Best Perennial to sow

[MightyGoldBear]

I'm looking for a good hardy perennial to sow to really bulk out borders and add some repeat planting colour structure.
My key colours are purples whites and oranges. Not adverse to other colours/hues either.
I'm looking for something I can sow lots of and get a fair few plants from.
Any ideas ?
Thanks

What is your soil, moisture levels, and would it be full sun/part shade/shade?

Given that I never planted it, but had most likely been a seed in a bag of community compost, Verbena Bonariensis. I am useless at growing plants from seed but this has self seeded all over my garden - sun, shade, wet soil. I’ve not cut it back so far but 2023’s seedlings are still pretty much evergreen.

Those perennial jewel colour wallflowers are lovely for spring, and can flower for months. Erysimum winter sorbet is one.

Geranium rozanne-utterly reliable blue.

Dahlias are great for August to October .

Veronica spica's is nice, and provide the spiky shades in the flower. Plus white veronicastrum.

I also like Ashanti's-there are blue, purple and white varieties.

Lavender , dailies and penstemons are options, and my penstemons go on for ages.

Jacob's ladder are growing well from seed for me - purple with very pretty foliage.
Second verbena bonariensis
Ammi majus or ammu visnaga
Wallflowers and sweet Williams are sold as biennial but often go on for years- wallflowers have the most fabulous orange and rust colours

Oh and might not gi longer than biennial but for impact and structure can't beat foxgloves!

I find my geums are very reliable and fast growing, and also easy to divide when dormant. I have an orange variety but can’t remember the name (possibly Totally Tangerine?) I also have a white aquilegia that is very pretty and comes back each year; also successfully grown from seed.

Good ish soil slightly leaning towards the clay side, we get a lot of wind very open as we have open fields behind us and lots of sun in the summer so mostly full sun or part shade. There is pockets of more protected places so anything tender goes in those spaces.

Lots of good ideas. I think my problem is I'm very lucky to have a large garden so need so many to bulk everywhere out and I just love all plants so I want them all 🙈 might just have to accept its going to be a slower process. Unless I had Alan titchmarshes budget which I definitely do not !

Lots of salvia's are purple/blue, some white. Avoid 6ft Giant though
Lavender is you have bad soil & full Sun somewhere
Rosemary
Geranium Rozanne or other Cranes Bill varieties
Verbena (not just Bonariensis, but also Hastata & Bampton)
Lovage
Valerian
Deadnettle
Miniature Buddleia

I've spent the past year redoing my garden with infect & bird friendly perennials & the majority have been bought in the clearance sections of garden centres. So if you want to give yourself a head start, go to some now - a lot of these types of perennials are reduced as they're just stumps in pots at present & much harder to flog than full leaf plants.

Agastache is a great plant in my garden. Blue/purple flowers, seems to flower for half the year.

Chiltern Seeds is a good source of perennial seeds.