cactus family is one of the most common in house plant collections. There are many
members of the family and they are well adapted to indoor culture. the plural for
cactus is cacti. Cacti are dicots that have a fleshy, green, photosynthetic stem,
the cladophyll, and leaves modified as spines. One group of cacti, Pereskia, has
true leaves that are shed during long droughts. Some cacti are spineless and others
have their spines modified as coarse hair. Most cacti produce perfect flowers.
The flowers vary in size but are showy, usually delicate, and very attractive. Most
cacti are terrestrial but some are epiphytes. Many cacti can be grafted and the
grafts can be made across genera.
Cephalocereus senilis is the
old man cactus because it is covered in white,
is the peanut cactus because of its clusters of
short, spiny cylindrical branches.
The genera Echinocactus,
Notocactus, Rebutia and
are all called barrel cacti for their barrel-like shapes.
Echinopsis multiplex is the
Easter-lily cactus. It has the shape of
a barrel cactus and produces long, upright, pink or white, fragrant, trumpet-like
flowers. It flowers freely.
Epiphyllum oxypetalum is one of
the large, trailing or cascading cacti called night blooming cereus. (Hylocereus
and Selenicereus are also known as night
blooming cereus.) Day blooming cultivars of Epiphyllum
are known as the orchid cacti which produce attractive flowers in many interesting
sizes, shapes and colors.
The genus Mammalaria is very large, containing
hundreds of species, many of which are cultivated as ornamentals. The genus gets its
name from the numerous mammary-like or breast-like protuberances occurring in lines along
the stem. Some common mammalarias are the old
lady cactus, golden stars cactus,
feather cactus, powder puff cactus, lady
finger cactus, thimble cactus and rose pincushion cactus.
Mammalarias often cluster in masses.
Opuntia is a large genus that contains the pad
cacti or prickly pear cacti since the
cladophylls are pad-shaped and the fruit are the edible prickly pears. The
cholla is a form of Opuntia that has cylindrical
stems and vicious spines. Bunny-ears
is a pad cactus with spineless pads covered with bright golden tufts.
is a genus of cacti that produce large spines as well as normal leaves.Pereskia grandifolia
The genus Schlumbergera contains the
Christmas cactus, Thanksgiving cactus
and Easter cactus, each named for the season during which it blooms.
Thanksgiving cactus had been classified as Zygocactus, but is not put together with the
Christmas cactus in Schlumbergera. These cacti have soft, wide green cladophylls
that appear as joints of the stem.
General Care of Cacti:
||Most cacti are tolerant of very hot
temperatures but grow well at room temperature. Some, such as Christmas cactus and
orchid cacti, flower better when exposed to cool or cold temperatures, but they can not
take freezing temperatures. Many of the opuntias are very cold tolerant and found
growing wild in some of the northern states.
||Well drained medium is essential.
The media recommended for succulents work well for the cacti. A few types, such as
the orchid cacti and Christmas and Thanksgiving cacti, grow better with more organic
matter in their medium.
||Cacti should be watered thoroughly and
then allowed to dry down between waterings. A few, such as the orchid cacti, grow
best in high humidity and benefit from misting or wetting the cladophylls.
||Most cacti grow best in bright
light. They reach maturity more rapidly and flower more freely in bright
light. They will tolerate moderate light but do poorly in low light. A few,
such as Christmas cactus and the orchid cacti will burn in hot, bright light typical of
summers in the southwest. the Christmas cactus, Thanksgiving cactus and orchid
cactus all flower best when exposed to short days, long nights. The Christmas cactus
often fails to flower if it does not get a short day, long night treatment coupled with
cool temperatures in early fall.
||Cacti seem to grow slowly and attempts to
promote faster growth with fertilizer tend to fail as over fertilization
makes the plants
weak and susceptible to disease. Cacti should be fertilized lightly in spring and
summer and little or no fertilizer applied in fall and winter. Nitrogen is
especially problematic when given in excess.
|pests and problems:
||Cacti have insect pests as do other
plants. Mealy bugs seem especially fond of cacti and can destroy the plants.
Over watering or poorly drained containers can lead to rot of the roots. Stems may be
attacked by organisms that cause areas to decay.
||Cacti need very little grooming.
||Cacti are propagated by seeds, separation
of pups or offsets and stem cuttings. Allowing stem cuttings to cure a few days in
air before sticking in the propagation bed will reduce rot. Cacti may be
grafted. They have wide graft compatibility and it is not unusual for a cactus such
as the Christmas cactus to be grafted to Pereskia, Opuntia or Cereus.