CROWN OF THORNS (euphorbia milii) - Information & Care Instructions

Posted on 29 Jul 00:33

CROWN OF THORNS (euphorbia milii)

This Crown of Thorns is a spiny, succulent bonsai that flowers nearly all year. The common name alludes to the legend that the crown worn by Christ, at the time of his crucifixion, was made from stems of euphorbi milii.
The botanical name comes from Euphorbus, the Greek physician of King Juba II (about 50 BC to 19 AD).  King Juba II was the first person to find this succulent-type Euphorbia; he named it after his physician.  Milii comes from Baron Milius, once governor of the island of Bourbon, who introduced the species into cultivation in France in 1821.

The growth & habit of Crown of Thorns is more like tropical foliage plant, then a true succulent.  This is a truly tough plant; in the wild it can take about anything.  Though it prefers moderation; it can survive relatively dry conditions, overly wet conditions, a temperature range between 39 and 105 + deg F, part shade to full sun and a variety of soil types.  Remember bonsai are more sensitive, so Moderation is the keyword.

Available in a number of colors; our current plants are Salmon colored.  It's flowers are small; the brightly colored modified leaves (bracts), found just beneath the flowers, are quite attractive.

How To Take Proper Care Of Your Indoor Bonsai Tree

Bonsai is the reproduction of natural tree forms in miniature. This art form has its origin in Japan and China where it has been practiced for centuries. Bonsai are grown in pots and are totally dependent on you for their care.  With proper care, your bonsai will remain healthy, beautiful and miniature for many years to come.
Since your bonsai is a living miniature tree, it will increase in beauty as it matures through the years.  The instructions below are just the basics and, therefore, we recommend that you purchase one of the many fine books available on the subject.


The Crown of Thorns will thrive indoors in high light.  It will appreciates being kept outdoors during the spring and summer.
When night time temperatures drop below 45 degrees, we suggest that you place the tree indoors, on a windowsill or on a table in front of a window.


Once nightly lows begin approaching the 40 degree mark, it is time to bring your indoor bonsai inside.
The ideal indoor location is on a window sill facing south.  An east or west exposure is second best.  A northern exposure will work, but will necessitate the use of "grow lights" to provide sufficient light to keep your bonsai healthy.  Four to six hours of sunlight per day should suffice.  If you can provide more light , so much the better.


Though Crown of Thorns can tolerate both over and under watering, it is best to pay close attention and apply water before the soil appears dry.  Never allow the soil to become completely dry or allow the bottom of the pot to sit in standing water.  
Water should be applied until it begins running out of the holes in the bottom of your pot.  It doesn’t really matter “how” you water your tree, but rather that when you are finished the tree has been well watered.  Try to avoid allowing water to collect in the center of the flowers by limiting the watering the flowers.


During the cold months, when your bonsai is inside, we recommend placing it in a shallow tray filled with a layer of gravel with water added. This provides extra moisture around the tree as the water evaporates and reduces the amount of moisture lost to modern heating systems.


Fertilizing is also necessary if your bonsai is to remain healthy and beautiful. Since your bonsai is growing in such a small amount of soil it is necessary to replenish the soil's supply of nutrients periodically. Any general-purpose liquid fertilizer will do fine and is available at most garden centers. We suggest that fertilizers be used at half their recommended strength. Fertilizer should be applied at least once a month except during winter. Your bonsai will also respond well to foliar feeding, with a water-soluble fertilizer applied every other month as a spray.


This brief explanation of basic care does not cover training. Training deals with the art of bonsai and should be thoroughly understood before undertaking -- or left to a professional. However, most of the true bonsai trees you find have already been through their training period, thus requiring only periodic trimming and pinching to remain miniature.


Trimming and pinching keep your tree miniature. Pinch and trim back the new growth to the farthest safe point. Never should all of the new growth be removed. A little should be left to sustain the health of the tree. Tropical and sub-tropical trees used for bonsai will require periodic pinching and trimming throughout the year. Since different trees grow at different rates, it is necessary to evaluate each tree’s rate of growth and adjust your trimming and pinching to accommodate it.


Re-potting must be performed periodically on all bonsai when their root system has filled the pot.  The reasons for re-potting are to supply your tree with fresh soil, and to encourage a more compact root system.
As a rule, most deciduous trees require re-potting every two or three years, while evergreens only need to be re-potted every four or five years.  Since trees grow at different rates, this schedule will not always hold true, therefore, you should examine your tree's root system each year to determine if it has become pot-bound.
In most cases, the potting process is easy and safe if performed properly and at the right time of the year.  Re-potting should be done in mid-summer.  The tree, along with all of its soil, should be removed from the pot.  The outer and bottom most fourth of the tree's root mass should be removed.  This is done by raking the soil away, then pruning back the roots.  In most cases, it is not good to prune back more than one fourth of the tree's root mass.  After this, the tree can be placed back in its original pot or into another.
The pot should have screen placed over the drainage holes. Then a thin layer of small gravel is placed in the bottom of the pot for drainage purposes.  On top of this gravel is placed the new fresh soil.  Place a layer of well-draining soil which is sufficient enough to elevate the tree to its previous height in the pot.  After placing the tree back in the pot, the area left vacant by the pruned root mass should be filled in with fresh soil.  This fresh soil should be worked in around and under the root mass in such a manner as to avoid leaving any air pockets.
After re-potting, your bonsai should be thoroughly watered. This can be achieved by submerging the entire pot in a tub of water.  Moss or other ground covers can be used to cover the surface of the pot to help prevent soil erosion when watering.


Since your bonsai is a tree in miniature, it can be treated for insects and diseases the same as any other tree.  If you discover any insects or diseases, visit our website where you will be able to obtain the necessary products to eliminate the problem.