Now that you have successfully started seeds and your plants are healthy and thriving, it is time to harden off your plant starts. If you haven’t started your seeds, see my posts on starting seeds with or without grow lights.
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What is hardening off and why is it important to harden off your plant starts?
Hardening off is the process of preparing your plant starts to transition outside for transplanting. This is the process of gradually exposing your plants to the elements outdoors, i.e. sun, wind, and rain. Thus, ensuring your plant starts experience the least amount of stress. Successfully hardening off your plant starts gives them the best chance of success after being transplanted.
When should you harden off your plant starts?
You should begin to harden off your plant starts seven to fourteen days before you plan to transplant your plant starts outdoors. For summer crops, you will also need to keep an eye on your estimated last frost date and 10 day forecast to make sure the temperatures are suitable for your plants. I prefer to transplant my summer crops outside after the nighttime temperatures are above 45 degrees Fahrenheit. On the other hand, you should transplant your frost hardy crops outside approximately two to four weeks before your estimated last frost date.
Where should You place your plants when hardening them off?
Ideally, you should place your plant starts in an area that is protected from the wind and sun. The goal of hardening off your plant starts is to expose them to sun and wind. However, doing so too quickly can cause your plants to suffer. An ideal location receives partial sun and is protected from harsh winds. If you don’t have a shady place, you can place plants under a pop-up canopy, patio umbrella or shade cloth.
How do I harden off my plant starts?
Hardening off your plant starts is simple; however, it can be time consuming depending on the number of plants you have.
- First, place your plants outdoors for a couple of hours and then bring them back inside.
- The next day, you will increase the length of time your plants are outside by approximately one hour.
- You will continue leaving your plants outside an hour longer each day for approximately 7-10 days.
- On the last day, if your nighttime temperatures are above 45 Degrees Fahrenheit, you can leave them out overnight.
During the hardening off process, you need to closely monitor your plants for any damage as well as make sure they have enough water. I know this process can be time consuming, but I assure you that it is worth it. Following this process, ensures your plants are well acclimated to the outdoors for transplant success.
Example Hardening Off Schedule
- Day one, place your plants outside for two hours in the morning, 8 am to 10 am
- Day two, set plants outside from 8 am to 11 am
- Day three, set plants outside from 8 am to 12 pm
- Day four, set plants outside from 8 am to 1 pm
- Day five, set plants outside from 8 am to 2 pm
- Day six, set plants outside from 8 am to 3 pm
- Day seven, set plants outside from 8 am to 4 pm
- Day eight, set plants outside from 8 am to 5 pm
- Day nine, set plants outside from 8 am to 6 pm
- Day 10, set plants outside from 8 am to 7 pm (if the nighttime temperatures are going to be above 45 degrees Fahrenheit, feel free to leave your plants outside over night)
After you have hardened off your plant starts, you are ready to transplant them outside!
other gardening posts you may enjoy:
- How to Start Seeds Indoors Using Grow Lights
- How to Start Seeds Indoors Without Grow Lights
- 5 Easy Ways to Start Planning Your Garden Today
some gardening supplies I recommend:
- Seed Organizer
- Bulb Planter (great for transplants, too!)
- Women’s Straw Hat
- Auger for Planting
- Book- “The First-Time Gardener” by Jessica Sowards