Hardening Schedule
Gradually acclimate indoor-grown seedlings outdoors over 7 to 10 days to prevent transplant shock.
Begin hardening when outdoor nights stay above 45 degrees and daytime highs reach 60 to 70. Start with 2 to 3 hours of dappled or morning sun on day one, sheltered from wind and direct afternoon light. Increase exposure by one hour each day, watching for wilting or bleached leaves as signals to pause or retreat. Never leave unattended during initial sessions where animals or strong winds may disturb them.
On days three through five, extend sessions to 5 to 6 hours with gradual sun exposure. By day six, leave them out for most of the day, only bringing them in if temperatures drop below 45 or soar above 85. Resume watering in the morning, not evening, to allow foliage to dry and reduce fungal risk. Lightly brush seedlings daily to strengthen stems and simulate natural wind movement.
Complete hardening by day seven to ten with overnight stays if night temps hold steady above 50. Check root health before final transplant—white, noncircling roots signal readiness. If plants show stress signs like purpling leaves or curling, extend the schedule by two days. A fully hardened seedling withstands full sun, light breeze, and brief temperature swings, doubling its post-transplant survival odds.
