Gardeners don’t like throwing things away.
If you need evidence look in your garden shed or, indeed, at the plants in your garden. And, if you can bring yourself to dig up a plant you have subconsciously loathed for years what do you do with the corpse?
You are unlikely to put it in the green recycling or on your compost heap. It’ll be passed to a neighbour so you can shudder at its sight from the back bedroom window or pot-up bits and take them along to the annual gardening club sale so that some other poor bugger can grow it. I reckon this reluctance is the reason why shards of broken clay pots end up in the bottom of other large pots.
“Wrong!” (I hear you say.) “I was taught to put them at the bottom of the pot. It helps drainage and stops the compost falling through.” But putting crocks in the pot hinders drainage. The last saturating water after initial excess has drained through is expelled by capillary suck from whatever surface the pot is standing on. If you break the continuity between the compost and the ground with air spaces produced by the crocks this can’t happen.
It’s a simple experiment you can get students to carry out with measurement and controls. Pots with crocks remain wetter for longer. Pot feet (a wonderful marketing opportunity) have a similar effect. On the other hand, maybe wetter is what we all want in summer when getting water into pots is the chief problem.
As for the compost falling through. If the holes are very large like the fist-sized drainage holes in Whichford pots I put an old piece of cloth across the hole. With smaller holes the compost doesn’t really fall through at all.
Second thoughts. Some people put broken polystyrene at the bottom – which can only be because they are trying to save on compost so maybe it’s about saving money.
I put my pot shards on the back lane to help fill the potholes. I recycle yoghurt pots conventionally.
