Harden Off Seedlings in 6 Easy Steps
Toughen up your newborn plants prior to transplanting them in your garden.
Young plants pampered in a home or nursery are not ready for a quick transition to an outdoor environment. They are youngsters, equipped with all they need to survive but vulnerable to an abrupt transition from a comfortable inside environment to a harsher one outside. They need a bit of coddling, called hardening off.
To prepare your seedlings for the outdoors, here are six steps that will provide your plants with the best chance of survival. The entire process of hardening off takes about a week.
- Ensure that the seedlings are ready for the transition. For a seedling destined for the outdoors, some days are better than others to begin growing outside. Frost can be the death knell to some young vegetable species, while others are tolerant of frost. Learn the frost date of your seedlings and find the frost dates of your location. The Old Farmer’s Almanac has a free online tool that helps you determine planting dates by letting you know the last date in spring your area can expect frost.
- Suspend watering and fertilizing. Stop all supplemental watering and feeding about a week before you plan to take your seedlings outside.
- Take your seedlings outside for short spells. Find a spot that offers protection from sun, wind, and pets during their first outing. It can be under a table or tree or a shady spot against your home or shrubbery. Place your seedlings outside for just an hour or two in the mid- to late afternoon. At the end of the first outing, move the plants back indoors.
- Lengthen the daylight outings. Each day for days in a row, leave your seedlings outside for longer periods at a time, stretching out their exposure to direct sunlight. As you increase the sunlight exposure, you can also move the seedlings further from the table, tree, shady spot, or wherever they are sheltered. Heed the weather. If the temperatures dip sharply or inclement weather threatens to pummel your seedlings with rain, bring the seedlings inside.
- Lengthen the daylight outings into nighttime. After several days of extending the time your seedlings are exposed to sunlight, prepare them for the nighttime. Gradually lengthen the time your seedlings spend outside until they spend the entire night outside. You have done it! Your plants are ready to be planted in the garden.
- Easy on the watering. Prior to planting, water your seedlings sparingly to help harden them. If they begin to wither, it is time for light watering.
Once you have completed the hardening off period for your plants, let the joy begin. It is time to plant your garden.