The African milk tree (Euphorbia trigona) is native to Central Africa. This plant looks a lot like a cactus—hence its nicknames: candelabra cactus, cathedral cactus, friendship cactus, and good luck cactus—but it is actually a succulent plant. It features triangular stems, with three distinct sides seamed with ridges. The ridges are peppered with thorns and teardrop-shaped leaves. This plant stays lush and green throughout its growing season, with new growth sprouting a light green hue.
Like a cactus, the African milk tree is a long-lived plant that grows vigorously, approximately 1 to 2 feet a year up to 9 feet tall. It is often grown as a hedge due to its rapid and enthusiastic growth. When grown indoors, this plant will only grow to about half of its maximum height.
The African milk plant, also known as Euphorbia trigona, is a popular houseplant known for its unique treelike shape and milky sap. Despite being relatively low maintenance, these plants can still fall victim to some common pests. As a grower, it’s important to learn how to prevent and control infestations to keep African milk plants looking their best. In this article, we’ll cover the most common pests of these plants, ways to prevent them, and effective control methods.
Mealybugs – The Most Common Pest
The most prevalent pest of African milk plants is the mealybug. These small sap-sucking insects can occur in both outdoor and indoor plants. They appear as tiny white cottony masses usually clustered along stems and leaf joints. An infestation is evident if you see clusters of mealybugs excessive honeydew (sticky residue), and sooty mold growing on the honeydew.
Mealybugs pierce plant tissues and feed on sap This can cause stunted growth, leaf yellowing, and plant death if left uncontrolled These pests are so common in African milk plants because they thrive in the warm, dry conditions these plants need.
Preventing Mealybugs
- Quarantine new plants before introducing them to others
- Provide good air circulation around plants
- Avoid overwatering and promote dryness
- Keep plants pruned to remove excessive growth
- Monitor closely for early signs of infestation
Controlling Existing Mealybug Infestations
If mealybugs are present, take action right away. Possible control methods include:
- Manual removal – Use a toothpick or cotton swab dipped in alcohol to remove bugs.
- Insecticidal soap – Spray directly on bugs for quick knockdown. May need multiple applications.
- Horticultural oils – Smother and kill insects on contact. Less harmful to plants.
- Neem oil – Disrupts bug growth and works as a repellent. Avoid using when temperatures exceed 90°F.
- Systemic insecticides – Applied as drenches or granules. Absorbed by plants and ingested by pests.
- Natural predators – Ladybugs, lacewings, and parasitic wasps feed on mealybugs.
No single method eradicates all mealybugs. Often, a combination of methods and persistence is needed Always follow label directions when using pesticides
Scale Insects – Armored Pests
Scale insects are small, immobile pests encased in a waxy, armor-like covering. They attach themselves to stems, leaves, and branches to feed on plant fluids. Heavy infestations cause leaf yellowing, stunting, and dieback.
These insects tend to congregate on the underside of leaves and along stems. Look for bumpy crusty or cottony masses. The shape of the scale covering helps identify the species. Scales produce honeydew secretions which lead to sooty mold growth.
Preventing Scale Insects
- Keep plants healthy with proper care
- Prune infested stems
- Encourage natural predators like ladybugs and parasitoid wasps
- Monitor for early signs of scales
- Quarantine new plants before introducing to your collection
Controlling Existing Scale Infections
- Manual removal – Pick off visible scales. Use a toothbrush or cotton swab dipped in alcohol to scrub off stubborn scales.
- Horticultural oils – Smother scales by coating plants. Requires good coverage.
- Insecticidal soaps – Spray directly on insects. Kill by dissolving their waxy covering.
- Neem oil – Disrupts scale growth and repels them. Less harmful than synthetic pesticides.
- Systemic insecticides – Applied as soil drenches or granules. Absorbed by plants and ingested by feeding scales.
Getting under the protective covering is key. Combining methods helps break the scale life cycle for good.
Spider Mites – Tiny Leaf Damagers
Spider mites are tiny pests related to spiders. They feed on plant juices through needle-like mouthparts. These microscopic bugs are often overlooked until plants show signs of damage. They create fine webbing and speckling on leaf surfaces. Leaves turn yellow, dry, and drop off with heavy mite feeding.
Spider mites thrive in hot, dry conditions. African milk plants grown indoors are very susceptible because mites spread rapidly in warm rooms.
Preventing Spider Mites
- Maintain proper humidity around plants
- Avoid high temperatures and direct sun
- Hose plants down periodically to reduce mite numbers
- Introduce predatory mites which eat spider mites
- Apply neem oil as repellent before infestations start
- Monitor plants closely including undersides of leaves
Controlling Existing Spider Mite Infestations
- Manual removal – Wipe leaves down with a damp cloth to crush mites.
- Insecticidal soaps – Spray directly on mites for quick control.
- Horticultural oils – Smother mites on contact while being safe for plants.
- Neem oil – Disrupts mite growth and repels them.
