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Gardening
© St. Petersburg Times, published December 27, 2002
Connie Hawthorn of Carrollwood wrote with a number of questions about palms. I'll start by providing some general information on palms and then get to her specific questions.
The most important factor for a healthy palm tree is good soil. The type of soil determines how many nutrients and how much water the plant receives. Our sandy soil is very good for palms.
Another vital component of palm tree care is proper fertilization. Palm trees require specially formulated fertilizers. Purchase a fertilizer formulated just for palm trees.
There are palm-specific fertilizers available that release nutrients very slowly to provide consistent, targeted feeding.
In general, four factors should be considered when choosing a palm tree for your property. The first factor is the size of the tree at maturity. Remember, the little palm for sale at a local nursery might reach a height of 50 feet or more as an adult tree. It can overpower the rest of your property, interfere with overhead lines and underground conduits and, perhaps, threaten buildings if the tree is planted too nearby. Make sure that the size of your palm at maturity is in keeping with your needs and overall landscape design.
The second factor is temperature. Most types of palm trees will not tolerate freezing weather and even a short bout of frost may weaken a tree and leave it vulnerable to insects and disease. Check with your local nursery or tree expert for advice if you're unsure about the growing conditions of a specific palm in our area.
The third factor is sunlight. Not all varieties of palm trees are equally sun tolerant. Some varieties, in fact, prefer shady conditions to full exposure. Keep this in mind when considering the kind of palm tree that would be best for you.
The final factor is water. While palm trees have long been associated with desert conditions, in the wild, they are generally found near abundant and continuous supplies of water. If you are thinking about planting a palm tree on your property, make sure the tree will receive adequate water and be prepared to water a newly transplanted tree frequently while it acclimates.
Planting palm trees is similar to planting other kinds of trees. Nursery-grown palms are generally sold either potted or balled and burlapped. Try to plant your tree shortly after purchase. If there is going to be any time lag between purchase and planting, make sure that the tree's root ball is kept moist but not soaking. When transporting and handling palm trees, use care. The bark is easily damaged, and damaged areas leave the tree vulnerable to insects and fungus. The best time of year to plant is during the warmer months when the soil temperature is at least 65 degrees.
Dig a hole wide enough to fit the root ball with plenty of room to spare. Twice as wide might be a good rule of thumb. The hole should be just deep enough so that the tree is planted at the depth at which it was grown. Do not plant the tree any deeper as this may deprive the roots of nutrients and water. After situating the tree in the hole backfill with the freshly dug soil.
When the palm tree has been planted, build a soil barrier around the circumference of the hole to form a dam that will hold water. Then lay down a 3-inch layer of organic mulch around the tree.
Frequent watering is crucial for newly planted palm trees. Daily for about the first two weeks and then tapering off over several months as the tree establishes itself. Use a bubbler or arrange a hose to slowly soak the area around the tree. It is important not to allow the soil to dry out, as this will severely weaken your new palm. In the absence of regular rainfall, periodic watering is essential. As they grow, the older fronds of palm trees will turn brown, die and, eventually, fall off. For aesthetic reasons, you may wish to speed the process along a little by pruning off the dead fronds. Use some caution when pruning a palm tree. Prune only the dead fronds and remember not to cut too close to the trunk. In the case of a large tree, this is a job that should be left to a tree maintenance specialist.
Hawthorn had a number of questions about her queen palms (Arecastrums), which are very popular in this area. This palm is a native of Brazil, has graceful, plumy leaves and can grow more than 30 feet. They are attractive when used as street trees, but they aren't very long-lived. Arecastrums should be planted where there aren't high winds because their leaf stalks can kink or bend and take away from the beauty of their leaves. A. Romanzoffianum (Queen Palm) is often grown under the name Cocos plumosa. Its variety australe is smaller but just as pretty. You can pull off the bark (the dried ends from the fronds) as the tree grows. Do not cut off all the fronds.
Another of Hawthorn's questions concerns the sago palms, Cycas revolute. It is one of the most primitive living seed plants. A rugged trunk, topped with whorled feathery leaves has lead to the common name "sago palm." But it is actually related to conifer and Ginko trees, all cone-bearing plants that trace their origins to the ancient flora of the early Mesozoic era. Often called living fossils, cycads have changed very little in the last 200-million years.
While various species of cycads can be found throughout the world, the subtropical C. revoluta is native to the Far East and has been used as a choice container and landscape plant for centuries. The growth habit of Cycas revoluta displays an upright trunk with a diameter of 1 inch to 12 inches depending on age, topped with stiff featherlike leaves growing in a circular pattern. Rather than continuously adding foliage, sagos produce a periodic flush of new leaves, called a "break."
Eventually, offsets begin to grow at the base of the specimen, and occasionally in the crown. The addition of offsets provides a source of new plants. Regardless of age or size, Cycas revoluta is one of the easiest plants to grow, indoors or out, by beginner or expert. This subtropical adapts to a wide range of temperatures from 15 to 110 degrees Fahrenheit, accepts full sun, thrives with attention and tolerates neglect.
The rate of growth is slow, but they are extremely long-lived, and old specimens can grow in curious ways. They may end up multitrunked and multibranched. The soil should be well drained and rich in humus although these durable plants seem to grow in almost anything. In the landscape, be sure to plant sagos slightly above the soil line and not in a hole, which retains water. They prefer to be on the dry side rather than the wet side.
Their water and fertilizer needs are related to the amount of light available. Unlike most plants, which can wilt when dry or turn yellow from lack of fertilizer, cycads give little indication of when to water or feed. Generally, they should be treated as a cactus and watered when almost dry.
If grown in a container, allow the soil to become almost dry and then water thoroughly. If the plant is receiving morning or afternoon sun or temperatures are warm, sagos may need to be watered at least weekly. Plants grown in low light or cool temperatures may need water every few weeks or so. If planted in the landscape, water when dry, but do not keep continuously wet. Established plants can easily survive drought conditions.
Fertilizer is generally applied during spring and late summer. Sagos growing in partial sun should receive an average rate as listed on the container; those in low light should receive only one-quarter rate. Too little plant food is far better than too much. If organic or slow release fertilizer is used, do not allow any to fall into the plant crown, which is protecting the formation of future leaves. Old leaves may turn yellow from over watering or too much fertilizer. New leaves may turn yellow from excess fertilizer or poor soil conditions.
The biggest concern with sagos seems to be their wicked leaves. Those that are planted too close to a sidewalk can stab guests as they arrive. This is a problem of Connie's. Unfortunately there is no way to prune these plants to inhibit their size. This is a prime example of planting in a location that the sago has now outgrown. Sagos of any size do not take kindly to transplanting. If you have "pups" (small plants) growing from the base of your sago, these can be removed and planted elsewhere. I recommend you plant them in a container to establish some roots before planting in your yard.
Hope this helps with your palms and cycads. I'll cover even more questions about popular Florida plants in my next column.