Hardening Process

During the spring season, we grow our plants in our greenhouses. Due to the warmer temperatures inside, they are not acclimated to the outdoor temperatures. In order to plant outside, they have to go through a process called "hardening off."

From The Pennsylvania Extension Office Steps for Hardening Off Plants:

• When temperatures are at least 45-50ᵒF, move plants outdoors to a shady, protected spot.
• Initially, place them in a shaded, sheltered location for two to three hours.
• Gradually increase the amount of sunlight the plants receive over the two weeks. On the last day or two, they can spend 24 hours outside.
• Reduce the water plants receive, but do not allow them to wilt.
• Avoid placing seedlings outdoors on windy days.
• Cold frames are excellent places to harden plants, but another spot that provides protection, such as a porch, will work.
• Pay attention to the weather forecast; if temperatures fall below 45ᵒF, prepare to bring the plants inside.

Keep in mind that the overall goal of hardening is to slow the growth of the plants to allow them to adjust to a change in conditions. After proper hardening, even warmth-loving vegetables, such as tomatoes, can withstand an unexpected dip in spring temperatures.