How to Prune tulip 'Glück'?
Deadhead after flowering and remove fallen petals

tulip 'Glück' · Tulipa 'Glück'
Grow in fertile, well-drained soil in full sun. Protect from strong winds and excess winter wet. Kaufmanniana Group tulips may be left in the ground for several years, they do not need to be lifted annually. See tulip cultivation for more details
Deadhead after flowering and remove fallen petals