Cycads are ancient, palm-like, evergreen
gymnosperms (cone-bearing plants) of the Division Cycadophyta.
Represented by three families—Cycadaceae, Stangeriaceae, and Zamiaceae—the cycads are composed of approximately 200 species in 11
genera—Bowenia, Ceratozamia, Chigua, Cycas,
Dioon, Encephalartos, Lepidozamia, Macrozamia,
Microcycas, Stangeria, and Zamia.
Although many cycads superficially resemble
palms, these two groups of plants are in no way related. In fact, cycads
are more closely related to pine trees than to palms. During the age of
the dinosaurs cycads were the most abundant plants on Earth, whereas
palms did not show up on Earth for another 150 million years.
Cycads are dioecious plants, which means that
there are separate male and female plants. Female plants produce seeds
and male plants produce cones full of pollen. Many of the cones on
cycads are highly ornamental, like the bright red cones of Encephalartos
ferox (see below).
One of the reasons that cycads have survived for
so long is that they can grow in harsh conditions. Many cycads naturally
grow in pure sand or even on bare rock. Some can withstand hard freezes
every year, as well as snow. Others live in areas that receive no more
than a couple of inches of rain per year.
Dioon edule is probably the most
cold-hardy of all the cycads. In the 1989 freeze, parts of Lakeland, FL,
got down to 17°F. Most king sagos were completely defoliated, while D.
edule plants only experienced tip burn.
Many cycads are also salt tolerant. For example,
in a particular habitat in Mexico, Dioon plants hang over a cliff
and are constantly assaulted with salt spray from the Gulf of Mexico.
With our sand- and limestone-based soils here in
south Florida, it can be difficult to grow some types of plants.
However, the majority of cycads thrive here. As a result, cycads make
perfect, easy to maintain plants for our landscapes. In fact, one cycad
species is native to Florida. The common name for the plant is "coontie",
which is a Seminole name. These plants are adapted to the Florida
weather and thrive in our sandy soils.
Even though there are
more than 200 cycad species, only four are commonly planted in south
Florida: Cycas revoluta (king sago) and C. rumphii (queen
sago; mistakenly called C. circinalis [Hill, 1995]) are generally
specimen plants, often growing quite large; Zamia maritima
(cardboard ‘palm’; recently changed from Z. furfuracea [Schutzman
& Dehgan, in press]) is commonly incorporated into raised planting
beds; and Zamia floridana (Florida coontie; mistakenly known as Z.
integrifolia, Z. pumila, Z. sylvatica, or Z.
umbrosa [Schutzman & Dehgan, in press]) is used as a small
shrub, under-story plant, or groundcover. The main reason that cycads
are underutilized in landscapes in south Florida is that most species
are not available.
The primary objective of
this article is to discuss landscaping practices as they relate to
cycads in south ‘Florida Landscapes’—i.e., landscapes that
help reduce non-point source pollution and conserve water by adhering to
the principles of the Florida Yards & Neighborhoods (FYN) program.
Although they are unrelated, palms and cycads
are generally thought to be in the same category of landscape plants
because they have a similar appearance and because many believe they
have similar culture requirements. Although the former statement is true
to some extent, the latter certainly is not. A secondary goal of this
article is to illustrate some of the reasons that cycads should not be
treated like palms.
Yards & Neighborhoods
The University of Florida’s FYN program
provides educational outreach activities designed to enlist homeowners
and other stakeholders in the battle to reduce non-point source
pollution and to enhance Florida’s environment by improving landscape
management practices. This section will examine practices involving
cycads in south ‘Florida Landscapes’, with respect to the nine
principles of the FYN program.
Right Plant, Right
Place— Learning the culture requirements and site preferences
for each cycad species being considered for a landscape, and then
conducting a site evaluation are two very important steps in creating a
south ‘Florida Landscape’. General culture information for most
cycads can be found in Jones (1993), but a general rule of thumb is that
nearly all cycads require well-draining soil, and most are sensitive to
root rot when over-watered. Therefore, they should not be planted in low
or wet areas or in poorly draining soil.
require less water than many other landscape plants and most can
tolerate dry spells without irrigation. As mentioned above, cycads
should always be planted in well-draining soil and should never be
Appropriately—The only published fertilization recommendations
for cycads are those of Broome (1997), who suggested that, since most
palm fertilizers are low in nitrogen, cycads generally do not perform
well with such products. The following recommendations are based on
Broome’s (1997) article.
In the early stages of
growth, cycads push a single leaf at a time on a fairly regular
schedule. After the plants reach a certain size, each consecutive flush
begins to contain more leaves. When cycads reach the next threshold
size, the plants change from a continuous to an episodic growth pattern
(Robbertse, 1995). Since small cycads exhibit continuous growth, they
benefit from a continuous release fertilizer, such as a 360-day,
plastic-coated 18-6-8 with micro-nutrients. When the plants switch to
episodic growth, they require a different formulation at approximately
quarterly intervals to coincide with leaf flushes. A product labeled
24-7-8 plus micronutrients, with about half of the nitrogen in a
fast-acting form, works best for larger cycads.
benefits of mulch are numerous and include conserving soil moisture,
moderating soil temperature, discouraging weeds, and preventing damage
to plants from mowers and line trimmers. Organic mulches have the added
benefit of improving the limestone- and sand-based soils of south
Mulch should be applied 3-4 inches thick around all cycads and
reapplied as necessary.
