EUPHORBIACEAE
SPURGE FAMILY
INTRODUCTION: The common houseplants in the
Euphorbiaceae include shrubs, herbs and cactus-like plants. Most produce a milky sap
which may be poisonous. The flower clusters are usually subtended by colorful
bracts. In nature many euphorbs have leaves for a short time and lose them during
long periods of drought. Most also have a distinct rest period and can be damaged by
watering or trying to stimulate growth when they are in rest.
The genus Acalypha is a semi-woody plant with
bright, copper-colored leaves. Its common name is the copper leaf. Many cultivars have been
developed and they vary in size, leaf color and leaf variegation. Copper leaf is a
popular landscape plant in warmer parts of the country but also common as a house plant.
Crotons
are in the genus Codiaeum. They are shrubs that have brightly colored leaves, often many colors in one leaf. The leaves have many interesting shapes.
Variegated patterns include spots, stripes, streaks, blotches, etc. Bright light is
essential for rich color development in the leaves. Some crotons are large and used
as hedges or specimen plants in warm landscapes. San Franciscos is another
common name sometimes used for the crotons.
Poinsettia is
in the species Euphorbia pulcherrima. It is an excellent house
plant and one that can be grown on and brought into flower year after year. In
nature most poinsettias become large shrubs. If they are to be maintained in
containers either choose a large container or practice pruning to keep the plants in
bounds. Poinsettias require short days, long nights to trigger flowering. If
protected from lights that would cause long days, short nights, most will come into color
in time for Christmas. To get color earlier they should be covered a few hours each
day to shorten the length of day.
Other members of the genus Euphorbia are common
as house plants. Euphorbia splendens is the crown of thorns, a small, shrubby plant with
heavy development of thorns. It has clusters of small flowers which are especially
interesting when they appear in the heavy thorny growth. Crown of thorns has a
distinct rest requirement and should not be watered when it is in rest. Euphorbia
grandidens is the bigtooth or staghorn euphorbia, a very distinctive plant.
Devils
backbone is Pedilanthus tithymaloides. It gets its
name from the zigzag stems. Dwarf and tall cultivars exist and there are several
variations in the leaves. This plant has succulent stems, variegated white, green
and red leaves and bright red flowers. When the flower buds appear the have the
shape of a tine red bird sitting in the top of each stem. Consequently, another
common name for this plant is red bird or red bird cactus.
General Care of Euphorbs:
| temperature: |
Average room temperature is good. Many plants in this
family grow and flower best when it is cooler in winter, but most could not survive frost
or freezing weather. |
| medium: |
A well-drained mix is best, for example, the media
described for succulents above. |
| water: |
With a well-drained medium these plants can be watered as
other plants would be watered, but let them dry a little between waterings. Also
recognize the rest period that often precedes the flowering period or that may follow the
flowering period and water sparingly if at all during this time. |
| light: |
In nature these plants would be in bright light.
Therefore, for best growth put them in a well-lighted window, in direct sunlight if
possible. |
| fertilization: |
Fertilize sparingly. Most of these plants can
easily outgrow their space. If lower leaves turn yellow it is a good sign that they
are running out of nitrogen and need more fertilizer. |
| pests and problems: |
Mites are among the most common pests of these plants,
but aphids, mealy bugs, scale and white fly can also become problems. If
over watered
the roots will likely rot. If this happens, withhold water for a while and wait for
the plants to develop new roots. |
| grooming: |
Remove old, discolored and disfigured leaves. Prune to
keep them in bounds and make the plants denser in appearance. Prune poinsettia back
and repot in early spring if it is to be grown on to be flowered another time. |
| propagation: |
Stem cuttings is the most common means of
propagation. Most benefit from allowing the milky sap to dry in the air before being
stuck in the rooting medium. |
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