Paeonia lactiflora 'Red Sarah Bernhardt' (Peony 'Red Sarah Bernhardt') is a classic herbaceous peony grown for its big, double, fragrant flowers and long-lived garden performance. You will get the best bloom and strongest stems by giving it a permanent spot and a little patience while it settles in.
Plant it in a deep, fertile, well-drained soil enriched with compost. Choose a site with full sun for the most flowers, though partial shade (especially afternoon shade in warmer summers) can help protect blooms and foliage. Water deeply during spring growth and bud set, then keep moisture steady during dry spells without leaving the crown soggy.
Because the blooms are heavy, you may want to use a peony ring or discreet staking early in the season so the stems are supported before flowers open. Deadhead spent blooms for a tidier look, but leave the foliage through summer and into fall so it can recharge the roots for next year.
In autumn, cut back stems after foliage dies down and clean up debris. Avoid disturbing established clumps; when division is needed, do it in fall and replant divisions with the eyes set shallow so they flower well. With good drainage, sun, and minimal disruption, you can enjoy this cultivar for decades.