Place the plant hanger against the wall and arrange it until you are satisfied with where it is. Use a level to ensure the hanger is plumb and level. Draw a dot inside each screw hole at the base of the hanger using chalk, and then pull the hanger away to check you can see the marks on the concrete cinder blocks.
Check the diameter of the masonry anchors and attach a masonry drill bit of the same diameter to your drill. Drill a hole at each chalk mark that is slightly deeper than the length of the anchors. Wipe away masonry dust from the surface of the wall with a rag after you have finished drilling.
Fit a masonry anchor into each prepared hole. Hammer the anchors in until they are flush with the surrounding wall. Remove the masonry bit from the drill and attach a screw bit appropriate for the screws you are using.
Place the plant hanger against the wall and line up the screw holes with the anchors. Drill a screw into each anchor. Tug down gently on the hanger to ensure it is securely affixed, and then hang your plant.