Why You Should Harden Seedlings
When plants are grown from seed indoors, they frequently are grown in a controlled environment. The temperature is pretty much maintained, the light is not as strong as full sunlight outside, and there will not be much environmental disturbance like wind and rain. Since a plant that has been grown indoors has never been exposed to the harsher outdoor environment, they do not have any defenses built up to help them deal with them. It is much like a person who has spent all winter indoors. This person will burn very easily in summer sunlight if they have not built up a resistance to the sun. The way to help your seedlings build up a resistance is to harden off your seedlings. Hardening off is an easy process and will make your plants grow better and stronger when you do plant them out into the garden.
Steps for Hardening off Seedlings
Hardening off is really just gradually introducing your baby plants to the great outdoors. Once your seedlings are big enough to plant out and the temperatures are appropriate for planting outside, pack your seedling in an open-top box. The box is not absolutely necessary, but you will be moving the plants around quite a bit in the next several days, and the box will make transporting the plants easier. Place the box (with your plants inside) outside in a sheltered, preferably shaded, area. Leave the box there for a few hours and then bring the box back indoors before the evening. Repeat this process over the next few days, leaving the box in its sheltered, shaded spot for a little longer each day. Once the box is staying outside for the entire day, start the process of moving the box to a sunny area. Repeat the same process. For a few hours each day, move the box from the shaded area to the sunny area increasing the length of time each day until the box is in the sun all day. During this process, it is best to bring the box in every night. Once the plants are spending the whole day outside, then you will be able to leave them out at night. At this time, it will also be safe for you to plant the seedlings out in your garden. This whole process should take just a little longer than one week. Taking this one week to help your plants get used to the outdoors will help ensure that your plants will have a much easier time growing outside.
