Why does Monty Don do this?

[bigbeautifulmonster]

On Gardeners' World last night, when potting up his chillies into larger pots, Monty advised that we fill the larger pot with some compost, sit the plant/rootball still in its pot into the larger pot, fill compost around it, take old pot out and voila(!) there's a perfectly shaped hole to then put the new rootball in.

He's suggested this in the past too and I've always wondered why.

What's wrong with just putting the new rootball into the new composted pot and just tapping new compost around it?

Am I missing something?

I saw this too, DH and I couldn’t really work it it but I wondered if it’s less likely to form air pockets?

It's to ensure you fill the space around the rootball properly, and keep it level. When you take the smaller pot out, you can see if you've properly filled the surrounding area. Then you put the rootball in, and it's on a level surface already and it's easier to push a little more compost round the rootball.

Because some plants have quite tender roots so it can help reduce the impact of potting on.

@Yarnasaurus ok yes that makes sense. Though I did it today and the moulded compost would just kind of collapse in anyway. Especially as the upgraded pot was only marginally larger, going by what he was doing yesterday.

Air pockets I thought would just be minimised when watered. Though roots are better with some oxygen in the soil, no?

Though roots are better with some oxygen in the soil, no? Soil structure is on a very small scale, commensurate with the tiny invertebrates that contribute to its health. An air pocket you can see is like coming out in the open air to them.

I also find it quicker this way as I does have to be so careful with roots.

I find it very satisfying to just plonk it in the bigger pot with the hole already in place