Care and Characteristics
Star-Tip 1054 / Gardening Tips for successful and beautiful Landscapes and Gardens
Sago palms add an attractive tropical touch to just about any landscape. Their common name implies they are a palm, but they are not. In fact Sago Palms (Cycas revoluta)are classified as Gymnosperms which include Conifers and Ginkgo. Sagos are members of the Cycadaceae family which dates back to the Mesozoic Era. They are thought to have evolved from seed ferns millions of years ago. Why is this relevant? Because here in the Desert Southwest it is dangerous to feed them in the summer like you would most genuine Palm Trees.
◊ Introduction
◊ Sago Palms – Male & Female
◊ Potential Problems and Treatments
◊ Yellowing Leaves
◊ Leaf Sensitivity
◊ Frizzle Top
◊ Similar Symptoms – Different Causes
◊ Fertilization
◊ Balanced Fertilization
◊ Pruning
◊ Insects
◊ Cold Temperatures
◊ Watering
◊ Designing with Sagos
Introduction
Sago Palms are relatively easy plants to grow in the landscape. In the Desert they grow best in afternoon shade. Soils should be well drained with a near neutral soil pH (6.5 to 7.0). Good luck finding that!You will want mulch and amend your soil at least once a year with adequate organic material or sulfur. A liquid sulfur like Con-Grow is very effective. Sagos respond well to regular fertilization during the early growing season, March through May. (top) /
Sago Palms – Male & Female
There are separate male and female plants which form their reproductive structures (cones). The female plants produce a round fuzzy mass in the center of the leaf mass. Males form an elongated cone like structure. Bright orange seeds mature on the female plant in the fall. Plants can be propagated by removing and rooting a side shoot (pup). Also, if you want to propagate from seed, wait to collect the seed after the cones fall apart. Otherwise the embryo is not fully developed and germination is not likely. For best results, remove the outer pulp and treat the seed with Gibberellic acid to achieve a high percentage of germination. (top)
Potential Problems and Treatments
/ Yellowing Leaves: If the plant is watered too frequently, the roots will lack the ability to obtain the nutrients (and oxygen) from the soil, and yellowing throughout the plant can occur. Most often the yellowing from nutrient deficiency will show up on leaves with the most severe sun exposure. Of course if the plant is not properly fertilized or the soil pH prohibits the fertilizer from being taken up, these same symptoms will appear. Sun scorch can occur in a weakened plant.(top)
Leaf Sensitivity:
Also to be noted; the leaves of the Sago Palm are very sensitive to environment stress. They will often develop yellow speckles if battered by a hail storm or show “yellow tracks” if cold water is applied when they are in hot weather, or if injured by a falling hose for example. These types of yellowing are usually temporary and should not cause concern.
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/ Frizzle Top: One of the most frequent problems with sago palms is frizzle top caused by a manganese (not to be confused with magnesium) deficiency. It is common in high pH soils and very acid sandy soils. Early symptoms are a yellowing of the leaves, sometimes in the form of spots and eventually covering the entire leaf. New growth will emerge with a zig-zag appearance giving it the name frizzle top.If you have this problem, check the soil pH and also check the soil moisture. Too much water can cause root damage so the plants are unable to take up nutrients. To correct frizzle top, spray the leaves with liquid manganese sulfate at the rate of 1 teaspoon per gallon water monthly for 3 months. Also apply 1 to 5 pounds (depending on plant size) of manganese sulfate to the soil annually to keep the problem at bay. Even if you don't have the problem, it's a good idea to apply manganese sulfate to the soil annually in September to prevent the problem. (top)
Similar Symptoms – Different Causes
Whether the weakened condition is from disease, nutrient or the plants insufficiently establish roots, the look will be similar,, while the treatment is different. Sago Palms are a safer bet in afternoon shade as the most often will yellow in the summer until they acclimate. Proper fertilization and sulfur soil amendments will help the plant to recover from most nutrient issues. Deep infrequent watering (depending on soil type) is vital to plant health. (top)
Fertilization
If you are trying to increase plant size, fertilize established plants with a high nitrogen fertilizer like our Palm Tree Food. Remember though, the instructions for feeding on the label are for genuine Palms, avoid summer fertilization! Refer to label instructions for fertilizer rates. The reason for using a "palm tree fertilizer" is that it contains magnesium and essential micro nutrients. Typically, sagos only produce one growth flush (crown) per year but may be forced to develop 2 with regular fertilization. (top)
Balanced Fertilization
When certain and various nutrients are used at high concentrations, they can lock up other minor elements. There is a direct relationship between Manganese and Iron. Many people have noticed that their palms get a Manganese deficiency after using a fertilizer high in Iron as the only added micro element. Make sure you fertilize with a balance of these two important micro-nutrients. Adequate sulfates will also be needed to maintain a reasonably decent pH level.
After correcting the nutrient deficiency the next new leaves that are produced should come out looking normal. It takes a few weeks for this to work, so if by chance your sago produced leaves within a few days, then you may need to wait a bit more. Typically a plant in this condition will not flush new leaves very quickly. If you can add some regular palm tree food at the same time (weather conditions permitting) this will produce new leaves much faster. (top)
Pruning
Often folks will cut off all the old leaves to help force out a new flush, but if the plant is not ready to flush soon, this can drain even more energy out of the plant. If one application does not work, I would take the time to check the pH in the soil. Your pH may be so alkaline that you may need to use a product specially made to lower the pH.
Sago Palms are suspected by some to be vulnerable to various fungus disease causing leaf spots, though nutritional deficiencies may be just as likely to blame. (top)
Insects
Scale insects are common on Sago Palms. Inspect the underside of leaves on a regular basis especially if you notice leaf yellowing or a black sooty mold. To control, treat with Insecticidal Oils (weather permitting) or Spinosad® or other pesticide listed for scale. Remember: always treat the underside of the leaves. (top)
Cold Temperatures
Sagos will often be seen draped in blankets or burlap during freezing temperatures. The leaves are quite cold sensitive and may turn brown. As long as the central growing area is not damaged, the plants will likely recover.
The browned leaves will not likely green up again. So, these can be removed once the threat of cold weather is over, usually April. Damaged leaves, even though unsightly, offer some cold protection in the event of another freeze. Injured or cold damaged Sago Palms will often develop side shoots in response to the injury. If these are removed, treat the wound areas with a general fungicide. (top)
Watering
Though Sago Palms are not really drought tolerant plants, they do not do well when the soil is overly wet. Watering too often, or poor drainage can produce symptoms similar to under-watering. Deep infrequent water will produce to healthiest root system. To know how often “infrequent” actually is, you need to know drainage. Use a moisture meter to find out what’s happening to the water that you give your plants. Read Gardening Tip #1012.
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Designing with Sagos
Sago Palms are one of natures most beautiful and showy small trees here in the desert southwest. You can use them to create a tropical oasis in the right location. Surround them with larger trees or shrubs, or add other tropical like Iris, daylilies or even yuccas to bring life to your little portion of our desert.
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