Fine Tuned Palm Cultivation - Part One

Another thought provoking and practical article from Don, this time covering fungus and fencing!
Don Tollefson, 599 California Avenue, Venice, California 90291, USA
Chamaerops No.30 Spring 1998

Over the years you gradually learn what does and doesn’t work for palm gardening. As time quickly passes you realise that by the time you’re old, you could do it right if you were just a little younger. Part one of Fine Tuned Palm Cultivation covers fungus attack and control, fertilisation and the overwhelming benefit of a solid fence (for wind protection). These tips are designed to help you move faster than time. After all, moving faster than time is the real secret to growing palms.

The Fungus Among Us: Fungus is the number one killer of palms. Most often, fungus gets a foothold in the winter. Fungus is invasive and when the palms are fending off the evils of cold and wind, a nick or cut in the plant tissue enables its entry. It is always present in the air, but it can only attack weak or otherwise setback palms. Fungus exhibits its presence in two ways (or perhaps there are two types of fungus). In either event it can attack the emergent bud or it can attack the stem. Thus the monsters, “bud fungus” and “stem fungus” (aka bud rot and stem rot). Bud fungus is much more common. Stem fungus is much more serious. With bud fungus, the bud will emerge, die and can easily be pulled out from the surrounding sheath. With stem fungus, the fronds die prematurely from the oldest upward until only the spike remains. Splits may occur on the trunk about 6" to 10" above the ground accompanied by open wounds. Then, inexplicably, the palm falls to the ground with a rotted base a few inches above the soil. Ironically, the spike and perhaps one or two of the remaining, newest fronds appear fabulously lush. Thus provided the misleading impression of pending recovery. The treatment for both conditions is fungicide (fungicide, pronounced with a jay or soft Gee). Predictably, a bud fungicide is recommended for bud fungus and a stem fungicide is recommended for stem fungus. You knew that! Some growers recommend a cocktail mixture of both. It is wiser to apply the specific fungicide for the specific fungus problem.

Spraying the bud is the treatment for bud fungus while drenching the soil and the trunk of the palm is the treatment for stem fungus. Repeated weakly treatments generally result in recovery. Successful stem fungus treatment requires many more applications over a longer duration than bud fungus treatment. If stem fungus is advanced, the palm will forever bear the scars of the infection. Typically, the victims of bud rot are first year plant-outs. If the bud pulls out, but the remaining fronds are healthy, most often a properly treated palm will recover. Older, established palms are the ones that most often fall victim to stem fungus. Particularly in the winter because that’s when stem fungus becomes most active. Remember, it requires a cut or sore for stem fungus to enter a palm. Most of these opportunities are created by the overly enthusiastic palm enthusiast This oxymoronic individual, impatient to see an old, unattractive frond fall off, cuts a frond at a location on the petiole which is still green. Growers must cut only the part of the petiole that is dead and completely brown to avoid fungus entry. Then patiently allow the remaining sheath to fall off by itself a few weeks later. Therein lies the second error. Pulling off a dying sheath before it is completely dead and ready for removal. Everyone loves to remove an old frond for the delight of exposing a fresh, new leaf scar. This is always accompanied with the overwhelming sensation that their palm just grew six inches in a few seconds. But if the sheath is not completely dead the leaf scar is not completely sealed at the location of petiole attachment. Removing it prematurely results in plant tissue damage at this point. This provides the perfect opportunity for fungus attack. Don’t be your palms' own worst nightmare.

Stare and spare: By far the best cure for fungus is prevention. There is a simple method of decreasing the incidence of fungus attacks. I call it “stare and spare.”! As you periodically tour your garden and observe your palms (stare) make it a policy to carry a spray bottle along with you. As you observe each palm, spray it’s emergent bud with a solution of fungicide (and spare). Also, spray any noticeable cuts or open wounds on the bases of the older palms. Make an effort to visually inspect the entire surround of the trunks. Treatment about once per week is ideal. Adjust the spray to shoot a bead of solution like a squirt gun. It’s an effortless, mindless regimen that will cut your fungus problems by 95%. In particular, it will boost your first year palm’s survival rate substantially.

