Euphorbia Lactea: Handling the Toxic Mottled Spurge

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The wonky look of Euphorbia lactea will add a character to your garden that no other plant can. It has three-sided, candelabra arms and a tall, lanky stem. The silhouette is wobbly. In fact, Euphorbia lactea nearly resembles a child’s drawing.

Adding to E. lactea’s charm are short spines along the edges. They’re small but still sharp. The whole plant is green with mottled white stripes. This inspired the common nickname Mottled Spurge.

It doesn’t seem like it, but mottled spurge is a shrub, not a cactus. This is due to the presence of sap and the absence of large flowers. Also unlike cacti, Euphorbia lactea is a tropical plant. It’s native to India, Sri Lanka, and other areas in tropical Asia.

We won’t lie, Euphorbia lactea is a challenging plant. It has specific watering needs and is dangerously toxic. Once settled in though, mottled spurge pretty much takes care of itself. It’s perfect for neglectful gardeners willing to make an initial effort.

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Quick Care Guide

Euphorbia lactea leaves
Most non-Cristata cultivars have straight, spined leaves like these. Source: Starr
Common Name(s)Mottled Spurge, Dragon Bones Tree,
Dragon Bones, Candelabra Spurge,
Candelabra Cactus, Crested Cactus, Candle
Stick Tree, False Cactus, Hat Rack Cactus,
Mottled Candlestick, Milkstripe euphorbia
Scientific NameEuphorbia lactea
FamilyEuphorbiaceae
Height & Spread2-15 feet tall; 2-5″ wide
LightFull sun to partial shade
Water“Soak and dry”; weekly during the summer
SoilWell-draining
FertilizerDiluted liquid fertilizer in the spring and
fall; low-nitrogen
Pests & DiseasesMealybugs, spider mites, powdery mildew, root rot

All About Mottled Spurge

Dragon bones has a crazy height potential of 15 feet! How tall your mottled spurge grows depends on the conditions you give it. When grown indoors in a pot, it will reach 2 feet tops. Left in the ground unchecked though, it will grow much taller.

You’ll notice the most growth in spring and summer. If you live within zones 10-11, your mottled spurge can live outdoors year-round. In these zones, it’s commonly grown as a fence or hedge plant. However, mottled spurge also makes a great houseplant. It can stay inside all year or move in and out depending on the weather.

Euphorbia lactea flowers very rarely and usually only in the wild. Its yellow-tinged flowers are considerably small and grow at the edge of the plant. You may see your dragon bones grow small teardrop leaves on the tips of the stem. Unfortunately, these cute details usually fall off pretty quickly.           

Mottled candlestick is entirely poisonous, from root to sap. If you have curious pets or children, this is not the plant for you. Be cautious when handling crested cactus. The toxic sap, called latex, will ooze from stem cuts and can irritate your skin. Gardeners should always wear gloves when handling E. lactea.

Because some varieties don’t grow roots well, the top of Euphorbia lactea Cristata is often grafted onto the base of another plant. The most common host is Euphorbia neriifolia. The combination of these two plants is named coral cactus and cleverly referred to as Frankenstein cactus.

Types of Euphorbia Lactea

The full plant of Euphorbia lactea Cristata
Where normal euphorbia lactea tends to be straight-leaved, Cristata is rippled. Source: Jardineiro

Euphorbia lactea Cristata, ‘Elkhorn’, ‘Frilled Fan’, ‘Crested Euphorbia’

This common form changes the shape of Euphorbia lactea drastically. Crested euphorbia lactea has wavy paddles that make it much fuller than the sparse original form. The edges of the stem align into an s-shape.

Variegated Euphorbia lactea

Variegation is most commonly found on crested E. lacteas. Instead of simple green and white, these varieties are painted with yellow, pink, or violet. These are especially vulnerable to direct sun and heat.

Euphorbia lactea ‘White Ghost’, ‘Grey Ghost’

This is the white variegated form. Unlike the other variegated E. lacteas, you’ll usually see this one in the upright, non-crested form. Because of the light color, this plant is extra sensitive to direct light and can be burned easily.

