extended sun exposure would be great.

A little direct sun (such as an east window) is great particularly in the winter months.

Begonia masoniana care requires several hours of the described lighting conditions throughout the growing season i.e. spring-autumn to encourage lush growth, well-defined cross markings and good flowering.

You can also get great results using artificial growlights, particularly if you live in the northern zones. A consistent 10-12 hour exposure works well for Begonia masoniana care. Make sure you place your plant a few inches away from the growlights.



The rhizomes are a great help when it comes to Begonia masoniana care. They store water and nutrients, making it possible for the plant to survive irregular watering and temperature variation.

That said, if you want a healthy plant you must give it an evenly moist environment. No plant enjoys neglect. As long as the potting mix is course and the planter drains excellently well, you can water regularly during summer but never overwater.

Try to store rainwater if grow Begonia masoniana. Rainwater is mildly acidic in nature which also beneficial for these plants.

Water the plant when the top soil visibly dries out. Intermittent dryness is good for the plant. The peat, mulch, compost, etc. used in the soil have very good water retention properties and help in moisture management.

One Begonia masoniana care hack is to use lukewarm water during winters and very sparingly. The plant doesn’t grow in winter but it’ll survive.

These plants are susceptible to fungal problems. Grow Begonia masoniana away from sprinklers and sprays. Water only at the roots.



Iron Cross Begonias are cool temperature plants. They thrive in temperatures of 15°C to 30°C (60°F – 85°F). They can take a slight chill for a short period, but they are not frost tolerant, so the leaves perish at temperatures below 55°.

According to University of Florida, temperatures below freezing can damage or kill leaves, but these plants usually produce new leaves from the rhizomes once warmer temperatures return in spring.

Gardeners can grow Begonia masoniana as herbaceous perennials that revive from the rhizomes every spring, providing ground cover in the shade garden.



Although they like humidity, in my experience you don’t need to go nuts over this aspect when it comes to Begonia masoniana care. These plants belong to climes with moderate to high humidity but they thrive in levels of around 50%.

If you grow Begonia masoniana indoors in a dry aircon environment, they seem to adapt to this fairly well although they do like it boggy around them.

Feel free to use a humidifier, but misting the plant is a bad idea. They are super susceptible to mildew.

An oft-quoted Begonia masoniana care hack is to stand the pots on pebbles trays to improve humidity. I am personally not a fan of this method due to the danger of soil getting soggy through the drainage holes.



Include fertilization in your Begonia masoniana care routine because this plant responds well to feeding, particularly the mature ones.

You can use a rich organic manure right at the beginning, in the soil mix used to grow Begonia masoniana.

Subsequently, a balanced” fertilizer like a 10-10-10 or 20-20-20 can be applied. Stop feeding in winters when the plant is in dormancy.

I’d recommend a good liquid chemical fertilizer suitable for foliage plants administered once to twice a month diluted to half its prescribed concentration. This is just a precaution I recommend when it comes to the use of chemicals.



There are two main ways to propagate a Begonia masoniana – root division and leaf cutting. For the best results, you’ll want to use the root division process, because it’s almost fail-safe.

But you can also propagate Begonia masoniana through leaf cuttings, which is honestly a natural wonder to behold.

We’ll walk you through both methods step-by-step down below.



Iron Cross Begonias are perennial, rhizomatous plants that grow to about 15″ to 18” tall with max 6″ leaves. The growth habit is largely horizontal.

You can choose how you’d like to grow Begonia masoniana because they are quite versatile – hanging baskets, cute ceramic table top pots, terracotta planters for the patio or your in your shade garden as ground cover.

Begonia masoniana rhizomes are thickened, fleshy stems that spread horizontally at the soil surface. A juvenile plant in a small pot often grows out of the edge of the pot quite quickly.

Once you grow Begonia masoniana to a decent size I would recommend shifting it to a hanging basket. Not only is it easy to drain, the growth is quite gorgeous, after the rhizomes grow over the edge and the Iron Cross leaves envelop the sides.

For a well-rounded growth keep rotating your pot, so that the sun reaches all sides of the plant.

I currently have them in a hanging basket but I am waiting to grow Begonia masoniana in the ground to make a nice perennial patch.

With age the oldest part of the rhizome will stop producing leaves and eventually die.



For Begonia masoniana care, use a shallow wide pot, preferably clay or terracotta. A bonsai pot works nicely.

Pruning usually consists thinning down an overcrowded pot to prevent mildew problems from a lack of ventilation. In my opinion, unless you find the plant unattractive, you needn’t prune. Pruning yields cuttings which can be propagated.

Once you see the roots of the plant coming through the pot’s drainage holes, it’s time to re-pot it.



You can propagate Begonia masoniana using cuttings taken from any part of the plant – stem, leaf, part of a leaf, root, rhizome.

If you’re looking propagate in order to overwinter the young plants, choose late summer to early autumn. Otherwise early spring is always a perfect choice.


Propagate Begonia masoniana with rhizome cuttings

Rhizome is the thick stems of the plant running along the soil surface often confused for the plant’s roots.

  • You case use rhizome tip cuttings or 2 – 3 inch stem cuttings
  • Make sure they have a couple of leaves and let them callous for a few hours
  • In a small pot place a layer of gravel followed by a coarse mix of perlite and peat about 4 inches thick.
  • Place the rhizomes horizontally on the surface slightly pressing them under the soil leaving the top exposed (not burying them).
  • Keep the pot in bright shade or under a growlight
  • Keep the soil just about moist but not wet and maintain 70°-75°F (21 – 24°C)
  • Don’t disturb the cutting until established. Keep out of strong breeze.
  • They should take root in 2 to 3 weeks.
  • Pro-tip 1: Make several cuttings in separate pots and group them together to improve chances of success


Propagating Begonia masoniana with leaf cuttings

The most fun technique to propagate Iron Cross Begonia is with leaf cuttings struck in a mixture of moist peat moss and perlite.

