Help pls: lavender colour flower that blooms into September?

[amoreoamicizia]

I'm just trying to finish planting some pots that I'm doing as a "thank you" to someone for their help. Where there are some pink cosmos I'd like to soften the look with something lavender coloured that will be a bit subtle and softening vs. the cosmos, a bit cottage garden-y, but also- and this is the challenge- keep flowering into September and not just finish in a couple of weeks.

Verbena has been suggested but although it keeps blooming, the purple is a bit strong for what I want. I'd like more of a lavender colour because of what's already there. I've also seen some nice salvias but I think they'll finish soon. Maybe nepeta, but if so which one and does that work in pots? 🤔

Does anyone have any suggestions? I've added a photo for inspiration. Thanks 😊

Michaelmas daisies?

Here's some possibles.

Geranium Rozanne ('Gerwat'PBR)|cranesbill [Rozanne]/RHS Gardening

Convolvulus sabatius|blue rock bindweed/RHS Gardening

Nemesia denticulata|toothed nemesia/RHS Gardening

Two posters beat me to it!

You may have other/better suggestions? I'm sure there are lots of possibilities? I only stopped at 3 because I might come back to it later with new ideas. 🌸

Thanks 😊
It's a good suggestion but there are already daisies there.

The geranium Roseanne is hugely popular, I think, but slightly too bright for what I need. It's definitely on my list for my own garden, though! I'm looking more for something subtle to offset the rather bright pink of the cosmos.

I think ideally it would be something with stems, like lavender/salvia etc. to provide a backdrop for the cosmos.

Can anyone identify the plant in the photo? Google image search isn't giving me anything.

It's a good suggestion but there are already daisies there. That's the problem with late summer/autumn - it seems so many of the late flowering plants are Asteraceae.

Not a good enough photo, I'm afraid. We can't see flower shape or be clear which leaves belong to the plant.

What about something like an erysimum Bowles mauve? Evergreen and it varies from more purple to a pinky colour.

Possibly verbena bonariensis

I thought it resembles verbena bonariensis, too, but the colour seems paler 🤔

Difficult from the photo, but could it be a Thalictrum. More thoughts on light lavender, russian sage,nepeta. The erysium bowles mauve is a spring wall flower.

My experience of the Bowles Mauve is that it flowers all year around - mine are currently going strong in the garden and I've had flowers throughout the winter too.

If those oval leaves belong to it, it’s not Thalictrum.

My Thalictrum finished weeks ago

How about some variety of aster? There are some nice light purple ones, and they can be quite late-flowering.

Caryopteris

Japanese Anemones - September Charm, though mine are out now.

I find Salvias go on for ages. There are some nice paler blue ones.

I can't see what those flowers are in the photo, it is hard when they aren't in focus.

Plant in photo looks a bit like Marjoram, it easily runs to flowere. I leave it as it’s very pretty and the insects like it.