Weather acclimation of plants

Acclimating plants grown inside or in a greenhouse is called hardening off. Hardening off thickens the cuticle of their leaves to avoid access moisture loss and strengthens tender young plants. If you are planting potatoes, onions, asparagus, strawberry bare roots, or anything completely under the soil you do not need to take these steps.

Slowly acclimating plants to lower temps, less humidity and strong winds will reduce stress to your plant.

How to harden off plants grown inside or in greenhouses:

Hardening off takes 1 to 2 weeks depending on the weather and available time. When there is a very windy day, heavy rains or quick rise in temps on clear sunny day avoid direct exposure when you are going through the hardening off process.

*Best to do this when temps are 50F or above. Cold-tolerant plants can handle ~40F temps when starting this process.

1st day: Put your plants outside in a shady spot for 1-2 hours
2nd day: Place in dappled sun or early morning sun for 1-2 hours
3rd day: Place in dappled sun or full sun for 2-3 hours
4th to 7th day: Increase full sun an hour or two each day. If overnight temps are warm enough (~50F) between the 4th-7th day, it’s usually safe to leave them outside in their containers.

Acclimate slower if you see signs of stress. Signs of stress can be quickly can be wilting in the sun, scorched leaves, and/or drooping. Movement from the wind is beneficial but not in excess to cause complete drooping over for long periods.

Make sure you check soil moisture frequently. Water when the soil is partially dry so your plants start developing roots that reach further down to the moisture.

How to harden off perennials grown under sun protection:

During the sunniest and warmest part of the year, perennials growing under shade cloth may benefit from a quick 2-3 day acclimation. When you buy plants grown under shade cloth that have already been exposed to wind and fluctuating temperatures, hardening off is focused on increasing sun exposure for full sun perennials. Shade perennials should go in the ground right away.

It’s a quicker process than annuals and if you choose to plant during consecutive cloudy and cool days, planting in their permanent spot is usually fine!

Reminder to check the soil moisture daily. Water your plants when the top few inches of soil are dry.