Plant Hardening Process in Strawberries

Stress

• Indoor plants have a controlled temperature, filtered light and no wind. The cuticle and wax layers of the plant are thinner than outdoor plants. Planting strawberry seedlings outdoors with no adjustment period leaves them unable to adapt to temperature change and drying from wind and sun. Hardening off the seedlings slows growth and causes cell walls to thicken. This makes the strawberry plants stronger and able to withstand sudden temperature changes, retain moisture and handle conditions such as wind and storms that they do not encounter indoors.

Prepare

• People need time to adjust to changes, and so do plants. The process should begin by decreasing the amount of water given to the strawberry seedlings over a week’s time. This alerts the plant to the environmental change and encourages it to reserve resources and slow growth. Don’t let the strawberries dry out completely because young plants need moist soil.

Outdoors

• Place the strawberry plants outdoors on a mild day in a location protected from wind and direct sunlight. For the first day they should be out no more than two hours. Place the seedlings in this protected location, slowly increasing the time over the next five days until the plants are outdoors five or six hours at a time. The seedlings will not be growing during this time, but the leaves will be darker and the stems will be stronger. The texture of the leaves might seem different as the cuticle and waxy layers thicken.

Exposure

• Once the seedlings are spending six hours outdoors every day, they are ready for increased environmental exposure. Move them out of the protected location, preferably to a spot with sun and exposure similar to where they will be planted. Continue to increase the time the strawberries spend outside in the new location over another three to five days, until they are spending eight to 10 hours outdoors in the more exposed location. The strawberry plants will then be ready to plant in the garden and will be better prepared for the shock of having their roots disturbed.