  • Cut a few mature leaves with about an inch of the petiole (stalk).
  • Take potting mix with 50/50 sterile peat and perlite evenly moistened, in a germination tray.
  • Make slightly angled holes and insert the petioles such that the leaf is flat on moist the soil surface.
  • Insert hairpins through the leaf into the soil so that the leaf veins are firmly in contact with the soil. Like coasters on a table, geddit?
  • Place the tray in 70°-75°F (21 – 24°C) under a growlight, misting the soil occasionally.
  • You should have new plantlets all over the leaf in about eight weeks.
  • Let them grow to about 3 inches before transplanting.



Begonia masoniana or Iron Cross Begonia are fairly low maintenance as far as pests are concerned mainly because of the gristly, hairy surface.

There are however a few problems that you must be mindful of as part of your Begonia masoniana care guide.


Powdery white patches on the leaves

This is a clear sign of mildew, a fungus which causes these patches on leaves, stems and buds. There are a couple things you can do.

Curative: If it’s just one or two leaves, pinch them off and dispose them far away in a dry spot where they can’t grow or spread. Restrict watering to roots of the plant and only in the mornings so that excess water on the leaves will quickly evaporate. Improve air circulation around the plants. Severe cases will need fungicide treatment but honestly, don’t let it go that far.

Preventive: Spray a solution made of 1 tablespoon baking soda to one quart water and two drops of dishwashing soap.


Crippling of leaves or stem terminals

This usually happens due to spider mites. Look for webs at the midribs and nodes on the underside of leaves and at the terminals. Spider mites grow due to excessive dryness which makes the leaf surface suitable for these insects.

Curative: Pinch of the affected terminals and wash the whole plant with a water jet. You can do a miticide spray treatment at a frequency prescribed on the cover. But these are usually not effective in the long run.

Preventive: You need to manage a tricky balance between wetness and dryness when you grow Begonia masoniana. Mist the plant once or twice a month in the morning so that the moisture dries up during the day. Keep the surroundings weed free – you can use leaf much soil cover for this. Regular neem oil and insectidal soap treatment is also advisable.


Leaflet margins and tips drying

This could be the cause of direct sun exposure. You have to grow Begonia masoniana in bright shade. If you’re growing them outdoors make sure they are kept in dappled sunlight or better still, bright shade.


Sudden collapse

This could be caused due to root rot or stem rot often caused by a fungus called Pythium.

Curative: If your plant is mature with several stems you may be able to save your plant by salvaging the heathy roots and stems. Completely cut out the rotted portion of the root and repot your plant. Simultaneously propagate Begonia masoniana using the tip/stem rhizome cutting method.

Preventive: Never overwater this plant and always let the soil dry out partially between waterings. During winters drastically reduce watering.



The single most important aspect of Begonia masoniana care is ensuring the right amount of water because root and crown rot is the most common reason for death. Here are a few handy tips to keep Begonia masoniana problem-free:

  • Water only when the soil dries out 20-40%.
  • Water only at the roots.
  • Only dappled light or bright shade. No direct sun.
  • These are pretty compact growers. So don’t pruning the stems but deadhead the flowers.
  • They are susceptible rot due to excessive salts. Water deeply using RO water if your regular water is heavy on mineral salts.
  • This plant look good in hanging pots
  • Terracotta pots dry out the moisture from the bottom. Placing bits of terracotta fragments at the base of the planter helps too.
  • Use shallow planters to limit water to the roots
  • Limit winter Begonia masoniana care to just minimum watering and absolutely no fertilizers. Apply organic insectidal soaps to avoid spider mites from dryness. Use lukewarm water during winters.
  • The leaves can’t withstand frost. So keep them indoors during winters.
  • A best practice to follow with regards to Begonia masoniana care is to keep propagating during the growing season. This is you best hedge against any losses.




How long can you grow Begonia masoniana?

No begonia grows for ever. The main rhizome dies after few years. If you follow proper Begonia masoniana care guidelines they will live up to 5 years. It is recommended to propagate Begonia masoniana every year.

Should I mist my Iron Cross Begonia?

Avoid misting. This is strange advice considering the tropical rainforest origins of this plant. But misting causes more problems than help grow Begonia masoniana. We have given you other humidity management methods in the section above which you can go through.


Do coffee grounds help in Begonia masoniana care?

This is known to have some advantages for improving soil properties. Please read the section on ideal soil for Begonia masoniana to learn about coffee grounds. I recommend their use only if the plant is grown outdoors like ground cover.

What’s the best method to propagate Begonia masoniana?

My vote goes for rhizome tip cuttings in soil given the success rate. But, do try out the leaf cutting method. If you succeed, the joy is insurmountable.


Begonia masoniana or the Iron Cross Begonia is one of those cute compact growing plant that everyone likes to own. But this is a plant best left to the more experienced growers. Personally I’ve found Begonia masoniana care a little tricky particularly when it comes to watering and humidity.

If you’re new to begonias then it may be a good idea to start off with some easy growing varieties such as Begonia Pavonina or Begonia Maculata.

Finally, if you’re here reading about Begonia masoniana care I take it that you’re no first time parent and have a penchant for exotics. I suggest try growing some exotics ferns along with this plants. That’s what I’ve done and the results are spectacular to behold.

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