Harden Off Greenhouse Plants Before Transplant

Ever wonder why you’d need to harden off a vegetable starter plant? This term refers to the acclimation process of preparing a plant to move from warm indoor growing conditions to cooler outdoor conditions.

About two weeks before planting, move plants outdoors to an area protected from blustery winds. Each day, gradually give them more sun exposure, but avoid setting out plants when the temperature is below 45 degrees. Bring them in at night and repeat this process.

Hardening off plants applies to vegetables grown from seed, vegetable starter plants, and flowers. Our nursery stock that is outdoors in early spring has already been hardened off for you, but greenhouse plants will still need that extra TLC!

Originally published on January 1st, 2012. Updated on March 28th, 2024.