SoutheasternSoutheastern PalmsPalms Volume 20-2 1 www.sepalms.org Visit SPS on Facebook Southeastern Palms is the journal of the Southeastern Palm Society (SPS). SPS, founded in 1992, is the southeastern United States (north-of-Florida) chapter of the renowned International Palm Society. Members are devoted to growing hardy palms and other subtropical plants. Editor and Tom McClendon, St. Marys, Georgia article submissions [email protected] Design and layout Jeff Stevens, Apison, Tennessee Production Phil Bennion, Marietta, Georgia Mailing and Johnny Cochran, Douglasville, Georgia missing issues [email protected] Address changes, membership and Will Taylor, Athens, Tennessee payment questions [email protected] Online membership renewal and bookstore www.sepalms.org Southeastern Palms Will Roberds: 1992–1997 editors emeritus: Alan Bills: 1997–2000 Jeff Stevens: 2001–2008 Front Cover: A well-grown sago palm (Cycas revoluta), the cycad easily available to most of us, at the Anniston Museum of Natural History in Anniston, Alabama. Photo: Jeff Stevens. 2 Contents Volume 20-2 December 2012 4 Cycads: Carboniferous-Era Creature Comforts by Joe LeVert – Cones, male and female – Germination and growth – Culture – Pests – Recommended cycads 16 Coffee: Cycads’ New Best Friend? by Tom Broome – Treatment for cycad aulacaspis scale (CAS) – Ask the barista – Treatment in the landscape 2012 is the Southeastern Palm Society’s 20th Anniversary! Correction In the article “Natural Variation in Sabal palmetto” (Volume 20-1), the photos for Figures 4 and 5 were mistakenly reversed. We apologize for the error, which will be corrected for the web version of the issue. 3 Cycads:Cycads: CarboniferousCarboniferous--EraEra CreatureCreature ComfortsComforts Article by Joe LeVert Augusta, Georgia 4 Cycads:Cycads: CarboniferousCarboniferous--EraEra CreatureCreature ComfortsComforts Cycas guizhouensis in the garden of Hayes Jackson, Anniston, Alabama. (Figure 7): Photo: Jeff Stevens 5 ycads are some of the most striking plants grown throughout C the warmer areas of the world. Even though they aren’t the most cold-hardy plants around, they are so beautiful and interesting in a primitive way that they are well worth the attempt to grow them in pots or in the ground. Most palm growers are eventually going to want to try growing cycads as well. To the untrained eye, many cycads appear to be palms because of their pinnate leaves emerging out of a single trunk. The common name for the most common cycad in the Southeast is the sago palm (Cycas revoluta), but when cycads bear their reproductive organs, the difference between palms and cycads is all too clear. Cones, male and female Cycads are primitive higher plants which bear cones like pines or cypress trees. Like people or hollies, cycads are male or female. The plant itself does not reveal its gender in its overall appearance—no distinctive colored plumage to distinguish between the boys and girls as in birds. Only when a cycad produces its cones is the gender obvious. In the case of the genus Cycas, male cones look, well, pretty male if you know what I mean. Female cones in Cycas resemble a fuzzy brain (Figures 1 and 2). Pollination in cycads is generally accomplished by insect larvae which don’t come with the plants. I am sure that the thousands of insects that will take up residence in a Cycas female cone probably spread a little pollen around as does the occasional slug. But to really do the job, pollination has to be effected by taking a ripe male cone in hand (pollen falling out of the scales on the sides) and then dusting the female cone for several days. Pollen can also be collected from the male cone on a piece of paper and then mixed with water and a little soap and then squirted into the female cone with a turkey baster. This is about the only way to get a good seed crop on Cycas taitungensis, since 6 Figures 1 and 2. Male and female cones of Cycas taitungensis. No prizes for guessing which is which. Photos: Joe LeVert the female cone scales remain tight and impenetrable. Female cones are ready to receive pollen when they take on a distinctive yeasty odor and feel slightly warm to the touch. Months later, the female cone will open up revealing the relatively large and frequently brightly colored seeds. For Cycas revoluta, Cycas taitungensis, and Cycas panzhihuaensis, the seeds will be ripe in November in central Georgia. Germination and growth In a way, cycads are the marsupials of the plant family: even when the seeds are technically ripe, the tiny embryo is still mature and requires an after-ripening period before germination can occur. This after-ripening usually takes place over several months. After collection, Cycas seeds should be stored at room temperature with