Dragon Bones Care

Euphorbia lactea Cristata
The Cristata form of Euphorbia lactea has a distinctive, rippled top crest. Source: vikisuzan

As mentioned, dragon bones has specific watering needs. Besides that though, this shrub is fairly low-maintenance. Here’s everything you need to know.

Light & Temperature

Full to partial sun is ideal for mottled spurge. Be cautious placing it in full sun though. When exposed to direct light and heat, it can easily sunburn. It can also be burned if exposed to bright light suddenly. When moving your mottled spurge, do so gradually so it can acclimate. 

Euphorbia lactea cannot handle frost! 40° F is the lowest temperature this plant may tolerate. This shrub grows best when it’s warm, so we recommend not testing lower temperatures.

Water & Humidity

False cactus responds well to the ”soak and dry” method, with a few exceptions. For this method, soak the soil until water leaks out of the drainage hole. Let the soil dry out completely before watering again. Because it comes from a tropical climate, false cactus handles humidity well.

During the summer, water your Euphorbia lactea at least once a week. Alternately, drastically cut down on water during the winter. Only water it once or not at all during this time.

Because of its varying water demands, you should know how to tell if your false cactus needs more or less water. When overwatered, it will turn yellow, brown, and mushy. If left unchecked, the mushiness can quickly turn to rot. Underwatered false cactus will begin to wrinkle and wilt. This plant will bounce back faster when underwatered than overwatered.

Soil

The soil needed for dragon bones is typical for any cactus or succulent. It has to be well-draining so that your plant is never sitting in water. This is vital to keeping it alive.

There are many soils out there made specifically for succulents and cacti. If you already have the materials though, you can mix your own well-draining soil. Just add one part perlite or sand to one part potting soil. After planting, regularly check that the soil is draining well and make adjustments as needed.

Fertilizer

Give your mottled spurge half-strength fertilizer every month from spring to fall. This will give it an extra boost for the growing season. Fertilizer low in nitrogen will provide the best results.

The roots of mottled spurge can sometimes be burned by fertilizer. To prevent this, dilute your liquid fertilizer to ½ or ¼ strength and apply it right before watering.

Repotting

Euphorbia lactea Grey Ghost
The ‘Grey Ghost’ cultivar of euphorbia lactea has silvery-grey leaves. Source: Cerlin Ng

When you buy it, your Euphorbia cactus will probably come in a small container and general garden-store soil. You’ll need to repot it into something bigger and better draining. Choose a container that’s about two inches larger in diameter and is heavy enough to balance out the height of your E. lactea. You don’t want it to become top-heavy and fall over.

For such a tall plant, dragon bones has small roots. This gives it the benefit of rarely being rootbound. When you remove it from the pot, gently dust off the roots and massage them out if they’re clumped together. Repot it in dry, well-draining cactus soil. It may be tempting to treat your dragon bones to a drink, but hold off on the water for a couple weeks. This will give the roots time to heal from any damage.

Because of its spines and toxic sap, safety is your top priority when repotting. Remember to always, always wear gloves! For added protection, cover your arms and legs and wear safety goggles – especially if you’re repotting a large Euphorbia lactea. If your plant has multiple stems growing close together, protect them from each other by padding them with newspaper before moving.

Propagation

When it comes to propagation by cuttings, you’ll have the best luck with the basic Euphorbia lactea. The crested and variegated forms don’t root well, so they’re often propagated by grafting. Before getting started on either, remember to cover up! You’ll be cutting into the plant, so toxic sap will definitely be present.

Take your cutting during the spring or summer, when your mottled spurge is growing the most. Using a sharp, sterile knife, slice off one of the arms where it connects to the stem. If you encounter a flow of sap here, wash it away with cold water.

After taking your cutting, dip it in rooting powder and let it dry out for a week to two weeks. Once the cut is calloused over, stick your cutting upright in the soil. Mist the soil with water or leave it dry until the roots are established. Euphorbia lactea roots best in heat, so place it outside or on a heating mat.

