Resource Book on Horticulture Nursery Management

Micro Propagation by using Ex-Plants
There are 3 Approaches to Hardening the Plants:
1. Gradual Longer periods of Time Outdoors
2. Place in a Cold Frame
3. Withholding Water
1. Gradual Longer periods of Time Outdoors
a) Begin 7 - 10 days before your transplanting date.
b) Place plants in a sheltered, shady spot outdoors. Leave them for 3-4 hours and
gradually increase the time spent outside by 1-2 hours per day.
c) Bring plants back indoors each night.
d) After 2-3 days, move the plants into morning sun and return them to the shade in
the noon.
e) After 7 days, the plants should be able to stand and bear sun for the entire day and
stay out at night, if temperatures stay around 10 o C. Keep an eye out that the soil
doesn't dry and bake the plants, if the weather is warm.
f) After 7 -10 days your plants are ready to transplant. Try to do so on a cloudy day
and be sure to water well after planting.
2. Placing in a Cold Frame
a) Begin 7 - 10 days before your transplant date.
b) Indoor grown plants can be moved and left in a cold frame, for hardening off.
c) Turn off heating cables and/or open the cold frame cover for gradually longer
periods of time. Start with 3-4 hours and gradually increase the exposure time by
1-2 hours per day.
d) Close the cover and resume heating at night, if temperatures drop below about 4.4
0 C.
e) Plants should be ready to transplant in 7 - 10 days. Try to do so on a cloudy day
and be sure to water well after planting.
<strong>Resource</strong> <strong>Book</strong> on Horticulture Nursery Management : 37