We recommend that the bottom of pot have geo- tech lining (or similar product such as fibre weed mat) to cover the drainage holes. On top then place an even layer of 20mm aggregate stone 4-6cm deep. Once the stone has been placed, geo-tech liner should be placed over the top of the stone. Ensure the liner touches the sides of the pot and goes slightly up the side of the pot to ensure no potting soil mixes with aggregate. Potting mix can then be placed on top of final layer of geo-tech lining. Finally, the plant can be potted into the pot.
Lime in Soil
All potting mix contains lime, and potting mix companies vary the level of lime added to their potting mix to adjust the pH levels. Potting mix with high levels of lime may result in earthen ware pots bleeding lime which will cause a white powder forming on the outside of the pot. This can be prevented by first sealing the inside of the pot with bitumen (product such as Gripset -51) prior to planting up. If lime bleeding occurs in an unseeled pot, wipe off the lime using a dry clean cloth regularly. The lime will eventually bleed out over a period of time. Your planting guides will advise the level of pH required for your plant.
Do not use garden soil as a substitute for potting mix since water may not drain freely, and may cause water retention that can result in structural damage to your pot. Your planting guides will advise you of the best type of soil for your plant.
GRC, Fibreglass pots should not try to be moved when they are full of soil. Pulling or pushing against the sides of a full pot may result in structural damage to the pot. If you need to move a pot that has already been planted, remove the plant and soil first. Re-pot the plant after the empty pot has been moved into its new position.