After seeing Wuvie's instructable:https://www.instructables.com/id/Easy-to-make-concrete-bowls-and-planters/, I knew I had to do this. So, having all the available tools and materials on hand, I proceeded to make a functional planter using a plastic bowl and a bowling ball as molds. Having made several instructables that utilize concrete, I will refer you to those sites:https://www.instructables.com/id/Make-Unique-Planters-With-Concrete/, for example and, of course Wuvie's excellent instructable, listed above.

Step 1: Gather Materials and Tools

See above listed instructables for complete material lists, and tools needed to complete this project. I have shown the specific plastic bowl and bowling ball used.

Step 2: Provide for Drainage

As a gardener, I know that you must absolutely provide for drainage holes in any enclosed planter, else the plant roots will rot in the water that stagnates in the bottom of the planter. In order to provide that drainage in my planter, I decided to use a piece of PVC pipe cut to about 2 inches. This will be placed in the bottom of the mold and support the bowling ball, and allow for 2 inch sides, provide the necessary drainage and make it unnecessary to drill the concrete later on.

Step 3: Mix Concrete and Pour Into Mold

After coating both the bowling ball and the plastic bowl with a very light coat of vegetable oil, or a Pam like spray, the mold is ready to be filled. Mix concrete according to instructions and fill mold. I used 8 soup cans full of concrete to complete this pour.

Step 4: Decorate Concrete at This Point

I decided to decorate the lip of my bowl with glass beads available at any craft store. We had some on hand, so decided to use them up. You can wait up to 45 minutes or so to do this step, but I went ahead and completed it as soon as I had poured the concrete. A simple design was used, but tried to place them in a manner pleasing to the eye.

Step 5: Let Set Overnight Before Removing Bowling Ball

The concrete must set up to a point where removing the ball will not break the sides of the mold. After at least 24 hours, or longer, simply lift the ball out of the mold.

Step 6: Let Bowl Cure for a Week With Water in It

I found that leaving the ball in the plastic bowl mold, I could fill the bowl with water, and that would effectively allow for proper curing. I am not sure of the one week time, but decided to go that route since there would be no harm in waiting.

Step 7: After One Week, Remove Plastic Bowl

I had a little trepidation, but concrete never ceases to amaze me! After removing the plastic bowl, the project was essentially complete. Now to plant the bowl and place it in the garden.

Step 8: Select Plants and Add to Planter

I used a packaged cactus mix as I wanted the best soil type for the succulents to be added. Placing a screen over the hole in the planter, the soil and plants are added as in standard practice for potting plants.