Acalyphas (Chenille Plants)


Paula Szilard

Most of us are familiar with the Spurge family, scientifically known as the Euphorbiaceae, a diverse family of plants  which exude a toxic milky sap when cut. Many plants in this family grace our gardens and our homes. The Poinsettia is in this grouping as are the Crown of Thorns, jatrophas and codiaeums (crotons).  Yet fewer people are aware that Acalyphas (pronounced acaleefa with the accent on the next to the last syllable) belong in this family.

This genus has roughly 430 species, but only a small number are horticulturally important.  Many are shrubs, even trees, in tropical and subtropical areas.  All have serrated, entire leaves.  All have catkin-like flowers.  Some acalyphas have traditionally been used as medicines.  Recently one of these traditional uses has been corroborated by modern medicine.  Researchers at a Nigerian university found antimicrobial constituents in the leaves of two acalypha species—A. wilkesiana and A. hispida. An acalypha ointment was found to be an effective treatment of superficial fungal skin diseases.  

Some acalyphas are prized for their attractive, virtually perpetual catkin-like flowers.  Others have very uninteresting and insignificant flowers, but are known for their attractive, beautifully variegated leaves.  This just underscores an old horticultural truism:  It’s a rare plant indeed that has gorgeous flowers combined with equally gorgeous foliage.

The showiest catkins, sometimes called cattails, belong to Acalypha hispida, a new Guinea native, which sometimes goes by the name ‘Red Hot Cattails.’  It is a nonstop bloomer when given enough light.  Because the catkins come out of the new leaf axils, for these plants to grow inevitably means to bloom.  The red tassle-like catkins are 8”-10” long.  There is also a white cultivar, Acalypha hispida ‘Alba,’ which is actually cream-colored.  Grown outdoors in warm climates it can become a sizeable shrub up to 11 feet tall.  As a potted plant indoors it is somewhat more restricted and can be kept fairly small with aggressive pruning.  Grow A. hispida in very bright light with part sun.

Acalypha repens, another species with red catkin-like flowers, albeit much smaller ones (only about 1-2  inches long), has very lax drooping stems and makes a good hanging basket plant. It is often known as ‘Strawberry Firetails.’ A common cultivar is “Red Fire Tails.”   For some reason I had a lot of problems trying to grow this plant until I purchased some plants in the annuals section of my garden center 3 years ago.  I don’t have a ready explanation for this, except that these plants were totally free of pests (such as spider mites and much healthier than the hanging baskets found in the houseplant section.  Previously I always experienced drying and necrosis of the leaf tips.  Don’t say it’s dry air!  My humidity levels are essentially the same as those in the DBG Conservatory.  Light conditions required are the same as for A. hispida

Another species commonly grown indoors as a container plant is Acalypha wilkesiana, sometimes called Copperleaf or Joseph’s Coat.  Originally from Fiji, this shrub now grows all over the South Pacific.   Prized for its colorful leaves, this shrub can grow to a height of 10-15 feet outdoors in warm climates.  The serrated leaves are a coppery red color with shadings of bronze, red, pink and cream.  Coloration is highly variable and depends on light.; the better the light, the better the color.  From across the room, the reddish brown tassle-like flowers are so insignificant that they look like a bit of fuzz between the leaves.  Interestingly, the red coloration in acalyphas is the result of  plant pigments known as anthocyanins, commonly found in purple vegetables.  The cultivar Acalypha wilkesiana ‘Marginata,’ for instance, is a green leaf with white edging that is overlaid with the red anthocyanin pigment.  As a result the green center of the leaf turns a dark coppery bronze and the white edging becomes pink.  What a gorgeous leaf!

There are a lot more cultivars of Acalypha wilkesiana than of A. hispida or A. repens. (I am still not sure which cultivar I have. The label said only Acalypha wilkesiana along with the word ‘Copperleaf.’)  One striking culivar is Acalypha ‘Ceylon.’  It is quite distinct with its crested, deeply serrated bronze and green leaves, edged in red.  This was another one of my success stories from the garden center annuals section.  

Acalypha godseffiana heterophylla is another A.wilkesiana cultivar. The narrow, long leaves can be either green edged in white or bronze edged in red.   They give the plant a slightly “shredded” look.

Another currently available cultivar is ‘Brazen,’ a shrubby dark bronze colored plant, sometimes verging on dark brown or black.  It’s not particularly showy, so it makes a nice background plant.  The new variety, Acalypha ‘Bourbon Street,’ came out of the “Athens Select’ program in Georgia two years ago.  It has long reddish bronze leaves with cream, pink or red edging and it’s heat tolerant. 

A sunny spot is a must if you want to maintain good leaf color.  When I ran out of space close to my west and south windows, I moved some of my plants back from the windows and the color started to fade almost immediately.

The plants can get large if you let them.   During periods of rapid growth regular pruning is a necessity.   Although mature plants grown in tropical and subtropical areas are considered somewhat drought tolerant, this is definitely not the case with potted plants grown indoors on or near sunny windowsills.  Acalyphas in containers take a surprising amount of water.  I check my soil regularly and wind up watering every 3rd day-- every other day when the weather is very hot. 

Recently I realized that the leaves on my wilkesiana were getting smaller.  I had been fertilizing my aclyphas with Dyna-Gro Liquid Grow Plant Food (7-9-5) once a month, but concluded that I needed to try something with a little more nitrogen to promote leaf growth.    I am also temporarily increasing the number of applications to two a month because I recently read that acalyphas are heavy feeders.  Maybe I was starving these poor plants!

Acalyphas are child’s play to propagate.  It’s best to use non-woody tip cuttings and take off all but 3 or 4 of the top leaves.   Mix a little perlite with some peat.  Then put it into a small 2 ½” pot.  Coat the clean-cut edge of the cutting with a little rooting powder and anchor it deeply  in your rooting medium.  Add a little water, allow it to drain and place it, pot and all, into a thin plastic bag.  Supermarket vegetable bags are perfect.  Tie loosely and place on your light stand. If you have a source of bottom heat, it should be rooted in 2-3 weeks.  If not, it will take a little longer.  Check periodically to be sure it doesn’t get too dry  .If you do not have a light stand, put it near a bright window, but shade it from any direct sun.

Although they have the reputation of being prone to spider mite infestations, I have not had serious pest problems on my plants.  (Maybe buying them as annuals was a good idea!)  My A. hispida had some scale on it when I brought it home, but several applications of horticultural oil spray have kept them under control.  Just now, after almost three years I am noticing some spider mites on my Acalypha ‘Ceylon.’  Maybe I have not had serious infestations because my humidity levels are between 60-70%.

Spider mites don’t seem to like a lot of moisture.  I am dealing with my current problem on Acalypha ‘Ceylon’ by repeatedly spraying them with strong jets of water and occasionally applying a natural pesticide with pyrethrins.

A few pest problems aside, acalyphas are very rewarding plants.  If you can give them a prominent, sunlit spot, they will light up a room at any time of the year. Acalypha hispida and Acalypha repens are especially decorative at Christmas time.