they are fast growing ruderal plants so they do love nutrients and can use them,

do you have any other plants growing nearby which look very well fed as well?

and near the margin/ edge the bits kind of sewll or bend between the "nerves" of the leaves (intercostal ) that is usually a sign of very much or too much nutrients

my guess is that it is a very rich spot

Have you tried althea cannabina Rob? If not, I can send you some seeds if you fancy it.

I love the mallows too - currently having a little pash on the sphaeralceas.

That's actually a part of the yard I've never amended. And the people that lived here before me didn't have a garden there. I don't understand why it would be so rich, but there you go.

6 or 8 feet from it though, is where I grow tomatoes. Again, without amendment? I just don't do that very often... And they will grow as tall as the pergola, 12 ft.

I will have to check out sphaeralceas 😊

Ah, I just looked up 'French Hollyhock'. I am amending my comment 'I love the mallows too' and adding 'apart from malva sylvestris which is a terrifying weed with roots which reach Australia'.

At least once a month, there will be a 'falling over on my arse' incident which more often than not involves pulling mallow roots.

Yes, malva. Love them dearly. This particular plant, and it's only one, doesn't even reseed? Or the conditions aren't right? or?... it hasn't tried to take over in many years. So I assume it's a nice guy.

Just looked up the althea cannabina; the stems look wispy. Is it so? I did miss your offer of seeds earlier, that's very kind. Another lovely mallow.

The sphaeralceas reminds me so much of the flowers on my Chaenomeles japonica shrub. It's so ephemeral, I'd love to see those beauties longer, and sphaeralceas could do that.

Yes, althea cannabina is a tall but 'see-through' plant which would fit very well in your garden, Dee. If only we were neighbours... I will definitely collect seed and send you some in autumn - they are fast, once they germinate, and will flower the first year.

Sphaeralceas are a joy. I have s. ambigua 'Childerly...which would like to get quite large but I am ruthless with secateurs. Munroana and coccinea are smaller and a bit more mannerly. Less keen on sidalcea though - I find them a bit graceless and pink. I have also sown 2 other mallows because they are so gorgeous - corynabutilon x suntense and anisodontea julii. These are not small and dainty - have no space whatsoever (corynabutilon x suntense)