Make a concrete tabletop planter for your veggies and you will have a kitchen garden feature to last a lifetime.
What you will Need
• 50 mm polystyrene cut slightly larger than the tabletop you want to make
• Ceiling cornice
• PPC cement
• Fine river sand
• 13 mm building stone
• Wood screws
• Wood planks the same width as your cornice
• Granular paint
• A base for the table (a rustic crate, log off-cuts or bricks)
Pencil, tape measure, straight edge, jigsaw, bucket, trowel, hand saw, screwdriver, sponge or cloth, rubber mallet, hammer drill and drill bit, paint brush
1. We will begin by making two moulds from ceiling cornice, which we will later use as forms for our concrete planter table. Use a piece of shutter board as your work surface. In the middle of the polystyrene, measure out a rectangular outline of the tabletop you are making – our tabletop is 990 mm x 600 mm. Using a jigsaw, carefully cut out the rectangle to form a frame.
2. Cut a strip of polystyrene (200 x 600 mm) from the off-cut, which will later be sunk into the mould. Don’t worry about exact positioning at this stage.
3. Cut the cornice into lengths to match the inside of your cut-out space, using a mitre saw for 45° cuts. The cornice pattern must face inwards to create the table’s pattern. Place these cornice lengths inside your polystyrene frame and screw them together to form a rectangular box. Be precise – this is going to be the decorative edge of your table.
4. To create a mould for the planter sides, cut and screw together the wood planks to fit around the inner piece of polystyrene.
5. Cut (with a mitre saw set at 45°) and screw together a cornice frame that is larger than the wooden frame, so that it will create concrete walls of at least 2 cm thick. Face the cornice pattern inwards. For added support of the cornice walls, you can screw four strips of wood to the shutter board work surface, to hold it in place when the concrete is poured. Remove the polystyrene inside the wooden frame and keep for use with your tabletop mould. You now have two moulds: one for the larger tabletop, and one to form the walls of the planter.
6. Mix together 2 parts cement, 2 parts fine river sand and 1 part 13 mm building stone and add enough water to create a fairly fluid consistency that is pour-able but not too runny.
7. Add some of the concrete mix to the tabletop mould, filling it to ±50 mm below the top edge of cornice. Place the 200 x 600 mm polystyrene rectangle in the middle of the mould and weigh it down with a brick. This is to create a depression in the tabletop for added planter depth. Add concrete mix around the polystyrene rectangle until it is flush with the top of the rectangle and the cornice mould. Bang the mould with a mallet to vibrate out the bubbles and ensure a smooth finish. Wipe off any mess. Keep moist or covered for three days.
8. Using the same concrete mix, fill in the planter mould to create the planter’s walls. Tap the sides with the rubber mallet to get rid of air pockets and wipe any spillage off the top and edges for a smooth finish. Keep moist or covered for three days to cure.
9. When the concrete is completely light grey and therefore dry, unveil the tabletop by unscrewing and removing the moulding, and remove the polystyrene from the centre – you will have to dig it out. To remove the planter mould, unscrew the wooden supports from your work surface, unscrew the cornice corners and pop the cornice off. Push the wooden box out of the centre of the concrete planter.
10. Mix up a slurry of dry cement powder and water. Turn the planter upside down and spread slurry on the edge to be stuck to the tabletop. Ensure that the pattern of the tabletop and the planter are facing the same way up. Place this edge onto the tabletop, surrounding the depression made by the smaller piece of polystyrene and clean up any spills of slurry. Keep moist or covered for three days to cure.
11. Drill holes in the base area of the planter for drainage. Sand any rough bits of the tabletop and planter, then paint it with a granular paint and allow to dry. Place your planter in the garden or on your patio, using a rustic crate, some logs or a small bagwashed brick plinth as a base.