hardy hibiscus

If you are talking about Hibiscus syriacus, any Garden Centre or Nursery will have them at the moment, as they are in flower.

Hibiscus late flowering shrub are very fussy plants - well drained soil, shelter from cold winds, in a sunny spot and slow to establish. You can get an annual Hibiscus also. Mine has flowered this month but not many and I planted it 2 years ago.