Retaining Block Tree Ring
Landscape marking paint
1/8th inch hardboard
Catalina retaining wall blocks
Concrete block adhesive
Tired of trying to grow grass under your pine trees? Installing a landscape feature is a great way to avoid the headaches of patchy grass that's difficult to mow. A concrete tree ring is a simple landscaping solution that will look great for years to come with little maintenance. The building process is easy and can be completed in a weekend.
There are two main reasons to use a concrete slab as a tree ring. First, a concrete slab gives you a nice flat surface that is more durable than a sand or gravel base. Second, a concrete slab leaves a nice smooth edge to mow over so you will never need to use a string trimmer.
Start by marking a circle around the tree. Use landscape marking paint so the line can be seen clearly. Following your line, dig a trench three inches deep by twelve inches wide. Cut your hardboard into long, three-inch wide strips. Then, using the hardboard strips, create the forms for the concrete. Stake the form into position with the steel stakes every two to three feet. Check the form for level in multiple areas and adjust if necessary.
Mix the concrete according to the manufacturer's directions and then shovel the concrete carefully into the trench. Gently tap the form with a hammer to eliminate air bubbles. Trowel to a smooth surface. Once the concrete is set, the forms can be removed.
For this project, Catalina retaining wall blocks are used as edgers, but there are many other materials options available. Do a dry run of your block layout. Then, hold each edger permanently in place with block adhesive. Catalina blocks feature a tumbled and weathered look and are available in three sizes so you can either use all the same size, or mix and match sizes for a custom look. It may be necessary to cut some blocks so they fit into place. A concrete block splitter, available at your nearest Menards®, will make a clean, precise cut while maintaining the rough, natural look of the Catalina block.
Next, place landscape fabric on the ground between the ring and the tree trunk. This will prevent weeds from growing but still allow moisture to get to the tree roots. Finally, spread a layer of wood mulch over the fabric. You can also fill with top soil and create a plant bed.
For building or material advice or help estimating your project, visit your local Menards® and try out the free in-store Design-It Center®, which allows you to design the project you envision and then provides an exact list of the materials and quantities you will need.