Japanese spindle, also called Japanese euonymus, is an outdoor flowering shrub that can also be grown as a houseplant. These are fairly hardy plants that can tolerate lots of conditions indoors and make great plants for a beginner houseplant parent. Regular water and bright light in the growing season is the key to keeping the Japanese spindle plant happy. This plant is considered toxic to humans and animals if ingested.
|Common Name||Japanese spindle, Japanese euonymus|
|Botanical Name||Euonymus japonicus|
|Plant Type||Flowering shrub|
|Toxicity||Toxic to humans and animals|
Can You Grow Japanese Spindle Inside?
The Japanese spindle is easy to grow indoors as a houseplant as long as you place the plant in a room with bright or indirect sunlight or even strong artificial light that mimics sunlight. It's highly adaptable to many conditions, even average home temperatures and humidity.
How to Grow Japanese Spindle Indoors
Lots of bright, indirect light is good for this plant indoors. Placing the plant in direct sunlight can cause leaf scorch which will turn the leaves white. The plant is best suited for a window with an eastern exposure. Or, place the plant a few feet away from the bright sunny light of a southern or western window. It is a good idea to rotate your Japanese spindle houseplant every few months to expose all sides of the plant to the sun.
Temperature and Humidity
The average room temperature is fine for the Japanese spindle. The plant likes to receive average warmth with temperatures ranging from 60 to 85 degrees Fahrenheit. Keep the plant in cool but temperate conditions during winter. Euonymus japonicus does prefer lower humidity levels, so an average humidity level of 30 to 60 percent in the home would suffice (higher humidity is better for tropical plants). In the winter, however, the plant may do better when the indoor humidity is in the higher average range.
Make sure the plant's soil in its pot drains well—if your plant becomes waterlogged, it will suffer. During the growth period from spring to fall they should be watered regularly. You can scale back their water during the winter.
They can be fed at the beginning of spring with a well-balanced fertilizer before growth starts. Then feed once monthly. Japanese spindle may also benefit from the application of a root stimulator.
Pruning and Maintenance
These plants will benefit aesthetically from yearly pruning, and it’s also good for their health. These plants will benefit aesthetically from yearly pruning, and it’s good for their health as well. Keep them pared back by pruning in spring,
Container and Size
Choose a fairly large pot for a Japanese spindle houseplant. The container should be able to retain moisture yet have plenty of drainage holes. A plastic or glazed ceramic pot would work fine to hold moisture. However, make sure the pot is hefty enough so it will not tip over since this tree can grow fast. The pot you choose should be about the same size or slightly larger than the pot the plant came in from the garden store.
Potting Soil and Drainage
Though they can tolerate lots of conditions, their soil should be well-drained and moist. A typical potting soil mix should be fine for this houseplant.
Potting and Repotting Japanese Spindle
This plant grows well in pots but when it doubles in size, it should be repotted. Japanese spindle will likely need to be repotted every year in the spring. Water the root ball in advance to make the process easier, then remove the entire plant in one piece. Trim the roots to loosen up the ball, then replace in a new pot and backfill it with potting soil.
How fast does Japanese euonymus grow indoors?
This plant is a moderately fast grower and can add 1 to 2 feet annually to its height outdoors and may be similarly so indoors depending on conditions. Pruning is advised to keep the size of your houseplant in check.
What plant pests are common to Japanese euonymus?
They are susceptible to euonymus scale—watch out for unusual markings on the leaves. If your plant suffers from scale, a good pesticide can provide relief.
Is it easy to propagate Japanese euonymus?
The plant propagates well from cuttings, which should be taken at the end of the growth period in late summer. Cut a stem from the plant right below a node, which is the point from which a leaf or bud grows, and then replant it in a mixture like peat moss and perlite or sand. Make sure to keep the cuttings misted, warm, and well-lit in their infancy.
Euonymus japonicus. North Carolina State University Extension.
Euonymus. Pet Poison Helpline.