Grafting A Frankenstein Cactus

Grafted Euphorbia lactea Cristata crest
Grafting is a way to attach Euphorbia lactea Cristata crests to other succulents. Source: Bill Gracey

It’s a complicated process, but if you want to make yourself a coral cactus from your Euphorbia lactea, you’ll have to graft it to a Euphorbia neriifolia. Here’s how to do it:

  1. Choose an E. lactea cutting and Euphorbia neriifolia that are young and healthy and which look like they’ll fit together.
  2. Cut a V in the neriifolia, removing the upper portion to make the base of the plant.
  3. Cut a matching V in the lactea that will fit exactly into the neriifolia.
  4. Piece together the two V cuts with lactea on top. Check that there aren’t any gaps between the two, which can lead to rot.
  5. Seal the V with grafting wax.
  6. Wrap the whole graft in twine.
  7. Wait 2-3 weeks for the plants to heal and then remove the twine.
  8. Enjoy your new Frankenstein cactus!

Pruning

Mottled spurge rarely requires pruning. The only time it’s necessary is if part of the plant is rotting or otherwise injured. Simply cut back the damaged parts with a clean knife. The plant will heal by itself as long as you keep the cut section dry.

Troubleshooting

Although it’s a pain during maintenance, the sap of false cactus is efficient at keeping pests and diseases away. However, every plant has weaknesses that you should know about.

Growing Problems

If your E. lactea is grafted onto another plant, there’s a possibility that the base plant will grow stems around the euphorbia. If you like this peculiar look, feel free to let it grow. If not, simply prune back the unwanted stems.

Pests

Mealybugs are a common pest that are always hungry for succulent sap. These scale insects are small and build cottony white nests. Infestations will cause the plant to turn yellow, wilt, and eventually die.

Remove mealybugs by dabbing them with a q-tip dipped in diluted rubbing alcohol (70% or lower). Insecticidal soap is a common remedy for mealybugs, but not recommended for Euphorbia lactea as it can damage the plant.

Spider mites may also appear on your mottled spurge. These are exceptionally tiny arachnids that make small webs on plants. Wash them away with a strong spray of water. Alternatively, apply thoroughly diluted neem oil to the stem.

Diseases

Powdery mildew looks exactly how it sounds: white and moldy. Dragon bones is prone to it when there’s poor air circulation and humidity. Like every disease, it’s best eradicated early on. To remove powdery mildew without damaging your plant, wash the plant with a baking soda mixture. Dissolve one tablespoon of baking soda into a gallon of water for the perfect mildew remedy.

The most common threat to succulent-like plants is root rot. Even though it usually starts in the roots, any part of your Euphorbia lactea can fall victim to this condition. Rot begins when the plant is constantly wet – a result of overwatering and/or poor drainage. Rotted sections will become brownish-black and mushy.

If you notice even the smallest amount of rot, you’ll need to take action right away. If left to spread, the entire plant can quickly die. 

Remove your plant from its container so you can examine the whole thing. Carefully cut off any parts that are rotted. Once the plant is rot-free, leave it out of the soil to dry for several days. Once the wounds have scabbed over, replant your Dragon Bones in new soil.

FAQs

Euphorbia lactea Cristata crest
The Cristata variety’s crest can have quite colorful spined edges. Source: graftedno1

Q. I got sap on me! What do I do?

A. Euphorbia latex is very dangerous, so wash it off right away. It dries like clear glue, so ensure that you get every bit off. Even after washing, your skin may be severely irritated. If any gets in your eyes, seek medical attention immediately since it can lead to blindness. Wearing gloves is highly recommended.

Q. Why does my crested Euphorbia lactea have some branches that are straight?

A. It’s normal for crested euphorbia to revert back to its original form, although the cause is unknown. If you don’t like the appearance of the straight branches, just prune them back.


The Green Thumbs Behind This Article:

Rachel Garcia
Succulent Fanatic

Lorin Nielsen
Lifetime Gardener

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