How to Grow Crown of Thorns From Cuttings
Propagating the Christ Plant
Euphorbia milii, also known as crown of thorns, Christ thorn and the Christ plant, is an ideal decoration at Christmas and Easter.
Arrange small pots of crown of thorn cuttings on tabletops, across mantels or at place settings.
You can even give crown of thorn cuttings as gifts. If you propagate it carefully, you're sure to have plenty of E. milii to share.
Taking Crown of Thorn Cuttings
To raise crown of thorn plants from cuttings, lop off short pieces of new growth with a sharp knife, razor blade or bypass pruner. The cut pieces should be short, anywhere from three to six inches long, with only the very end leaves left in place.
Take cuttings when the most new growth is available, preferably in spring or summer. Be sure to take more cuttings than needed, just in case some do not root.
Dealing with Sap
Crown of thorns is poisonous, so be sure to keep it away from pets and children. When cut, it exudes a milky sap, a sort of latex, that can cause skin irritation—even blindness.
To avoid getting crown of thorns' sap on your skin, wear gloves when taking cuttings. Some people have a strong reaction to the sap, breaking out in a dermatitis similar to that produced by poison ivy (Ombrello). If the sap does come into contact with your skin, wash it off with warm, soapy water (Toogood 246).
To harden the sap and prevent it from running, place cuttings in water and spray down the plant from which they were taken with water as well. Before placing the cuttings in growing medium, allow them to dry (Ombrello).
Choosing a Growing Medium
Once the crown of thorn cuttings are dry, set them in a slightly moist rooting medium.
A good growing medium for starting shrubs and climbers in general consists of equal parts peat moss and either sand or perlite (Ombrello; Toogood 95). You could also use equal parts peat moss and bark.
For a potting mix with exceptional drainage, combine equal parts bark, peat and perlite. Or, start crown of thorn cuttings in florist's foam (rockwool) or all sand (Toogood 95; Stewart).
If you're short on space, you could start E. milii in spagnum peat moss rolls. To make a peat roll, cut a strip about two feet long and six inches wide from a black plastic garbage bag. Cover the strip in moist peat moss. Then place the cuttings on the peat about three inches apart. The leafy top of each cutting should stick out free of the peat and the plastic liner.
Once the cuttings are in place, carefully roll up the strip and secure it with rubber bands. Set the moss roll in direct sunlight. Water it from the top to keep the cuttings moist. Covering the peat roll with a cloche of some sort will also help retain moisture (Toogood 155).
Whatever medium you choose, be sure to keep it moist but not wet. Otherwise, the cuttings could rot rather than root.
Transplanting the Cuttings
In three to six weeks, when the crown of thorn cuttings have begun to sport new growth, transplant them.
If the cuttings are small, transplant then into a soil-less potting mix. Otherwise, regular potting soil is fine (Bryant 99-100).
Have you ever started a plant from a cutting?
Tips for Taking Cuttings
Increase your chances of successfully propagating plants from cuttings:
- Use a sharp, clean cutting tool. (Blades may be cleaned with a solution of 9 parts water & 1 part bleach.)
- Take cuttings from new growth.
- Take cuttings from healthy, disease-free plants.
- Take cuttings in the morning.
- On all but hardwoods, cut on the diagonal.
- Take extra cuttings. If more root than you need, you can always give the new plants away (Smith 74).
- To encourage rooting, dip the cut end in root-forming hormone powder.
How Christ Thorn Got Its Name
According to legend, Euphorbia milii's thorny stems made up the crown worn by Christ at his crucifixion, and some evidence suggests that E. milii may indeed have been used. Its stems are quite pliant and can be easily fashioned into a circle, in spite of their sharp thorns. Also, although native to Madagascar, the plant had probably been brought into the Middle East by traders prior to the time of Christ (Ombrello).
Bryant, Geoff. Plant Propagation A to Z: Growing Plants for Free. Buffalo: Firefly, 2003.
Ombrello, T. "Crown of Thorns." UCC Biology Department. Plant of the Week. 2 Nov. 2012. Web.
Smith, Miranda. The Plant Propagator's Bible. Emmaus, PA: Rodale, 2007. Print.
Stewart, Martha. "Pruning and Propagating Crown of Thorns Plants." Martha Stewart. Web.2 November 2012.
Toogood, Alan, ed. Plant Propagation. New York: DK Publishing, 1999. Print.
© 2012 Jill Spencer