What can I put in the bottom of plant pots to assist drainage?

[Cornfurnno]

I had previously dug up stones from the garden but discovered that they actually help with its own drainage so I should not be digging for them? I thought I could use polystyrene from packaging, but then when I emptied the pots recently they just seem more like ‘landfill’ than drainage.

Traditionally we'd just put shards from old pots over the hole in the bottom. For more elaborate drainage, maybe get those little clay balls used for hydroculture?

Horticultural grit?

When you say drainage, what are you trying to achieve?

For fast-growing greenhouse plants like tomatoes I just put a piece of newspaper in the bottom to stop the compost draining out until the roots fill the space.

For permanent large planters I've used old bricks and large bits of broken pots in the bottom and then gravel.

For smaller semi-permanent planters I usually use smaller bits of broken pot, or I do the newspaper thing.

Yamadori I’m trying to help the bottom not end up like a cesspit.
I always assumed you made sure the one hole (or if lucky more holes) remain clear flowing so that compost doesn’t just drain out. However I thought that if you don’t have enough broken pots, or in my case stones, at the bottom then if you have periods of prolonged rainfall like in the winter or with snow melting or with overwatering a pot, that the base of the pot/compost could end up very wet and yuck. Am I wrong?

Good article here

https://deepgreenpermaculture.com/2020/10/06/how-to-improve-drainage-in-plant-pots-the-proper-way-to-do-it/?amp=1

Not seen clay balls grumpypanda but had wondered about horticultural grit just thought it was probably expensive for decorative purposes nevillesleftnadger

sinisterknitter what’s the newspaper thing? I had wondered about egg boxes but thought they’d just become a soggy messy pulp.

Well dammit, I wish I'd read that article this morning, rather than AFTER I've just potted up loads of plants. I've used clay pebbles in the bottom of the pots - I just hope the plants survive!

I've saved that article for future reference.

You're not entirely wrong - exactly, but you're not right either. All a layer of fast-draining crocks or gravel does is to raise the water table into the compost above it. So the roots sit in a damp layer anyway. I've been to a talk by a horticulturalist, who actually demonstrated the effect, because we didn't believe him to start with either. If you want to just prevent compost from falling out of the bottom of the pot, then use some kind of mesh (like greenhouse shading or those bags you get with citrus fruit) to cover the holes. The only useful reason to use crocks or stones at the bottom is to increase the weight, so the pot is less likely to blow over in windy weather.

For plants that like free-draining soil, it is better to incorporate hydroleca (fired clay balls), pumice or lava within the compost itself. All of those have air pockets in them, which helps with free drainage. Gravel doesn't work.

Oh lol - I just read that article after I posted my response above, and it appears that I wasn't talking rubbish, and I'm not as stupid as I look after all 😂

😂

I do put stuff in the bottom of large containers (plastic bottles, polystyrene packing bits) but only cos I'm too tight to pay for all that compost etc for annual flowers that are often shallow rooted.

I used to use garden compost for the same purpose.

Then during Covid when garden centres were closed, I used garden compost for the whole thing, and haven’t gone back since