Delphinium plants in pots from a garden centre - should I separate them, or just plant the clumps?

[sprigatito]

There seem to be about 3 plants in each 15cm pot, very close together. The biggest plants are about a foot tall, no evidence of flower plumes yet but lots of really healthy foliage. Should I separate the roots out and plant them individually, or just leave them in clumps? Don't want to kill them, but would really like more plants to fill more space if it's possible! As a side note, I can't bloody get delphinium or larkspur seeds to germinate! Have done the cold/moist stratification and all that gubbins, then planted in good seed compost in seed trays, kept moist....no cigar. Any tips?

Bumping for the evening crowd

Adding a bump because I'd love to grow delphiniums successfully (in my new garden when I move- yay) but any time I've tried them they've been munched up by slugs. 😡

I'd spread the clumps out so the flower spires have room when they come up.

Prepare for slugs OP!

I'd also spread them out so you can add in stakes for support (if they don't get slugged on)

You’ll probably get more impact leaving them as they are for the next couple of years. They multiply quickly but I’d plant in odd numbers to give blocks of colour. Fill any gaps with annuals whilst they grow. Maybe something like white cosmos?

Oh great, I will separate them then! I have loads of healthy cosmos seedlings that can go in with them, that's a good shout - thanks!

Also would like tips on how to make them germinate. Every year, I try, and every year, I fail.