Bit difficult if your soil is very rich, but otherwise, just choose a spot where it gets sun and where you've not added any fertilizer. I haven't got particularly poor soil, but they pop up every year and ramble all over, flowering away merrily, despite two applications of Growmore in early spring and early summer.

See you have a new avatar, if that's the name for your picture - intriguing. Thanks Bamboo, but it doesn't work for me. I've tried them all over the place but can't keep them.

Odd - maybe your soil is just really fertile, lucky you. As for the avatar, decided it was time for a change...

Do you remove the flowers before they set seed, but reallly
I think they have a short season....especially with the blackfly!

Well I don't ever deadhead, Pamg - but they are late to come into flower most years, probably July, but they do go on to the first frosts, I find.

They flower, get covered in blackfly.....then pop their clogs. :0)

Maybe it depends whether you care or not - I shoved in Alaska mixed and Empress of India about 5 years ago - haven't planted any since, and they pop up all over. I never even look at them other than to pull out ones where there's already too much planting. Must be all the inattention and lack of care they thrive on, lol.
I do have heavyish soil though, and they're not in full sun - any year I mean, not just this year, they get half a day if there's any sun to be had in the mornings, maybe that makes a difference.

Mine are in full sun and heavy soil and flower like mad all summer. Like Bamboo I never need new seed, and have to pull lots out in the spring. Some plants like some places and not others and the trick really is to go for plants that are happy in your particular place. You might try growing some in containers in last year's compost and see if they do better there.

Now mimulus do better here, I,ve some in a trough that set seed last year and are happily flowering

Thanks to all. Have them in 2 containers this year. One was planted up in fresh compost; one came from seed in last year's compost and has only just flowered. The ones in the fresh compost are really struggling but it will be interesting to see if the one in the other pot does better.I only left it in there as that is where it had grown, as I thought using old compost was supposed to be risky in terms of pests, diseases etc. Nasturtiums aside, nothing is doing that well in containers with this year's weather.

That's one exception I've experienced - nasturtiums never seemed to like being in pots, even though I used poor compost. I'd expect the one in the reused compost to do better than the one in fresh, TuesdayB, but it'll be interesting to see.

Yes, Bamboo; they are doing much better in the old compost. Hooray! So they prefer to be in the ground, tho'? Will try that again too. Thank you all.

Jolly good...

Garlic, planted next to the nasties, might go some way to repel the blackfly, Tuesdaybear.
That's what I've been told so am going to try it.
Other than that, deadheading.
Worth a try, maybe.

Definitely worth a try. Thank you.

Welcome. :-)