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Euphorbia japonica Care (Common problems And Solutions)

Euphorbia japonica is an interesting, highly sought-after dwarf cacti plant. It’s a succulent hybrid bred from two plants endemic to South Africa. The plant is quite atypical when it comes to looks- it has a pineapple/cactus-like caudex that grabs attention when grown indoors.

Euphorbia japonica thrives in well-drained soil and sufficiently lit environments. Provide the plant with plenty of light (at least 5-8 hours in a day), moderate moisture (40-50%), and keep an eye on pests such as whitefly and diseases such as stem/root rot. The temperature should be kept around 70-80°F (21-27°C) for the plant to flourish. Fertilizing is not a must for this plant, but it can be done to boost poor soil. This dwarf plant barely requires pruning or trimming

In this guide, you’ll learn all the crucial care and species profile details of the Euphorbia japonica. You can be assured that this is the information resource you need to start cultivating this fascinating plant like an expert.

What Does a Euphorbia japonica Look Like?

Euphorbia japonica, also known as a Pineapple Euphorbia or Cocklebur, is a lightly-leaved plant with a bulbous stem/root structure of the family Euphorbiaceae (the 4th largest family of flowering plants).

The parent plants of this hybrid dwarf hybrid are Euphorbia susannae and Euphorbia bupleurifolia, all native to South Africa.

As the top of the Cocklebur grows (note that it’s a slow-growing Euphorbia species), the caudex becomes a hardy basal stem structure.

The plant has turnip-like roots which get broader rather than elongate. The stem is quite rugged, with succulent, thorn-like structures. 

Remember that the stem and the roots co-join to form the bulbous structure, which is the primary identity for this plant. The leaves are narrow, willow-like, and light green.

This plant species produces small yellow-green flowers that create quite a charming look. Euphorbia japonica will primarily flower during spring and summer. If the plant is potted, it’s not always given that it’ll bloom each and every year.

Combining all the structural features, the general look of the plant is like that of pineapple or a palm tree.

The entire plant is usually spherical, growing up to a maximum size of 1ft (12 inches, 30 cm) long and 1.67ft (20 inches, 50 cm) in diameter. Depending on where the plant was bred, there may be variations in size, shape and color.

The plant is superbly hardy and will survive a vast range of conditions, making it an excellent choice for a household plant. However, it’s still good to maintain some standard conditions (as we’ll discuss below) to avoid stressing the plant.

Euphorbia japonica Care Details

OriginSouth Africa
Scientific NameEuphorbia x japonica
FamilyEuphorbiaceae
Common NamePineapple Euphorbia, Cocklebur
Plant TypeSucculent, bulbous, dwarf, small
Max Growth (approx)1ft, (12 inches, 30 cm) long and 1.67ft (20 inches, 50 cm) in diameter
Watering NeedsThe plant only needs the soil to be moist to thrive. Avoid underwatering and overwatering
Light RequirementsSufficient bright light, preferably indirect
Humidity40-50% Average humidity
SoilAny well-drained soil. Preferably a cacti/succulent mix
FertilizerWater-soluble, nutrient balanced fertilizer, diluted at half its strength
Planting SeasonEarly spring to late winter
Temperature70-80°F (21-27°C)
PestsSpider mites, whiteflies, mealybugs, and scales
DiseasesMildew, drooping, root/stem rot
PropagationCuttings
PruningThe dwarf plant barely requires pruning.
Re-pottingNeeded every 2-3 years
ToxicityHas a milky sap that’s toxic to humans and animals
USDA Plant Hardiness Zone 5-11

How to Care for Euphorbia japonica

Here are the most crucial care conditions for Euphorbia japonica that you must know to keep it alive and healthy.

How to Water Euphorbia japonica

Considering its large caudex, Euphorbia japonica is impressively drought resistant. This means that the plant only needs the soil to be moist for it to thrive. Additionally, the plant is a slow grower, so it requires less water per unit time in the long run.


