Best zone 2-3ish London garden centre?

[WhiteSandyBeach]

A friend and I are planning to meet up for an afternoon and have a wander around a garden centre in London. We’re on opposite sides of the city though, one southeast and one northwest. Neither of us drive.
Does anyone know of a lovely garden centre that we could both get to on public transport? A great tea room would swing it!
Planning to buy seeds, small plants, and maybe have a scone or two.

Battersea Flower Station is highly spoken of but has no tea room (several good cafes very nearby though).

An alternative but fun suggestion would be Columbia Road flower market on a Sunday morning. Busy, but a lovely day out.

Clifton Nurseries is very close to Warwick Avenue tube. It's not massive but you can potter round it and it has a very nice cafe.

Oh nice - like the sound of both Clifton and Battersea. Thank you!

And not that the Columbia Rd suggestion isn’t a great one! It is, and I know it very well. Just after more of a pot-of-tea than a flat white sort of afternoon, if you see what I mean.

Not quite what you’re after but Kew Gardens should be accessible for you both, has a tea room, and a shop that sells both plants and seeds!

Chelsea physic garden

Petersham nurseries in Richmond? There’s a bus from Richmond Station, or it’s a nice walk along the river.

Clifton is really nice. I also like Rassells on earls court road, no tea room but you're really near high st ken with many options!