Fertilizing: Traditionally, slow release fertilisers have been recommended almost exclusively for palm cultivation. Fast, easy to apply and inexpensive, what could possibly be better? Indeed, most fertiliser discussion has been confined to the ratio of the nutrients in slow release and the duration of their release period. But recently, many accomplished growers have concluded that liquid fertilisers are superior. Being exposed to countless miracle-grow T.V. commercials, everyone knows the theory. Liquid fertilisers provide fertiliser to the leaves as well as to the roots. Additionally, upon reading the label of a container of Miracle Grow fertiliser, it says, “Many expert growers recommend continuous application of Miracle Grow in dilute solution each time they water”.

Quite an outstanding tip. And continuous fertilising makes continuous sense. The plants’ roots and leaves receive nutrients from a dilute solution of liquid fertiliser each and every time they are watered. This provides the opportunity to supply palms with the maximum amount of fertiliser possible to enable maximum growth and appearance. There is no down time. No period when you fall behind. How well is your current fertilising regimen working? Examine the leaves of your palms. They should be a deep, lustrous, lush green. If they aren’t, they probably aren’t receiving adequate amounts of fertiliser. As a practical matter, the palms of very few growers completely exhibit the look of adequate fertilisation. Invariably, one frond or another on any particular palm will reveal that the grower dropped a little behind on the fertilising program at some point. And behold the consequences if a grower applies too much fertiliser trying to play “catch up.” Fertiliser bum! And no one wants that. Continuous liquid fertilising enables the grower to duplicate the palm in habitat where it receives a constant supply of dilute nutrients from the continuous fall of leaf litter and other organic matter.

It is critical to deliver the solution to the palms in the proper proportion. Miracle Grow is a rich, dark blue in its chemical form. When introduced to water it turns the water blue as well. To ensure that you’re applying fertiliser in the correct proportion, carry along a white, 20 oz., styrofoam, throwaway coffee cup. Pour a little of the solution into the cup as you water your palms. With an inch or so of water in the bottom of the cup you should be able to detect an ever-so faint, bluish hue. If you detect a darker hue, your mix is probably too strong. Upon adding more water into the cup, the water will appear a slightly darker blue with the increased depth of the water. A full cup of water with fertiliser solution should appear distinctly blue. More fertiliser than that can be risky with continuous application. Remember, fertiliser burn can result from liquid fertiliser just as with pellet fertiliser. Be sure to turn off the water at the spigot if you use a hose end shutoff so that water is not backfed into your solution. If your palms were under fertilized they will green up after only three or four waterings. This greening will continue at a slower pace for three or four weeks after which time the palms peak. Once the palms peak, the secret is to keep them at their peak “with continuous fertilising, using a dilute solution,” Just like it says many experts do on the Miracle Grow container label!

The Almighty Fence: Often there are reports of various microclimates in particular areas that result in exceptional palm gardens. Inexperienced palm enthusiasts visit such gardens and concede that the growers really do have some unfair microclimatic advantage. But sage growers know that these exceptional gardens are generally just the result of the presence of a solid fence. Why is such a fence so beneficial. Because it protects the palms from wind. Particularly the brunt of direct, cold, wet and excessive wind. Next to cold, wind is the most restrictive factor in successful palm cultivation. Consider a palm in habitat. Anyone who has been in the jungle will report that even though the wind may be screeching violently overhead, it remains relatively calm on the jungle floor. Consequently, palms are not biologically adapted nor suited to tolerate much wind. And if that wind is cold, wet, and intense, the problems increase exponentially. Enter the concept of wind chill. Many botanists insist that there is no such thing. They said it, I didn’t. A strong, cold, wet wind can easily produce the damaging effect of a temperature 10 to 20 degrees colder. Now ask yourself, is that good or bad for your palm collection?

When you visit the garden of an enthusiast who is growing palms that no one else in that area has ever before grown, invariably, the yard will include a solid fence. If you want the same advantage, either erect a solid fence or plant vegetative growth around your palm growing areas. It is similar to the advantage that a grower receives by growing plants in an open topped cold frame. Even though the palms receive absolutely no additional heat they still perform far better than their littermates outdoors. Bottom line.. decrease the wind, increase the success.
Fine Tuning Palm Cultivation Tips - Part Two Will Cover the Shade House, Over-ready Versus Under-ready Palms, Inching the Palms from Shade into Full Sun and Air Circulation for Passive Solar Greenhouses Provided by a Trombe Wall.

Don Tollefson publishes <The Diamond Lane Guide to Growing Palms> a 202 page instruction manual on palm cultivation from “The Tropics to Sitka, Alaska.” It can be obtained by sending $29.95 plus $2.95 for shipping and handling to:- 599 California Avenue, Venice, California 90291, USA.