Proc. Fla. State Hort. Soc. 111:203-204. 1998. UNCOMMON CYCADS BEST SUITED FOR THE FLORIDA LANDSCAPE TOM BROOME that would be perfect for xeriscape projects, yet alone in our o»o«> £ I g» eveiT day landscaPes- The main reason people do not use n,,u? these unusual cycads in the landscape is that they are not fa- Polk City, FL. 33868 miliar with them. Lack of supply of these cycads has also been a determining factor. In the last five years there has been a lot Abstract. Cycads have survived on this earth for over 250 mil- of interest generated by new books on the subject of cycads lion years. One reason is because they will grow where the and by the many cycad societies that have been formed all faster growing angiosperms cannot survive. They thrive in over the state. Supply of unusual cycads in wholesale nurser roots that produce nitrogen for the plant to use. For many rea- •/ are several unusual cycad species that can be grown sons, cycads are perfect for xeriscaping projects and growing ? tsuccessfully m Florida, but a good supply of these plants in Florida's sandy soils. Most of us are familiar with sagos, the landscaPe trade might be several years coming. I am cardboard plants, and coonties, commonly used in land- §oing to discuss five species that will work well in our land scapes. What about the other 250 species? Uncommon cycads scapes and either have a widespread availability already or will growing in Florida nurseries are an important resource that have in the next few years. These plants will be discussed in has been untapped by landscapers throughout our state be- the order of the most available to the least available at this cause people are not familiar with them. I will discuss five un- time. Florida3 landscaDe'lable Cy°adS that are beSt suited for the Dioon edule is probably top on the list for cold hardiness of all the cycads that grow well in Florida. After the freeze of „ , , 1989 my king sagos were totally defoliated. My Dioon edule Cycads are the oldest living, seed bearing plants left on plants did not even get tip burn at 17°F. I know of people who earth. The first fossil cycads date back 250 million years. Dur- have tested this plant down to 10°F. In habitat, these plants ing the age of the dinosaurs, cycads were the most prominent grow in sandy areas, and sometimes on rocks over looking the plant group. Around 75 million years ago the flowering plants Gulf of Mexico, also showing their great salt tolerance In fact evolved and are the most prevalent plant group today. The they will grow well in almost any kind of soil that drains well' few hundred species of cycads that exist today are a small frac- Barring any insect or pathogen damage, these plants will live tion of the species that used to exist. The cycads that are left for 1500 years with no real care at all. Dioon edule has the gen- are the ones that will survive where the faster growing flower- eral appearance of the king sago, with lighter green foliage ing plants cannot. These habitats are usually deserts and oth- These plants are available all over the state by wholesale nurs- er sandy areas or on top of stone outcroppings and in forest eries that carry other, more well known cycads areas too dark for flowering plants. Cycas taitungensis, commonly known as the Prince Sago, or Cycads have structural mechanisms that have helped the Emperor Sago is starting to be widely used in areas where them to sumve. Most have some sort of spines on the leaflets a larger, but cold hardy cycad is needed. The leaf spread of and cataphylls on the stems to ward off any animals that may the King Sago will normally be around six feet wide where want to eat them. Cycads have a specialized secondary root the spread on this species will be around eleven feet wide system called coralloid roots that grow up to the surface in- The foliage has been found to be slightly less frost tolerant stead ol down like most roots. A blue green algae grows on compared to the king, but the stems have found to be more top of these roots and help with a nitrogen fixing process that cold hardy. People have been growing these plants as a test in produces nitrogen for the plant to live on. This is why a cycad Atlanta and in central Alabama. These plants are also very salt can grow on solid rock without any nutrients. The stems of tolerant. Cycas taitungensis is probably the fastest growing cycads are also very hardy. Cycad stems have a starch content cycad on earth. If grown in full sun, and fertilized heavily of around 65%. If something happens to the foliage or if a these plants can push up to six leaf flushes per year With the part of the stem is damaged, the plant will live off the starch right growing conditions, these plants can grow from a until new leaves or new growing apexes are produced. In cer- sprouted seed to a plant with a two-ft tall stem in less than five tain habitats seasonal fires are a way of life. The stems get years. Availability is very good on this species, with more than burned but the next year new foliage emerges. Cycad stems 100,000 plants being produced each year in Florida also can be propagated by cutting them up into small pieces Encephalartos ferox is a species from South Africa that is be- and planung them separately. coming one of the most sought after unusual cycad in south The soil in Florida is mostly sand in many areas and/or Florida. This species has leaflets that resemble the leaves of a coral rock in some of the southern parts of the state. It is hard Rotunda Holly plant, making it very showy The best attribute to get many plants to grow in these areas. Use of native plants this species has is the bright red cones that are produced on and xenscaping is going to be the way of the future for land- the mature plants. A female cone can be fifteen inches tall scapers Cycads are perfect for these types of landscapes and and ten inches wide. A larger plant can produce as many as" soil conditions. Native Zamias are already being used by mu- five female cones at one time. With the dark green foliage nicipahties and road departments all over the state in great these red cones can really stand out in the landscape. I like to numbers use these plants ^^ Aztec Grass to add tQ the contrast of col. Are there any other cycads that can be used in these cases? or and texture. Encephalartos ferox prefers to grow in a semi- There are many cycad species growing in Florida nurseries shady area to look the best. The plant can tolerate tempera- Proc. Fla. State Hort. Soc. Ill: 1998. 203 tures down to 18°F, but is not very frost tolerant. If grown in quite a few people with breeding colonies here in Florida, the shade, it would be protected from these frosts. This spe- Somewhere around 10,000 seeds are produced each year in cies will attain a spread of nine feet, in only eight years of Florida, but this will have to increase if demand for this spe- proper growing. Supply of this plant is not meeting the de- cies grows in the future. mand yet but there are a dozen nurseries in Florida propa- Ceratozamia hildae, commonly known as the bamboo gating these plants from seed. cycad, has to be the most exciting new species of cycad to en- Ceratozamia kuesteriana is a cycad from Mexico that is just ter Florida. This plant grows more in a shape similar to bam- now coming onto the scene. The foliage is very frost tolerant, boo instead of having a fountain form shape like most cycads. and the stems have proved to be cold hardy down to 17°F. The foliage as well as the stem are very cold hardy, and have This is a subterranean species, so if the stem is planted below been tested in Louisiana with very good results during the ground level it would tolerate a lot lower temperatures. This 1989 freeze. Except for bamboo, there are not too many cold is one of only a few species of cycads that are totally unarmed, hardy plants that have this upright habit. These plants can be or in other words there are no spines on these plants. This used in smaller areas where sagos would be out of the ques- species would make a good accent plant near walkways where tion. The leaves on this species will attain a height of around most people would not want to use other cycads. Ceratozamia seven feet, and the leaflets are arranged in clusters that re- kuesteriana has what cycad collectors call brown emergent semble a bow tie in appearance. Ceratozamia hildae is a fairly leaves. The new soft leaves come out brown and then harden fast growing species, and can become mature in only four to up to a light green. This color change can be very attractive in five years. This plant looks it's best in partial shade but can be the landscape where contrast is needed. A single headed grown in more sun, or in deep shade.