garden centres will wait till they are in flower before displaying them for sale because they can charge more for them. Available on line various places currently, google Hibiscus suppliers UK, but make sure you select hibiscus syriacus if you want one that's hardy outdoors in the UK

Hi Eiryangela you could try typing Hibiscus into the search bar top right of your screen, It will give you a drop down menu and a list of sellers of that plant, hope this helps.

I'd do a google search and then check for suppliers nearest to you etc. if you can see the plant in the garden centre then you will get the colour and size you want.
welcome to GoY too :o)

Saw some in a Wyevale gc, small though, not sure they would flower this year, a bit frost tender too

Bamboo is right, my local garden centre holds them back in the nursery as they are late to come into leaf and flower. Customers always are attracted to buy shrubs and plants generally when they are in flower.

Thank you all.