Help needed for new border

[Rockandgrohl]

I am a new gardener and have managed to successfully grow various things in pots this year, mostly annuals though so i am now hoping to make a perennial/shrub border to but I have no clue what I need to make it look nice or what looks good together and more importantly how many plants I will need! The border will be 4.5m wide and 60-1m wide.
I have various things currently in pots that I hope I will be able to put in (although I don't know if they will be happy together)..these include
A couple of clematis, 3 rudbeckia and 2 echinacea.
I also have a calafornian lilac in a pot and have bought some alium bulbs in white and purple. I do have about 6 tiny pots of Heather too.
So I need lots of plants!! I am thinking maybe a few roses but desperately in need of other ideas please!

How much sun will the border get and what type of soil do you have? That will help to determine which plants are best suited

Sorry..that would help! Its South facing although Im in Scotland so "full sun" probably is stretching it a bit 🤣 Soil is slightly boggy, clay, was thinking id probably add plenty of manure and compost on top and plant into that really.

Alliums don’t usually like clay it might be better to plant them in pots… although I do have alliums in my clay soil, along with lavender and salvias which also aren’t meant to like clay, so it’s worth giving them a go.

Roses do very well in clay. David Austin do lovely roses that you can order online. Roses like to have a bit of space around them, especially in the first few years when they’re getting established.

I love watching Gardner’s world for plant inspiration.

Think as well if you want loads of different plants, or big patches of a few types. I’m on clay and in my south facing borders I have rudbeckia, crocosmia, sedum (hylotelephium), cosmos, astrantia, feverfew, peonies, pot marigolds, gauges, leucanthemum, roses, ceanothus, liatris, penstemon, echinacea. I’m not a frou frou gardener- other than deadheading they go in and they have to survive

Gauges = gauras