Hardening Off Seedlings

Posted on 28 May 2019

Hardening Off Seedlings

Other than overwatering, one of the most common mistakes new and experienced gardeners alike make when growing vegetables from seed is to not harden off the seedlings before transplanting outdoors. 

Have you ever planted your precious tomato or pepper seedlings and a few hours later notice that they are all wilted or the leaves get scalded or turn white? This is often from transplant shock and sunscald. If you do not expose your seedlings grown indoors to the sun and breezes before transplanting them, they will experience transplant shock. Sometimes this can cause the seedling to die or it may have a hard time recovering and have stunted growth. If you don't harden them off first, they will not be used to the sun and can burn easily.

While most seedlings will experience a little wilting after transplanting or in the heat of the day, but if you harden off your seedlings first, the wilting should be reduced significantly and you will prevent sunscald from burning up the leaves.


How do you Hardening Off Seedlings?

It's very simple. You just want to gradually expose any seedlings you start to the sun and outdoor conditions. To do this, first set them in dappled shade for a few hours (or put them outside on an overcast day), and then incrementally increase the amount of sun they receive for a period of several days. Start with a 1-2 hours of sun until they start to wilt, then put them in the shade, then increase the amount of time they sit in the sun gradually to a full day over a week's time. Make sure to protect them from harsh winds or heavy rains during this time. Then for the last night or two, leave them outside so they can also get used to the cooler nighttime temperatures.

Hardening Off Seedlings helps the plants become more hardy and less tender – this means that they won't get sunscald (sunscald will result in white, burned looking leaves), and it also helps them strengthen their stems to stand up to the stronger breezes outdoors. 



When growing peppers from seed, you also should note that peppers really like warmer conditions. They say to wait until it gets 60-70˚ F at night before transplanting peppers outdoors. And, making sure to harden off your pepper plants before you transplant will also ensure that they won't get transplant shock. 

We recommend planting in the evening or in the early morning so the plant has time to recover before the heat of the day with full sun. Overcast days are the best time to plant if possible. Sometimes we'll even shade our recent transplants with a tall pot so that they can have a day without the sun beating on them after transplanting. 

Learn more about hardening off seedlings
and lots of other growing tips here:

How to Grow Peppers »

Pepper Seed Packets

Peppers are easy to grow from seed!
Sandia Seed specializes in unusual and rare pepper seed varieties from around the world, so check out our seed collections for super hot pepper seeds, hot pepper seeds, Hatch chile seeds, and sweet pepper seeds. We also sell super flavorful Heirloom Tomato seeds which go great with chiles. :) 

Happy growing!

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