Many years ago South Florida was a palm paradise, with a tall, dense canopy of palms swaying in the prevailing southeasterly winds. The legendary tales of the thousands upon thousands of tall coconut palms in the lower coastal areas gave rise to visions of paradises lost from the Pacific. Innumerable business and real estate and restaurant and hotel names sprang from the palm's namesake. The brilliant yellow coconuts, set against a rich canopy of 20 foot emerald fronds, set atop trunks as tall as 70 feet, made Palm Beach, Fort Lauderdale, Miami and nearby cities a grand attraction.
Then, in the late 1960s, something awful happened. A disease called Lethal Yellowing started in the Florida Keys, which spread and raged through the lower part of the state like a slow forest fire, killing thousands upon thousands of coconuts and other palms. The disease is still here, but there are rather few coconuts for it to infect compared to the 1960s or earlier. There is now a certain nervousness about planting coconuts, even the "disease resistant" ones. This is a textbook case of a pest destroying a monoculture, wherein far too many of a single type of plants was grown in a defined area. This was the case with Dutch Elm Disease destroying its primary host, likewise with whiteflies destroying Poinsettias, and so on. The moral of this story is that planting large numbers of the same thing is asking for trouble, and usually trouble arrives sooner than you expect.
How can we alleviate or prevent the problem ? The answers seem simple, but have deeper difficulties embedded in them. Let's look at some of the "clear" answers, and see why they have not been employed as best they could be.
The obvious answer is to plant trees which are resistant to diseases and pests. This is easier said than done, since many commercial nurseries have large inventories of "old classic" mature palms they need to sell before they can re-stock with resistant species. Another reason that disease-resistant plants are not grown as commonly as they could alludes to the lower supply of disease-resistant coconuts. These resistant species often have higher price tags and growers are already looking at increased costs for almost everything as it is, much less having to pay for improved plant stock that may not sell.
Many growers state that native plant species are automatically disease-resistant, to which I say that the plants from your local area, soil type, and weather are usually durable. On the other hand, though, the wrong plant in the wrong exposure can be fairly weak and disease prone. There is little exact science that would allow growers to state that a chosen variety of palm is , for instance, 90% resistant to Lethal Yellowing. It becomes a game of statistics, that fewer coconuts will die if you plant lots of Malayan Golden Dwarf coconuts than if you plant Atlantic Tall coconuts. A good case could be made for planting alternative species that are disease-resistant, but many landscape architects will specify coconuts in a design and many homeowners or businesses will ask for coconuts. There are numerous palms that bear a resemblance to coconuts that have a higher resistance to Lethal Yellowing, but the supply is shorter, and the prices are usually higher. For large commercial installations, coconuts can be acquired in large numbers, exactly according to specifications, whereas an allied species like Archontophoenix or Beccariophoenix may not be so easy to find.
With growers looking at tough economic times, many of them wish to sell what they have, and may not be interested to re-stock the "improved" varieties. Landscape architects may not be as current as they could be in knowing about new varieties, or even aware that coconuts are still risky for some installations such as pool islands in a courtyard. The supply of newer, more disease-resistant varieties like Red Spicata , Red Malayan and Fiji Dwarf is remarkably small, and the prices are higher than the old fashioned, fast-growing Panama Tall or Maypan. The look of the newer varieties is different, too, than the grand and majestic Panama Tall or Jamaica Tall, with their giant coconuts and 30 foot diameter crowns. The Malayan varieties also need more water and fertilizer in our coral soils than do the older tall varieties. There are choices to be made:
- whether we need to re-assess our devotion to coconuts by replanting with other palms,
- whether we should choose disease resistant varieties that need more care and cost more than older varieties,
- or skip the use of palms altogether.
|'Red Spicata' Coconut, |
moderately disease resistant