Mangroves are short trees, adapted to the calm, saline conditions found at the edges of bays and estuaries. Their extensive, broom shaped root systems hold soil in place, and can protect entire coastlines from powerful storms. Many coastal areas have lost much of their native mangrove forests to development, exposing shorelines to erosive runoff and wave action. Some of these amazing forests have been successfully restored in Florida, Niger and other tropical places, proving their usefulness for erosion control. You can easily grow mangroves from propagules, which are young sprouted plants produced on adult trees, and use them to control erosion.
Collect mature, rooted propagules, which are at least eight inches long, from healthy trees in early spring. Keep the roots moist with salt or fresh water, and protect them from direct sun.
Fill a 5-gallon bucket half full with the rich, dark soil from underneath the adult mangrove tree with a shovel. Do not allow the soil to dry out. You can substitute other heavy clay soil as long as it is rich with organic material and cohesive enough to be formed into a ball shape when wet.
Cut a piece of cheese cloth about one foot square and place a large handful, or about a cup and a half, of the wet soil in the center. Add a handful of one inch gravel and gently press the rooted portion of the propagule into the soil and rock.
Draw the edges of the cheesecloth together around the propagule to form a ball, which should be roughly the size of a softball. Secure the cheesecloth around the propagule with a cotton string. Wind the string around the base of the propagule and tie it securely.
Choose a sunny location to plant the prepared propagules, where they will be covered by a few inches of salt water at least half of the time. Avoid planting them where they will be exposed to wakes produced by motor boats or strong waves. Space the propagules about two feet apart. Wedge the cheesecloth balls between rocks to keep the propagules upright and secure them in place.