Here’re two crucial watering tips for this plant:

  • In summer, water more frequently as the soil tends to dry out pretty fast. I follow a simple rule of soil test. Just feel the top soil of the potting mix. If 1-2 inches of soil is dry then it time for watering. Despite Euphorbia japonica is a succulent plant, continuous under-watering when the temperatures are high can cause drooping.
  • During winter, water sparingly and only when the soil has dried out completely. Wetting the soil can bring a whole lot of fungal infections to the plant, so this is a practice you should avoid.

Euphorbia japonica Light Requirements

The plant thrives in conditions where there’s plenty of sunlight. When growing the plant indoors, choose a position where it’ll get enough sun exposure. Go for a spot near a window or somewhere else where there’s enough sun exposure.

Please note that plenty of sunlight does not mean scorching sun. If exposed to such conditions, the plant will be stressed and you’ll just make it harder for it to survive.

Temperature

The ideal temperature range for Euphorbia japonica is 70-80°F (21-27°C)

Here are tips you should consider:

  • Avoid extreme temperature conditions such as scorching sun as this will do more harm than good to your plant 
  • If you take your plant outdoors during the door, ensure you bring it back indoors when the temperatures fall below 50°F (10°C). Although the plant is relatively hardy to cold, anything below 50°F can stress it

Humidity

Even though most tropical plants thrive in humid conditions, Euphorbia japonica is particularly sensitive to low humidity.

This plant will thrive in normal room humidity conditions. 40-50% is the best range for this plant species. If the humidity is consistently low the plant will turn brown and crispy.

The ideal growth conditions for Euphorbia japonica are between 50-70% relative humidity, according to the plant’s needs. 

The relative humidity in most homes fluctuates between 40- 60% on a daily basis. I recommend that you get a small humidifier and place it near your Euphorbia japonica in order to increase the humidity in the surrounding areas.

In order to adjust for dry circumstances, some websites advise spraying plants. Misting, on the other hand, has no major effect on humidity and may potentially contribute to the development of fungal infections in the environment. Do not spray your plant as a result of this situation.

Euphorbia japonica Soil

It is recommended that Euphorbia japonica be planted in well-draining soil to minimize root rot and overwatering. A soil mixture consisting of 70% decomposed granite soil and 30% perlite would be ideal for growing Euphorbia japonica. 

If you have cacti or succulent potting mix, it’ll be more than excellent for the plant.  If you want to go DIY, you should make a mix whose grittiness and drainage are almost identical to that of a cacti mix.

Here are example materials you can use to make a growing mix for this plant:

  • Regular potting soil 50%
  • Sand 30%
  • Pumice 20%

When planting the plant for the first time, choose a deep pot that can hold a decent amount of the potting mix. The best time to plant Euphorbia japonica is March.

Fertilizing Euphorbia japonica

This cactus plant species do not require fertilizing that much. However, if the soil is poor, it’s recommended that you give it a boost with a water-soluble nutrient-balanced fertilizer.

Before using your fertilizer, always ensure that it’s sufficiently diluted- aim at half its strength.

Pruning and Trimming

Euphorbia japonica is a dwarf planet with a slow growth rate, so it’ll barely require pruning or trimming. If you wish to make the Euphorbia japonica grow in a particular form, you can prune/ trim it to your liking.

How to Repot Euphorbia japonica

The plant will thrive just fine in its planting pot for the first year. However, it’s recommended to repot the plant after every two or three years.

Here are other indicators that the plant needs repotting:

  • If the plant has started outgrowing its pot
  • When the plant roots have started growing out of the drainage holes
  • If the potting mix is completely dried out or excessively drained

The Step by Step Process of Repotting Euphorbia Japonica

  • Pick a pot that’s 2-3 inches (5-7.5cm) larger than the bulbous plant’s base
  • Make drainage holes on the new pot just like in the current pot 
  • Cover the drainage holes with a porous material such as a coffee filter 
  • Layer the pot with the potting mix or soil 
  • Remove the plant from the current pot and loosen its roots
  • Add the plant to the larger pot. 
  • Water the plant after a week. Don’t worry if the plant appears wilted for the first few days.

Tips to Consider when Repotting Euphorbia Japonica

  • Don’t water the plant until a week is over. This will give the plant roots that were damaged during the repotting process enough time to heal
  • Repot the plant in early spring when growing has just kick-started.

