Rex begonia: Diseases and Remedies (Explained for Everyone)

NOTE: Rex begonia may be referred to as Begonia rex-cultorum in this article, in fact, those are the same plants, Begonia rex-cultorum is the botanical name for Rex begonia.

Begonia rex is one of the most beautiful and dramatic begonias. Sometimes called painted-leaf begonias or fancy-leaf begonias, these plants are known for their variegated leaves. They have large leaves that are brightly colored in various shades of green, red, silver, and even purple.

Many growers pinch off blooms to maintain breathtaking leaf displays because these plants are grown almost exclusively for their foliage. If you want to plant outdoors, plant in May after the frosts. The plants may grow to less than 12 inches in a year, because they have a moderate growth rate. The rex begonia is poisonous to animals.

Why does my Begonia rex-cultorum roots have rot?

Root rot on your Rex begonia (Begonia rex-cultorum) can be dangerous if left untreated. In order to keep your plant alive, we strongly suggest that you follow our advice if the signs start to show: blackened and mushy roots.
Rex

Why does my Rex begonia have gray mold spots?

Gray mold spots are a specific fungus that regularly harms flowers and spreads swiftly. If you notice any brown (or gray) spots, this fungus is probably to cause. You risk your plant dying if you ignore these warning indications.

Our Solution

The answer is obvious once you recognize the cause of the problem. Most frequently, it results from the Begonia rex-cultorum being overwatered. We strongly advise you to remove the damaged plant parts, cut off the diseased roots and leaves, and then repot your plant in a new container with sterile potting soil.

Why does my Rex begonia have leaf spots?

Leaf This type of disease is one of the most frustrating for Rex begonia owners, we give you all the leads to spot and save your plants that present symptoms such as leaves that suddenly change color, or wilt/droop.

Why are my Rex begonia leaves turning yellow?

In the world of horticulture, yellowing leaves are undoubtedly the most common problem. The two main causes of this problem are overwatering and a lack of nutrition.

Whether you think your plants are getting too much water, cut back on how often you water them, and take the following measures to see if they might be nutritionally deficient:

Each deficiency produces a different yellowing on the Begonia rex-cultorum in question, here’s how to spot them:

  • Magnesium deficiency starts as yellow patches between leaf veins on older leaves. Veins stay green as yellow moves from the leaf center out. Leaf edges turn yellow last.
  • Yellowing between leaf veins is another sign of iron shortage, but young leaves on plant tops and branch tips are initially affected.
  • Sulfur deficiency starts with the newest leaves, turning them yellow throughout.
  • Potassium deficiency shows itself when leaf edges turn bright yellow, but the inner leaf stays green. Older leaves show symptoms first, and leaf edges soon turn brown.
  • A lack of nitrogen is indicated by a widespread yellowing. Older, inner leaves are the first to yellow. As the yellowing progresses, it eventually touches young leaves as well.

Our Solution

You only need to act in accordance with the symptoms listed above. You can address a potassium or nitrogen deficiency by buying a particular soil, and a gardening store consultant will be able to advise you on how to do that. Furthermore, you can also limit how frequently you water your plants.

Is my Rex begonia sunburned?

You can easily tell if your Rex begonia (your Begonia rex-cultorum) has a sunburn. In this case, your plant will change color, starting to turn yellow or white, much like it does on us.

Sunburned

The leaves of your Rex begonia can also change color in case it gets too much water or not enough light, as we saw above.

The bottom of the yellow leaves with a shaded area closer to the base can be examined to determine if they have been sunburned. If this part remains greener, the yellow leaf is most likely sunburned and not something else.

Why are my Rex begonia leaves turning brown?

Most of the time, leaves of a Rex begonia that turn brown is a sign that your plant has been sunburned, it has probably been exposed to too much direct sunlight. Don’t panic, your plant probably won’t die from this, but its growth will take a hit.

Should I leave my Begonia rex-cultorum in direct sunlight?

No! Don’t leave your Begonia rex-cultorum (or Rex begonia) in the sun if it displays the symptoms mentioned above; that’s why it’s in such a bad situation.

Our Solution

As stated in the paragraph above, the cure is straightforward: simply position your plant’s Rex begonia so that it is out of direct sunlight. With proper watering and this method, your plant should quickly come back to life.

Why are my Begonia rex-cultorum leaves drooping or wilting ?

When you become dehydrated, this usually happens. Large plants are more vulnerable since they need more water on a regular basis than smaller plants.

Drooping

Whether your Begonia rex-cultorum plant’s pot appears light, the soil and roots are likely fairly dry and need water, so you can readily tell if it needs to be hydrated.

Our Solution

If the soil in your plant’s pot is completely dry, you will need to start by moistening it so that the roots will also benefit from the water. A common mistake is to drown the Rex begonia right after a dry period thinking that it needs a lot of water.

This is the case, but giving too much water at once is the best way to finish it off, you should actually water the soil normally, resuming a quiet watering rhythm.

Caring Tips for Begonia rex-cultorum

Water Occasionally

Water is necessary for your plant to live, but timing and amount of watering must be balanced. Overwatering could have disastrous effects on your own name, as we already mentioned.

The best way to know if your plant needs water or not is to touch the soil, if you feel it is still wet, it is probably a good idea to wait a few more days.

Always keep temperatures stable

Maintaining a consistent temperature for your Begonia rex-cultorum is also a good idea, especially if it is kept indoors. At GreenShack, we typically advise reserving a temperature between 65 and 85 degrees F. Of course, avoid positioning your Begonia rex-cultorum close to air conditioners, radiators, or other sources of hot or cold air.

Keep your Rex begonia Dust-Free

This one concerns indoor plants, just like on your furniture, dust is also deposited on the leaves of your indoor plants, the problem is that it can prevent them from receiving the necessary light, this would slow down (or even stop) the photosynthesis process, and eventually, they would lose their colors.

This would be a true journey into hell for your Rex begonia and would also satisfy the pests.

To remove the dust from the leaves of your plant, take a microfiber cloth and gently rub the leaves. You can wet the cloth to make it easier to remove the dust, but never use corrosive products (such as rubbing alcohol!)

Keep drainage in mind

If you tend to overwater, you need to pay attention to your drainage, and we advise choosing a saucer and a pot with drainage holes if they are not already there.

You can add volcanic rocks (or any other pebbles with holes) to the bottom of your pot in the interim if your pots don’t already have holes in them. This will help to form a channel so that the water doesn’t pool there for too long (preventing the rot of the roots!).