Move seedlings outdoors gradually with a hardening-off record
Bed & Balcony · Care observation sheet · 2026-10-20

For indoor- or greenhouse-grown vegetable seedlings. Hardening does not remove a tender crop's frost limits, and different crops need different outdoor conditions.

OBSERVATIONS
Crop, cultivar and indoor growing conditions:
____________________________________________________________

Planned transplant date and local requirements:
____________________________________________________________

Date, outdoor start/finish and location:
____________________________________________________________

Light, wind and day/night forecast:
____________________________________________________________

Moisture and leaf condition afterward:
____________________________________________________________

Next step: increase / repeat / reduce / transplant:
____________________________________________________________

CHECKS
If seedlings have only grown under cover: Allow time for gradual exposure before the intended planting date. University of Maryland guidance uses one to two weeks as a starting period, adjusted to conditions.

If the day is cold, very windy or likely to scorch plants: Use a protected location or postpone that exposure. Bring tender plants back under protection before unsuitable night conditions.

If leaves wilt, bleach or develop new damage: Reduce exposure and check moisture before increasing it again. Do not use severe drying to force hardening.

ACTION CHECKLIST
[ ] 1. Set a protected starting place
Choose a stable surface sheltered from strong wind, with shade for the first outings. Keep a way to move the tray back indoors. Label crops separately so a cool-season seedling does not set the schedule for a tender one.

[ ] 2. Change exposure in response to the plants
Record the start and finish of each outing, the light received and the condition afterward. Increase exposure gradually when plants tolerate the previous step. If the forecast changes, repeat an easier step instead of following a rigid day number.

[ ] 3. Check the planting decision
Before transplanting, confirm the crop's local temperature and frost requirements, soil readiness and watering access. A tray completing its exposure record is only one part of readiness. Update the garden plan to the actual planting day rather than forcing plants to match an example date.

NEXT CHECK
After each exposure, note the plant response and the next forecast. Proceed, repeat or reduce the next outing; save that decision in the record before moving the tray again.

REFERENCE
University of Maryland Extension: Hardening off vegetable seedlings
https://www.extension.umd.edu/resource/hardening-vegetable-seedlings-home-garden
University of Maryland Extension: Planting vegetable transplants
https://extension.umd.edu/resource/planting-vegetable-transplants

Your notes stay in this file. Review local conditions before acting.