Should I wait for each season?

[KoolKoala07]

This maybe a silly question with an obvious answer.
We are overhauling our garden completely. I've basically started with bare borders and I'm keen to fill with perennials.
I've chosen lots of different ones already because I like their leaf colours, shape etc and want to keep them varied for interest.
Should I refrain from buying anymore now and wait until spring/summer for different choices or will they be selling the same all year round?
Don't want to fill my borders up and then discover lots of different ones that I love next spring/summer.

You don't want to fill them up anyway as s they will grow and fill the spaces. Are you just choosing for colour and leaf shape or growing conditions light, share, soil type?

I find borders are work in progress, never final. Some things don't grow, die, are in the wrong place, and gaps I usually fill with annuals until them perennials around them meet. And some things we sold all year round, some aren't and some rarer things are only available from specialists.

Thanks for replying.
Yes I've been choosing based also on the extra things you mention. I'm hoping I've got it right or at least almost correct. It takes me ages to read all the labels of the plants that catch my eye whilst walking around the garden centre!
I've also planted them so that there is plenty of room for them to fill out. At the moment it all looks a bit sparse.
I think will hold off a bit and see what I can get next year and also to see how well my current planting skills have worked.

I’d start with a few structural plants, such as Pieris, fuschias or hydrangeas. These could be planted now, while the soil is warm and often sold more cheaply as it’s the end of the season.
Then I’d put in some spring bulbs for early colour. They can always be lifted when finished and repositioned.

I'm hoping I've got it right or at least almost correct.

Sorry but there is no such thing as correct.

I am a trained horticulturalist, and have taught hort for 7 years and every year we moved stuff, try different places and positions, add new things, take things way that have not worked. Please don't think of it as correct or not!

Also, the soil inbetween, my top tip would be to make sure it is covered whilst you are deciding. It keeps the moisture in, the weeds down. Bark chippings are good as they break down and the fungi that grow there help your plants to take in nutrients. I use all my path mowings straight on top of any bit of soil that is open. It really is the best way to keep a border practically weed free.

I have planted some things in pots, so I can move them around the garden until I'm happy they are in the right space.

Great, thanks for the tips! Will put these into practice. I'm learning slowly.
The garden already looks a million times better and our neighbour who's a very keen gardener complimented me today. Maybe she was just trying to be nice
Really motivated now to carry on.