Photo Credit: Heidi Long
Dendritic patterns, such as the ones shown here, occur naturally in rocks such as limestone as iron- and manganese-rich water flows through the layers and deposits dendrite crystals. These crystals then branch out into tree-like shapes, essentially replicating a fossil.
You can create a similar look on concrete materials through the use of natural foliage and iron sulfate (also known as copperas and available on Amazon
and select garden centers), which reacts with the surface of concrete to produce a reddish-brown color. Follow the steps below, and let the creativity begin.
1. Prepare Your Surface
Thoroughly scrub the non-sealed concrete surface with soap and water, and rinse with clean water. You may also wish to sand away any imperfections, such as previous stains left by other materials.
2. Mix the Stain
Mix the iron sulfate with warm water at a 1:1 ratio.* (Note: Do not mix until ready to apply.)
3. Apply the Stain
Use a paintbrush or sprayer to apply the stain over the surface of the concrete object.
4. Place Your Foliage
While wet, set the intended foliage on top of the stain to create imprints. For a darker effect, dip the foliage in a stain prior to setting it on the concrete.
5. Finish Up
Let the stain continue to dry for approximately eight hours. Remove the foliage.
*As with all stain and painting jobs, test the solution in an inconspicuous area of the object being stained. If the color is too intense, remix the solution using a smaller amount of iron sulfate. Be careful not to overly dilute the solution, however, or it will not produce the intended chemical reaction.