K wrote:
Not as big as Lavatera, but related, and not particularly attractive to
slugs is Musk Mallow -pretty serrated foliage and white or link flowers
all through the summer.

I've grown a lovely white/pale pink this year next to some fennel and
the contrast was so appetising kept making me hungry )

Aquilegia also seem slug hardy

Got carried away and sow far too much hellychrysums. Totally slug hardy
and will last for years, indoors of course. Friends got bored with my
offers of posies ... This year I'll do some gypsofphila in all the gaps.