Recycle Yard Waste—The
key to this principle is to reduce municipal solid waste by converting
cycad leaf debris into mulch or compost. Cycads generally do not produce
as much leaf debris as palms and do not need to be pruned like many
trees or hedges. Therefore, they make good landscape plants with respect
to this principle.
Manage Pests &
Diseases Responsibly—Most cycads are relatively free of pests
and diseases; this makes them welcome additions to a south ‘Florida
Landscape’. One notable exception is the aulacaspis scale epidemic of
king and queen sagos in south Florida. The causal organism, Aulacaspis
yasumatsui, is a white scale insect pest introduced to the U.S. from
Thailand a few years ago (Howard et al., 1996). This scale
primarily infects cycads of the genus Cycas. Left untreated,
infected plants will die. The recommended course of action in a
‘Florida Landscape’ is—whenever possible—to remove infected
sagos and replace them with species that are resistant to this scale
The most important
disease of cycads is stem and root rot, which is usually caused by
over-watering or by planting cycads in soil that does not drain freely.
This problem is easily circumvented by carefully choosing planting
locations and by watering efficiently.
Source Pollution—With respect to cycads, the simplest way to
reduce non-point source pollution is to choose species with low
fertilizer and water requirements and few pests and diseases (see
to the toxins in their leaves and seeds, cycads do not represent an
attractive food source for most forms of wildlife. In fact, cycads are
considered pest plants in some parts of the world because livestock
often get sick or die from eating the foliage and/or seeds (Jones,
1993). Rodents do not appear to be affected by these toxins, however,
and the flesh around the seed (called the sarcotesta) of some cycads is
a delicacy for squirrels and rabbits. Cycads also attract interesting
insects. For example, a recent experience by the author in a private
cycad garden in Sarasota suggests that large cycads are highly
attractive to lightning bugs, which can put on an impressive show at
dusk when in large numbers. Another insect that is attracted to certain
cycads is the atala butterfly (Eumaeus atala), a rare south
Florida endemic whose sole food source is the Florida coontie (Culbert,
Waterfront—Since cycads cannot be recommended for planting
near water, an effective general recommendation for this principle is to
establish a 20-foot-wide “No Application Zone” along the entirety of
the waterfront and to construct raised beds or dig swales to prevent
storm water from running off into surface waters.
Cycads Recommended for South ‘Florida Landscapes’
Cycads can be
broadly categorized into two groups: those that live in hot and/or dry
areas, and those that live in rainforests. Due to their high drought
tolerance, low nutrient requirements, and minimal pest and disease
problems, only cycads in the former group are recommended for south
Although many such
cycads are well suited to the soil conditions and climate of south
Florida, most species were traditionally unavailable except to the avid
cycad collector. However, much interest has been generated in cycads in
the last few years through several new books and numerous new societies.
As a result, supply of unusual cycads in wholesale nurseries in Florida
has tripled in the last five years (Broome, 1998).
maintenance’ cycads that grow well in south Florida and that are
either widely available or will be within a few years are Ceratozamia
hildae, C. kuesteriana, C. latifolia, C. robusta,
Dioon edule, D. mejiae, D. spinulo-sum, Encephalartos
ferox, E. gratus, Zamia floridana, Z. loddigesii,
and Z. vazquezii. The attractive characteristics and general
culture requirements for each are provided below (adapted from Broome,
1998; Hubbuch, 2000; and Jones, 1993).
||Ceratozamia hildae, or the bamboo cycad, gets its
name from the upright habit of its leaves, which contain
clustered, ‘bow-tie’ leaflets and can attain a height of seven
feet. This cycad prefers partial shade, but can be grown in
moderate sun or in deep shade. It can become mature in as little
as four to five years with proper care.
|Ceratozamia kuesteriana is a cold-hardy cycad from
Mexico with a short or subterranean stem and brown emergent
leaves. Because it is one of the few cycads that is completely
unarmed (i.e., lacking all spines and prickles), this
species makes a good accent plant near walkways, where most people
would not normally want to use a cycad. It prefers a shady
location with well-drained soil and will attain a spread of five
||Ceratozamia latifolia is one of the best landscape
plants in the genus. It prefers to be in the shade to look it’s
best. It has proven to be very cold and frost hardy. It grows
fairly fast and reacts well to fertilizer applications. This plant
will eventually attain a seven-foot spread. There are variations
of this species, but most have beautiful red or reddish-brown
|Ceratozamia robusta has thin, green leaflets and
green emergent leaves. It has proven to be one of the most
cold-hardy of the genus. This plant can attain a spread of nine
feet over time. It can grow in the sun or in shade, and reacts
well to fertilizer applications. It is much less common than many
others in the genus.
||Dioon edule is the most widely available, as well
as the most-cold hardy of the uncommon cycads grown in Florida.
