Looking for a step by step guide for hardening off seedlings easily? Got a busy schedule and not sure how you’ll be able to prepare your seedlings for the outside elements? Keep reading for the simplest method for hardening seedlings.
With spring quickly approaching and the days getting warmer, its time to start preparing your seedlings to transplant outside. Hardening off your seedlings is an essential step in the gardening process, as it helps your plants acclimate to outdoor conditions and prevents transplant shock.
But let’s face it, not everyone has hours to spend carefully transitioning their seedlings from indoors to outdoors. That’s where my tried and true method comes in. In this blog post we are going to learn about the purpose of hardening off seedlings and then walk through my simple step by step process so you can harden off your seedlings even with a busy schedule and long to do list!
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What is Hardening off Seedlings?
Hardening off seedlings is the process of gradually exposing them to the outdoor environment, such as direct sunlight, wind, and temperature changes. This important step helps prepare the young plants for their new environment and prevents them from going into shock when transplanted.
Without hardening off seedlings they may struggle to adjust to the outdoor elements which could delay their growth and your eventual harvest. Stressed seedlings are also more prone to disease and pest pressure as pests are drawn to stressed and struggling plants.
When should you harden off seedlings?
Seedlings are transplanted based on their cold hardiness and your frost date. Seed packets typically have this information listed, or you can do a quick online search for your specific plant. Generally speaking, cool season crops can be transplanted anywhere from 4-6 weeks before your last frost date with protection from colder temperatures. It’s a good idea to wait to transplant Frost-sensitive plants until after risk of frost has passed.
Hardening off plants should happen at least a week before you intend to transplant. Be sure to check your weather forecast. You want to avoid times when there will be strong winds and look for a cloudy day to start the process.
How to Harden seedlings for transplanting
If we understand that hardening off seedlings is important for the health and wellbeing of our seedlings, and we know the purpose is to prepare our seedlings for the outside world we can easily build a hardening off process that works with your schedule.
Here is how I harden off seedlings.
Step 1: 2 weeks before transplanting complete indoor preparation
Hardening off your young seedlings actually starts with your seed starting set-up and environment. In order to have strong and healthy seedlings that are capable of surviving the outdoor elements, they need proper care indoors as well.
You want to make sure that your seedlings are getting adequate light(using a grow light), the proper amount of water, and nutrients. Keep an eye out for any signs of disease or pests and address them immediately.
Placing an oscillating fan near your seedlings and occasionally brushing lightly against the seedlings can help strengthen the stems and build stronger and healthier crops. I really like this fan for my grow space!
Additionally using a warm greenhouse as an intermediate step to the hardening off process can save a lot of time.
Step 2: 6-8 days before transplanting, 1 hour outside
During first day or two of the hardening-off process, we will move our seedlings outdoors to a shaded area for approximately an hour. Position them where they receive shade but are still shielded from excessive sunlight. The optimal time for this task is in the early mornings as morning sun is far less intense and more forgiving then late afternoon sun.
Personally, I prefer setting a timer before starting work to take them outside to a sheltered spot and bring them back indoors before leaving. If mornings are not feasible, evenings are also a suitable alternative.
Step 3: 3-5 days before transplanting, 3-4 hours outside
After a couple of days of an hour gradually acclimating your seedlings to the outdoors, you can consider extending the time to 3-4 hours. It’s important to continue avoiding the peak heat around noon. By planning effectively, you can schedule this process on weekends or during consecutive off days. This approach allows you to be available to bring your seedlings back indoors after their time outside for this step of the hardening off process.
Step 4: 1-3 days before transplanting, 6-8 hours outside
Lastly, you’ll extend the time your seedlings outside a little longer. Now you will want to make sure they experience the warmest part of the day and full sun. I generally put my seedlings under a shade cloth as well. This ensures that there is still some protection from the heat of the day. This can be done on days when you go to work, and just be prepared to bring them in once you get back home.
Step 5: Transplant seedlings
After the plants have been successfully acclimated to the elements , you can transplant them into your garden beds. Be sure to water them in well and provide any necessary support or protection for the newly transplanted seedlings such as a cold frame, row covers or cloches.
Also read: Successfully Transplant Seedlings after Germination
Frequently Asked Questions
Still have questions about hardening off your seedlings?? Here are a few of the most common asked questions! And if you are still unsure of something! Shoot me a message on instagram or tiktok! I love helping out fellow gardeners!
How long should you harden off seedlings?
Typically the transition period for hardening off your seedlings lasts around 7-10 days. The slower and more gradual the acclimation process of increasing the length of outdoor time, the better prepared and stronger your seedlings will become to thrive in their new home. My personal experience has been great with at least 1 week.
Can you skip hardening off seedlings?
While you can skip the hardening off process, this could be a fatal error for the health of your seedlings and should not be skipped. After taking the time of caring for and growing your seedlings, skipping the hardening off process for your baby plants would be similar to launching your children without proper preparation.
The goal of starting seedlings is to get a jump start on the growing season, and skipping the hardening off process can significantly set-back your garden season and make your hard work for naught.
What temperature do you start hardening off seedlings?
The ideal temperature for the hardening off process is going to depend on the seedlings you are hardening. Generally, you will want to start hardening off seedlings when temperatures are consistently above 50 degrees Fahrenheit (this is particularly important for warm-season crops). However, some more cold-hardy plants can be hardened off in cooler temperatures.
Can I leave my seedlings outside overnight?
During the hardening off process, it is recommended to bring your seedlings back indoors overnight. This will help protect them from any unexpected drops in temperature or harsh weather conditions. In fact, even after they have been successfully hardened off and are ready to go into the garden, they may still require protection for harsh nights.
How do you harden off seedlings when you work?
Gardening as a working individual does require some pre-planning and time management skills. To harden off seedlings while working, you can schedule the process on weekends or days when you have consecutive off days. You can also try to incorporate it into your evenings after work, just make sure to bring your seedlings back indoors before going to bed. Setting a timer can also help with this process.
Conclusion
Hardening off seedlings may seem like a daunting task, but with my easy step by step process, you can do it even with a busy schedule. Just remember to start at least a week before transplanting and gradually increase the time your seedlings spend outside.
I hope this guide on hardening off seedlings has been helpful for you and your gardening journey! Remember, it’s important to give our seedlings the best start possible by properly acclimating them to the outdoor elements.