Scientific Name — Euphorbia japonica
Common Name(s) — Pineapple Euphorbia or Cocklebur
Plant Family — Euphorbiaceae
Background
Euphorbia japonica is a dwarf succulent hybrid bred in nurseries from two plants native to South Africa. It has lightly-leaved branches growing from a central caudex, or bulbous root system.
This slow-grower likes a lot of water in the summer and very little in the winter. As the top of the plant grows, the caudex beneath it becomes a hardened brown stalk.
Growth Requirements
Sun
Euphorbia japonica does best in full sun, at least 5 to 8 hours a day. Avoid intense afternoon sun. Grow outdoors in light shade or indoors in a sunny window with southern exposure and direct sun.
Temperature/ Humidity
Euphorbia japonica prefers warm temperatures in the 70s and 80s. It can become stressed if left in conditions of extreme temperatures or intense sun.
These plants are relatively cold-hardy for Euphorbias, but only if they are kept very dry. For best results, bring this plant inside as soon as nighttime temperatures dip below 50 ºF.
Water
Thanks to its large caudex, Euphorbia japonica is a drought-tolerant plant. However, for best results in the summer months, it should be watered fairly often. Don’t let the soil totally dry out. When you do water, the soil should be slightly moist but not wet.
Water sparingly throughout the winter. During this season, the soil should be allowed to dry out entirely before watering thoroughly.
Soil/Roots
Euphorbia japonica prefers a sandy mix that drains sharply. Cacti or succulent potting mix is great.
You can amend a regular potting soil with sand or pumice up to 50% to improve grittiness and drainage.
Flowering
Euphorbia japonica produces small yellow-green flowers during the spring and summer. Potted plants and plants grown indoors may not flower.
Fertilization
Euphorbia japonica does not require fertilizer, though it can be added to give container-grown plants a boost or to supplement poor soil. Apply a water-soluble, balanced fertilizer monthly, diluted at half strength.
Propagation
You can propagate Euphorbia japonica from stem cuttings. Take great care when cutting these plants as they contain a sap that can be highly irritating if contacted with skin.
Allow your cuttings to callous for several days before dusting with rooting hormone and placing in soil.
Health
Diseases and Pests
Euphorbia japonica is not prone to pests. Though not super common, they are more likely to fall victim to bacterial or fungal infections. Affected plants may need to be destroyed to prevent the spread of disease to other nearby plants.
Root rot can also be a concern and is triggered by overwatering. Always err on the side of underwatering.
Maintenance (pruning, legginess, repotting)
Little maintenance is required to grow Euphorbia japonica.
The deep, bulbous roots of this plant often require a deep pot. Once planted, they will be happy in the same pot for several years. Repot at most once every two to three years.
Toxicity
All Euphorbia plants contain a poisonous sap that is very toxic if ingested and highly irritating to the skin.
Keep out of reach of pets and children. Wear gloves and take great care when handling this plant.
FAQs
Can I follow the same care plan year-round with my Euphorbia japonica?
With this plant, it’s better to adjust your watering depending on the season and moisture conditions. Although it has a caudex for storing water, Euphorbia japonica is happiest receiving some water during the summer months so the soil remains moist.
In winter, you can water much less often. The soil in the cool months should dry out completely between waterings.
Should I be worried if my Euphorbia japonica never blooms?
No, it’s common for your indoor Euphorbia japonica to remain flowerless. If you want to give it the best chance of blooming, monitor sunlight and water closely. Even then, flowers may not appear.
Can my Euphorbia japonica live all year outdoors?
Only if you have very mild winters and summers that aren’t extremely hot. These plants do not tolerate temperatures below 50 ºF, and strong afternoon sun in the summer can also be harmful.
