Rather than irrigating on a fixed schedule, Grodan recommends monitoring tray weight. Irrigate when tray weight has decreased by 40–50% from the starting weight. A moderate dryback between irrigation events helps promote callus formation while reducing the risks associated with overwatering.

Transplant-ready cuttings should have 4–5 or more white root tips visibly exiting the sides or base of the plug. Roots should be short, compact and actively growing, with nearly all plugs in the tray showing root emergence.

Relative humidity should be reduced gradually throughout propagation to acclimate cuttings to vegetative room conditions. The Phase 1 model starts at 80–90% RH during days 1–4 and progressively reduces humidity as cuttings approach transplant.

Growers should monitor cutting health, root development, tray weight and environmental conditions throughout propagation. Daily inspection can help identify wilting, damping-off, mold or uneven root development before these issues affect transplant readiness and crop uniformity.