The challenge of dune planting is to use vegetation that can thrive in an environment which is dry, low in nutrients, based in unstable sands and frequently bathed in salt spray. Even an application of fertilizers and root enhancers cannot guarantee solid performance from all plant materials.

At the Marco Island Beach and Dune Restoration Project about 1 million cubic yards of sand from offshore sources, "borrow areas," was pumped ashore to restore the beach and dune to match that of a naturally created beach and dune system. After delivery of the beach material, a 12-acre dune was sculpted and planted with over a quarter million plants.

The dune planting was designed to provide both quality erosion control and color at the lowest possible price. The Landscape Architect selected Sea Oats and Seagrape as the primary vegetation for low cost dune stabilization. Wild flowers, such as Beach Sunflower, Railroad Vine and Blanket Flower were planted around the dune walkovers to provide colors and highlight the beach access points.

To minimize some of the harsh conditions of the dune environment, the planting effort started in February and finished in April. This timing proved to be ideal for the planting. The weather had become cool and unusually rainy. The cool and wet conditions helped reduce the plant shock which in turn allowed them to adapt quickly to the site. The Sea Oats responded quickly and provided full coverage throughout the project within three months after planting was completed.

On several sections of the dune a root growth enhancer was applied. The intent was to test the new product's potential to stimulate a faster rate of dune vegetation growth as well as to improve on the planting's survival rate. The results of the test proved to be quite favorable. The enhancer was applied by diluting it with water and spraying it on the dune from a water truck. Roughly a one-acre area was sprayed with this product. The plants that were sprayed with the root growth enhancer responded quickly showing new growth throughout the experimental area. The problem however, is that after months of bathing from salt and rain water the root enhancer had dissipated, leaving the soil inhospitable to some of the plant material.

The entire beach spans for 200 feet, and while the project has survived through subsequent storms the vegetation itself is now struggling.

From the '91 project, according to Jerry Neal, Engineering Project Manager for Collier County, the wildflowers used to accent and highlight the sight are not thriving. The Railroad Vine and Blanket Flower are very stressed while the Beach Sunflower and Glaillardia did not survive at all. Of the primary vegetation, Sea Oats and Seagrapes, the Sea Oats survived but are now yellow and they do not intend to plant any more. The Seagrape is thriving and doing very well.

From the test sites using compost, the dormant seeds from the '91 plantings now have sprigs coming up. From this it appears the compost will create a soil mixture in which plants will not only survive but thrive.

So remember to choose your plant material for both their long and short term effectiveness and plan for frequent revitalization of the soil and nutrient base. LASN