This species prefers sandy conditions in full sun, but performs
well in virtually any soil type with good drainage. It has a high
tolerance to salt and has the general appearance of the king sago,
except with lighter green foliage. Some varieties have lavender,
pale-blue, or pale-red emergent leaves. Old plants have multiple
trunks and can reach 6-8 feet in height.
|Dioon mejiae is a small to medium-sized cycad that
develops a trunk to three feet tall and ten inches across, often
producing offsets at the base. Young leaves are light green with
very long white or golden hairs. These emergent leaves harden off
to become rigid, dark green, slightly spiny mature leaves. This is
a tough species that will withstand considerable exposure to sun
and short periods of drought. This species should also be
considered as a replacement or alter-native for the king sago in
||Dioon spinulosum, a native of the lowlands of the
Sierra Madre Oriental mountains in Mexico, is the largest of all
American cycads, with multiple trunks reaching heights of up to 30
feet. Mature specimens bear numerous stiff, light green leaves
that can reach six feet in length. This species is an attractive,
easily grown, and popular plant for the subtropics, preferring
partial shade and tolerating a wide range of soils. It should be
considered as a favorable replacement or alternative for the queen
|Encephalartos ferox, from South Africa, is one of
the most sought-after and unusual cycads in south Florida. This
species has glossy, dark-green leaflets that resemble holly leaves
and mature plants bear large, bright-red cones. This cycad prefers
a semi-shady area and can attain a spread of nine feet.
||Encephalartos gratus is one of a large group of
highly collectable cycads from South Africa. All require bright
light and well-drained soil, but may need some supplemental
irrigation in dry weather. It is a relatively fast-growing cycad
and can reach immense dimensions. Other species in the genus also
make good landscape plants for south Florida but are generally
rare or expensive.
|Zamia floridana is the native Florida coontie. It
grows throughout the state, but exhibits a high degree of
variation from place to place. The leaflets range from long and
narrow to short and wide, and overall heights range from two feet
(southern, Miami-Dade County) to five feet (northern, ‘Palatka
giant’). The coontie is a popular landscape plant that is
especially attractive in borders and as a groundcover. It can be
grown in full sun or partial shade. Coonties have an underground
stem and dark, glossy green leaves forming a graceful crown.
Large, reddish-brown cones are borne near the surface of the soil.
Male cones are lance-shaped; female cones are more rounded and
much larger overall.
||Zamia loddigesii is an extremely
tough and drought-tolerant cycad from Mexico. It is related to the
common cardboard ‘palm’, but has much narrower leaflets. Its
light green leaves can grow up to three feet long and the plant
can grow to be three feet across. It prefers to grow in full sun
but can tolerate partial shade. This cycad can be used as a small
shrub or accent plant.
|Zamia vazquezii (commonly called Z. fischeri),
resembles a fern and is sometimes mistakenly sold as one. This
cycad prefers to grow in partial shade and can be used as a small
shrub or a large groundcover. It can have green or brownish
emergent leaves and can grow up to four feet tall and four feet
information on the Internet has dramatically increased in recent years.
Anyone interested in this ancient group of plants can now subscribe to
e-mail lists and participate in online discussion forums. Numerous
websites through-out the world also contain information on cycads. The Virtual
Cycad Encyclopedia (VCE), on the website of the Palm & Cycad
Societies of Florida (http://www.plantapalm.com),
is a fairly comprehensive online resource for cycads. The VCE also
contains an extensive list of links to other cycad-related websites.
Broome, T. 1997. What fertilizer should I use on my cycads? The Palm
Review (Newsletter for the Central Florida Palm & Cycad Society)
Broome, T. 1998. Uncommon cycads best suited for the Florida landscape. Proceedings
of the Florida State Horticultural Society 111:203-204.
Culbert, D. F. 1995. Florida coonties and atala butterflies. Fact Sheet
ENH 117, Institute of Food and Agricultural Sciences, University of
Florida Extension. http://edis.ifas.ufl.edu/MG347
K. D. 1995. The genus Cycas (Cycadaceae) in the Indian region,
with notes on the application and the typification of the name Cycas
circinalis. Taxon 44:1-9.
F. W., T. Weissling, and D. Hull. 1996. New armored scale insect
introduction in Miami area. Tropicline 9. http://www.ftld.ufl.edu/index2.html
C. 2000. Are the king and queen dead in south Florida? Virtual Cycad
Encyclopedia, Palm & Cycad Societies of Florida website. http://www.plantapalm.com/vce/misc/dioon.htm
D. L. 1993. Cycads of the World: Ancient Plants in Today’s
Landscape. Smithsonian Institution Press, Washington, D. C.
H. 1995. Leaves on cycad cones. The Journal of the South African
Cycad Society 43:27-30.
B., and B. Dehgan. In press. Taxonomic problems and solutions in
Meso-american Zamia (Zamiaceae, Cycadales). Proceedings of the
International Symposium on Cycad Biology (Cycad 99), Miami, FL.
T. J., F. W. Howard, and A. Hamon. 1999. Featured creatures: Cycad
aulacaspis scale. University of Florida and Division of Plant Industry
Publication Number EENY-96. http://ifas.ufl.edu/~insect/orn/palms/cycad_scale.htm