- Chemical miticides – Products containing abamectin, bifenazate, or fenpyroximate. Use as a last resort.
Getting good spray coverage, especially leaf undersides, is critical. Combining methods prevents mites from building resistance.
Aphids – Piercing Pest Suckers
Aphids are soft-bodied insects that insert needle-like mouthparts into plants to feed on sap. They gather in large groups on fresh growth. Aphids stunt plant growth, curl leaves, and excrete sticky honeydew. Ants often farm aphids for their honeydew.
Aphids reproduce rapidly so early control is key. Check tender new leaves and stems where they tend to congregate. Knocking aphids off plants with a strong water spray is a good initial control method.
Preventing Aphids
- Encourage natural predators like ladybugs, lacewings, and syrphid flies
- Use reflective mulches to deter winged aphids from landing
- Coat plants with neem oil before infestations take hold
- Monitor for colonies and treat early
- Use row covers to form physical barriers against aphids
Controlling Existing Aphid Infestations
- Insecticidal soaps – Kill aphids on contact while being safe for plants when diluted properly.
- Neem oil – Disrupt aphid growth and repel them. Has longer residual effects than soaps.
- Horticultural oils – Smother and kill existing aphids. Require good coverage for best results.
- Systemic insecticides – Applied to soil to be taken up by plant roots and make plant tissues toxic to feeding aphids.
- Natural predators – Ladybugs, lacewings, and syrphid flies all feed on aphids.
Spray undersides of leaves for best coverage. Combining methods helps break the aphid life cycle.
Thrips – Small Pains with Big Damage
Thrips are tiny, winged insects that rasp plant tissues and feed on the exuding sap. They cause silver-white streaks, spots, distorted growth, and flower damage. Thrips hide in tight plant crevices so are often unseen until symptoms appear.
These tiny pests quickly develop large populations. They spread serious plant viruses, especially tomato spotted wilt virus. Immediate control is needed to mitigate damage.
Preventing Thrips
- Use blue or silver reflective mulch to deter thrips
- Install screening or barriers to keep thrips out
- Remove weeds which harbor thrips
- Rotate insecticides to avoid resistance
- Apply neem oil early before infestations establish
Controlling Existing Thrips Infestations
- Insecticidal soap – Effective against thrips when sprayed directly. Requires good coverage.
- Neem oil – Disrupts thrips growth and repels them. Better residual control than soaps.
- Biological control – Predatory mites and nematodes feed on thrips.
- Systemic insecticides – Applied to soil or foliage to be ingested by feeding thrips.
- Botanical oils – Smother thrips on contact while being safe for plants. Act as repellents.
Getting complete spray coverage is crucial since thrips hide deep inside plants. Rotate modes of action for most effective control.
Prevention Is the Best Cure
While African milk plants are susceptible to certain pests, you can avoid many issues through smart prevention methods:
- Inspect plants regularly for early signs of pests
- Quarantine new plants before adding to your collection
- Provide proper care and growing conditions
- Promote beneficial insects that prey on pests
- Apply neem oil early before infestations occur
Taking these proactive measures reduces the need for reactive pesticide use. When pest problems do occur, nontoxic methods like insecticidal soaps, horticultural oils, and biocontrols are the first line of defense. For severe infestations, targete
Overwintering
African milk trees wont survive the cold. They typically wont flourish in temperatures below 50 degrees F, so its important to plant them in the ground only if your climate allows. Potted plants need to be brought indoors when temperatures drop. Place your succulent in a room with good air circulation to cut down the humidity and set it in a brightly lit window with indirect sunlight.
Types of African Milk Tree
There is one variety of the African milk tree, Euphorbia trigona f. rubra, also referred to as Royal Red. It has striking maroon or vibrant red leaves.
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FAQ
What are the pests of the African Milk Tree?
How to care for an African milk plant?
How do you take care of a milk plant?
How to care for African milk tree?
Allow the soil to dry out completely in between each time you water to encourage healthy growth. Fertilization should be done when your African milk tree plants enter the active growing period (spring and summer). Select a balanced, half-diluted fertilizer and apply it to your plant every month is part of proper plant care food for these plants.
What pests eat African milk tree?
The most common pests are mealybugs, which enjoy infesting the African milk tree. While finding mealybugs can be a nuisance to you, there are easy steps you can take to rid your plant of them. Mealybugs leave a cotton-like residue grow on the foliage of your plant.
How do you plant African milk tree?
Positioning your plant: Place the African Milk Tree in the center of the new pot and fill it with soil. Pat the soil gently to secure the plant. Watering after potting: After potting, water the plant and place it in bright indirect light. Allow the soil to dry between waterings.
Are African milk trees good for beginners?
Help your African Milk Tree thrive in or around your house! Cacti and succulents are perfect plants for beginning plant owners because they’re easy to take care of. One of the most difficult parts of taking care of plants, especially for beginners, is knowing how often to water their plants.