Some Common & Uncommon Cycads for Central Florida

• Dioon edule
  Of all the cycad species Dioon edule is probably the hardiest and easiest cycad to grow. I have never seen this species with insect problems, and it is very tolerant of a variety of soil conditions. Dioon edule is also one of the longer living cycads, where a single stem can live to be 1500 years old, and will attain a stem height of 10 feet. Dioon edule is an average sized plant that will normally have a six foot spread. In many ways, it is very similar to the king sago, or Cycas revoluta. The leaves are a little lighter green, and are more rigid than the king sago. I have found it to be one of the most frost hardy species in my collection. During the freeze of 1989, I had 17F at my nursery. All my king sagos were either defoliated or showed leaf damage. None of my Dioon edule plants had even the first sign of tip burn. From what I have been told, this species will get leaf burn at 14F, and trunk damage when experiencing temperatures in the single digits. This species comes from Mexico with a habitat ranging from just south of Texas to Vera Cruz in central Mexico. Because of this, there are several variations as far as leaf types, and cold hardiness. The tolerance of low temperatures will vary depending on which variation you have, but all should be considered very cold hardy. As far as leaf types is concerned, they can have leaflets that are spread apart, close together, or even slightly over lapping. Dioon edule can have green, red, silver, and even purple emergent leaves. This means that the leaves will emerge a certain color, and once the leaves harden up, they will change to green. This is common in many cycad species, and the most colorful plants are highly sought after by collectors. Dioon edule prefers to be grown in full sun, but can tolerate some shade. It is not very fast growing. Even when it is fertilized regularly, you should not expect more than two flushes of leaves per year on the average. Cones become receptive to pollination in our area in either October or November, and seeds are usually ready the next November. Once the cone falls apart, the seeds can usually be planted immediately or with an over ripening period of only one month. Dioon edule is a good choice for the first time cycad enthusiast and is readily available at all our sales. A plant like this will be something that you can enjoy growing for the rest of your life, as well as handed down to many generations to come.
• Ceratozamia hildae
  Is also known as the Bamboo cycad for it's upright growth habit. Because of this it can be planted in many areas where other more "spreading" cycads cannot. This mature specimen is at Leu Gardens, Orlando and is another terrific choice for nearly all of central Florida - hardy into the low 20's, perhaps beyond.
• Encephalartos horridus
  One of the $$$ South African "blue" cycads. This specimen @ Selby Gardens, Sarasota. For some reason the blue Encephalartos will develop cones but do not set seed in Florida.
• Stangeria eriopus
  Native to South Africa this mature specimen growing at Leu Gardens, Orlando. The foliage is almost fern like in appearance, especially when new & soft. This is an understory plant perfectly suitable for shady areas but it can take some sun during the course of the day.
• Zamia integrifolia
  A.K.A. the Coontie. Our native cycad comes in several forms; this is the largest, known as Palatka Giant. Also known as Zamia floridana or mistakenly Z.pumila, another species entirely.
• Ceratozamia kuesteriana
  This is one of the cycads that is perfect for growing in central Florida. This plant comes from the state of Tamaulipas, in Mexico. The ground there is poor, so it can tolerate growing in our sandy soil here in Florida. I have found that this species is very cold and frost hardy. I had some plants out in the open during a freeze that had a low of 20F, and a blanketing frost, but none of the plants showed even a hint of frost damage. It has a subterranean stem, so the plant can survive temps in the lower teens. I have seen leaves and exposed stems get damaged at 17F. It makes a great landscape plant because it is one of the only cycads that does not have any spines on the leaflets, or the petioles. Because they are "unarmed", they can be planted near traffic areas. They attain a five to six foot spread, so they don't get to large for most landscape applications. They can be planted in the shade or full sun, but they look their best in light shade to give them the best color. I have found that they also produce seeds better when grown in the shade. These cycads are unique because they have brown emergent leaves. This means that when the new leaves come out, they are brown, and turn to green as they harden up. During this period of growth, some leaves and leaflets will turn green at different times so that the plant will have a variety of colors for a few weeks. As a landscaper, I have found that these cycads look very nice when they are surrounded with Aztec grass, a variegated border grass. The white grass and the brown leaves have a really nice contrast that looks good in the landscape. Both these plants perform well in the shade, so they can be used as understory plants, amongst plantings of oak trees or large palms. I have found that these plants perform moderately to fertilizer applications, and will usually produce leaves two to three times a year. As long as the soil drains well, the plants can tolerate a great deal of water, but on the other hand can be also grown in a xeriscape situation. All cycads are on the endangered species list. The most endangered species are on appendix 1, where the least endangered plants are on appendix 3. All cycads are on either appendix 1 or 2. All Ceratozamias, including C. kuesteriana are on appendix 1. In habitat, there are an estimated 1200 mature plants. The locality has been made into a national park and little poaching is happening, so these plants are fairly safe for now. They produce seeds very easily in Florida, and it is not uncommon for a female to produce a cone that will hold more than 200 seeds. Older plants can form a cluster, so it is possible for a large plant to produce up to 1000 seeds in one season. There are at least a dozen individuals in Florida who have small colonies for seed production, so these plants should easily be found for sale by cycad collectors. It would be a great plant for any novice cycad collector to grow. It can be grown almost anywhere in Florida, but until people start getting familiar with this species, it will only be seen in private collections and botanical gardens.
• Encephalartos ferox
  An excellent candidate for wide cultivation in our region. This is a "green" leafed Encephalartos which in Florida, perform much better than the "blue" Encephalartos. The green plants do set seed here (note male cones in center of plant). This specimen is growing in mainland Vero but there are larger specimens farther north & inland.