Monday, August 29, 2011

Killer Salt Water

If you're thinking wind and flooding are the only threats to your landscape by a big coastal storm such as Hurricane (then Tropical Storm) Erin, you're wrong.

                                                                                 Fema News Photo
Coastal storms can present property owners with a third threat as they send surges of sea water onto coastal landscapes, leaving behind sea salt on foliage (from spray) and in the soil. And while sea salt goes great on popcorn and corn chips, trees and shrubs do not like it. Most, in fact, would rather die than tolerate salt.

When Hurricane Katrina collapsed levees in New Orleans, Louisiana in 2005, vast areas were inundated with salt water. The salt, as much if not more than the water itself, wiped out seventy-five percent of New Orleans's urban forest, including the grand old live oaks and sweet-scented magnolias for which the city is famous.

So what does salt do to a plant? Think of the reason you gargle salt water when you have a sore throat: it  draws out inflammation. Well, salt has a similar (though wholly negative) influence on plants: instead of drawing out inflammation, it draws out moisture. It also burns foliage.

If salt spray can be hosed off foliage soon enough, damage can be minimized. On the other hand, if the soil itself has been saturated by salt water, the only remedy is a thorough flushing (after it has had time to dry out), either with irrigation or as a result of heavy rains. This process can take weeks or months. Only then is the soil suitable for replanting.

If your landscape's anchor plants succumb to a high-salt diet, you can help save yourself from a repeat performance in the future by opting for replacement species that are relatively salt-tolerant. After all, the storm that killed your plants won't be the last.

And speaking of salt-tolerant plants: what are the favorites in your locale?

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