Handy Gardening Tips On Hardening
December 12, 2022
So, you’ve been caring for your seedlings, watering them and watching them grow for a good while. Now, they are about to grow up, and it's time to ready your plants for the real world!
Plants raised indoors or in a greenhouse need to be acclimatised ('toughened up') in order to handle the cooler temperatures, lower humidity and increased air movement they experience outside. This process takes about one to two weeks before they are planted outdoors in their final growing spot.
Hardening is the process by which these young plants are allowed to acclimatize to the environmental conditions of their new home. Hardening seedlings involves exposing them to cold temperatures for increasing periods of time in order to harden the plant tissue.
"Because the length of time a seedling requires to harden off depends on the type of plants being grown as well as the outdoor temperatures, you need to be flexible when hardening off your seedlings. Prepare to put them indoors or cover them if a late temperature slump is on the way. Be vigilant! Sometimes seedlings can start struggling rather quickly, and if so, you want to take them inside to rest up.
Although each plant has its own tolerance for variability in its surrounding climate, here are a few general steps:
When temperatures are above 45 degrees Fahrenheit, place your seedlings in an outdoor location that is protected from direct sunlight and wind for an hour on the first day.(Move the seedlings indoors when they've reached their daily outdoor allowance).
Increase the amount of outdoor exposure an hour each day, so your plants gradually acclimate to increasing amounts of exposure to the elements.
As you can see, the key to success is gradual exposure to the sun and wind. Don’t put tender seedlings outdoors if the conditions are too far outside of the current norm. Each day, the seedlings will be able to tolerate more hours of exposure to outdoor conditions.
After two or three days in a shady spot, you can place the seedlings in locations that receive morning sun, and over time, gradually expose them even to more direct sun. However, exposing very young seedlings to direct sunlight too soon can scorch the leaves.
If temperatures remain warm both day and night (at least 50 degrees Fahrenheit), the seedlings can usually handle sunlight quite well, and they can also be left outdoors overnight.
After one to two weeks of hardening off your plants, they are ready to be transplanted into the garden or container. If possible, do this on an overcast day, and remember to water well after planting!