Propagating Euphorbia japonica

Luckily, Euphorbia japonica can be propagated using the stem cuttings method. You only need to be a little careful when handling the plant as it contains a toxic milk sap that can be irritating to the skin.

Here’s the best procedure to follow:

  • Use a sharp and clean knife to take the cuttings. 
  • Allow the cuttings to shrivel up before putting them in the well-drained soil
  • For faster sprouting, you can brush the cuttings with a rooting hormone before placing them in the ground
  • The plant may take a long period to sprout, but you can speed up the process by maintaining the soil temperature at around 77°F.

Bonus tip: Wrap the new pot in a bag to keep moisture in but allow the soil to breathe once a day. This will cause much faster sprouting.

Common Euphorbia japonica Problems and How to Fix Them

Pests

Remarkably, the plant is not seriously prone to pests. However, if pests were to invade this plant, they would be spider mites, whiteflies, mealybugs, and scales.

There are some natural or homemade methods to eliminate pests. For spider mites, mealybugs neem oil spray works great. 

You can also use rubbing alcohol to deal with them. If the infestation is very low you can handpick the insects and get rid of them. 

Diseases

This plant species is not excessively susceptible to diseases. Nevertheless, the diseases that affect Euphorbias may affect this plant species too.

Below are the common diseases that may affect Euphorbia japonica :

Overwatered Euphorbia japonica
Overwatered Euphorbia japonica

Root or stem rot

Rot can occur if you overwater the plant, especially during winter. Usually, there’s nothing significant you can do for fungal infections. 

While there’s an option of getting fungicides to counter the infections, it would be better to isolate and destroy the affected plants to prevent the spread of the infections to other healthy plants.

Powdery Mildew

Powdery Mildew is one of the diseases that may affect your Euphorbia japonicas. The condition is characterized by a powdery film occurring on various sections of the plant.

Common causes of mildew are poor lighting conditions, lack of crucial nutrients in the soil, and high humidity levels. The standard strategy to battle this condition is isolating the plant and applying neem oil.

Drooping

Since this plant species is lightly-leaved, drooping is not a significant problem. Even so, the plant may droop due to these reasons:

  • Extreme root and stem rot
  • Excessive sunburn
  • Flooding the hardy plant with water

Leaves Yellowing

Yellowing of leaves is a condition that indicates that your Euphorbia japonica is stressed. Stress mainly occurs if you overwater or underwater it. Besides temperature fluctuations, lack of nutrients, diseases, and pests can cause yellowing of euphorbia japonica. 

Brown spots on Leaves

Brown spots are primarily caused by sunburn or photo-toxic poisoning. The latter occurs when the plant is exposed to the direct sun immediately after applying insecticides. 

Injuries when handling the plant may also cause brown spots on the leaves.  With proper care and handling of this plant, this will be a rare condition.

Leaves Curling

Like many succulents, Euphorbia japonica’s leaves will curl due to one or several of these reasons:

  • Overwatering 
  • Underwatering
  • Overexposure to direct sunlight
  • Lack of enough light 
  • Poor draining soil

Euphorbia japonica Toxicity

As is the case for all plant varieties in the Euphorbia genus, the Euphorbia japonica has a milky sap that can be very toxic if ingested.

Children are likely to fall victim to this, so be extra strategic with keeping the plant indoors.

If you’re allergic to latex, you’re highly prone to react to the Euphorbia japonica’s milky sap. For this reason, always wear gloves when handling this plant. 

Euphorbia japonica is also toxic to pets (cats and dogs), so keep the plant out of their reach. 

Final Thoughts 

The Euphorbia japonica is a great indoor plant that would form a unique addition to the plants’ collection you already have. The plant is pretty easy to care for, so it’s suitable for beginners as well as seasoned plant keepers. 

If you properly look after this hardy plant, following the easy care details provided in this guide, no pests or diseases will invade your plant. Simply put, you’ll have the smoothest experience keeping this plant species.

Find a reputable shop locally or online to buy your Euphorbia japonica, follow these highly effective guidelines and cultivate this plant as a professional.