their “skin” (schlerotesa) still attached for four or five months. Planting them before the embryo has matured will only add more risk of fungal infection of the seed since the seed would be sitting in a moist medium for such a long time. When it is time to plant the seed (April and May for fall- collected Cycas seed), the seeds should be soaked in water for 7 several days with a daily change of the water. The outer coating will soften and can be removed since it contains germination inhibitors. Seeds can then be laid on their side buried halfway in a sterile mixture, such as perlite and peat that will hold some moisture, but will not support fungal growth. High day and night temperatures will trigger germination within three months, but I have seen some seed delay germination for a couple of years. A test wiggle of the seeds will reveal whether the first root has emerged and anchored the seed. Cycads will also germinate outdoors and naturalize. I have Cycas revoluta and Cycas taitungensis babies popping up around the yard and I have seen chance seedlings of Zamia integrifolia in Saint Marys, Georgia. Young plants can be transplanted when they have two leaves. Deep pots work well since they provide the young cycad plenty of space to develop a deep tap root. Culture Cycads are not usually picky about fertilizer, but they will definitely grow faster and more robustly when they are fertilized heavily. I have been using a cycad fertilizer from Tom Broome of The Cycad Jungle in Lakeland, Florida, and it has made a huge difference the overall health of the cycads that I grow. Occasionally a cycad that is suffering from manganese deficiency will enate leaves that look like they have been burned when they emerge. A fertilizer that is high in nitrogen and manganese will correct this problem. I have only seen this malady on the coast and in Florida. Pests Cycads can have some insect problems, notably scale. Scale insects are pretty sneaky and by the time you realize that they’re all over the place, well, they’re all over the place. Cycads frequently provide lots of hiding places for scale on the backs of leaves, the growing point of the plant and on the roots. Happily, 8 there is a pretty effective cure for scale: coffee grounds. Generously dumped around the crown and trunk of the plant, the caffeine seems to kill scale pretty well. It makes your cycad smell like breakfast is being served also. I have seen roaches eating tender young cycad leaves as well, but just about anything will kill a roach so spray away if you encounter this problem. Newly transplanted Cycas plants that have been dug should be kept dry for several weeks to avoid any root rot problems. Recommended cycads Here is a list of recommended cycads for Zone 8 and warmer. Because these cycads themselves are generally hardier than the foliage, many can be grown in the warmer parts of Zone 7 if you are: ● Willing to provide protection from cold ● Willing to provide a microclimate ● Or are willing to tolerate loss of foliage during most winters. All will do best if they do not have frost on the foliage, especially when the sun rises in the morning. That means they should be in morning shade or under high pines, for example. Ceratozamia hildae (Figure 3) from Mexico grows at relatively high elevations in dry oak forests. It has proven to be quite hardy in central Figure 3. The bamboo cycad, Ceratozamia hildae. Photo: Tom Broome. 9 Figure 4. A trunked specimen of the sago palm, Cycas revoluta, growing in Fernandina Beach, Florida. Photo: Joe LeVert. Alabama, though the leaves are sensitive to frost formation. Best where frost won’t touch the leaves, so plant it under evergreen oaks or pines. Cycas revoluta, the sago palm (Figure 4), is the most commonly planted cycad in the world, and almost ubiquitous in the warmer areas of the Southeast. It’s commonly planted for a 10 Figure 5. Cycas taitungensis in full flush in the garden of Joe LeVert, Augusta, Georgia. Photo: Jeff Stevens. reason: it’s beautiful, resilient, easy to grow, and long-lived. Cycas revoluta is easily identified by its keel-shaped leaves, which form a distinct V. Cycas taitungensis, the prince sago, (Figure 5) is somewhat more cold-hardy than its cousin Cycas revoluta, although its foliage will be lost at around 20 to 22°F. If heavily fertilized, this 11 Figure 6. Cycas panzhihuaensis growing in the garden of Hayes Jackson, Anniston, Alabama. Photo: Jeff Stevens. cycad has been documented as having three flushes of growth in one season, making it a very fast grower. Cycas panzhihuaensis (Figure 6) is a species that carries flat leaves much like Cycas taitungensis but is smaller and not as fast growing. From a slight distance, the plant has a bluish cast that is very attractive.