Crocks in pots – do they make a difference?
I’m not a fan of unnecessary work, and faffing about
with drainage layers of gravel or crocks at the base of containers is a job I culled long ago. I’m not saying you should throw away all your crocks – just one loosely covering the drainage hole is helpful simply to stop loose compost coming out while the planting gets established, and it gives you something to push against when you eventually empty the pot.
But drainage layers? Don’t bother! I’ve found that as long as a container has at least one reasonable drainage hole, a layer of drainage material at the base makes no discernible difference to the health of the plants in any season. It is much more important to put your plants in a position that suits them, in a pot that is big enough but not so huge that the roots can’t colonise the whole thing in a few months, and to use decent compost. Slugs love to live between crocks and will come out at night for a convenient meal.
When it’s time to empty the pot, falling crocks rip the entangled roots of your plants and make a horrible mess. The compost and roots often eventually fill the spaces between the crocks anyway, making them redundant. Studies have confirmed that water is reluctant to move from a medium with small spaces (compost) to one with large spaces (crocks), so you may even end up with a perched water table – a layer of soggy compost just above your layer of crocks and therefore closer to the roots of your plants.
It’s much better to use good compost throughout the container. Choose a peat-free compost that feels crumbly and remember when you plant your pots not to squash the compost down hard, as you’ll ruin that nice spongy structure and your drainage.
Yes, I’m a crock user. You might say that it is because
I was brought up to use crocks in the bottom of pots and that it’s a habit I just can’t break, but no. Firstly, when I was a child we grew almost everything in open ground and bagged compost was simply too expensive; secondly, there are pl
