How Cold Can Seedlings Tolerate

Planting garden plants from seed can be a nerve-wracking experience, especially if it is your first time attempting it. This can be made even worse if you live in a climate that can be somewhat unpredictable in the spring, as many seedlings are sensitive to overly cold and overly hot weather. So, how cold can seedlings tolerate?

Most seedlings can tolerate temperatures between 60 – 80 degrees Fahrenheit. Temperatures near or below freezing can cause seedlings to wither and stunt root development.

This article will explain everything that gardeners need to know about how much cold temperature seedlings can tolerate. 

What Temperature Is Safe For Seedlings? 

Generally speaking, seedlings tend to best in temperatures between 60 and 80 degrees Fahrenheit. However, some seeds will do fine in more extreme temperatures than this. Most seedlings do not do well in temperatures that are below 40 degrees.  

What Is Too Cold For Vegetable Seedlings? 

Most of the time, temperatures that dip below 40 degrees Fahrenheit are too cold for vegetable seedlings. It is recommended that you either cover your seedlings or bring them indoors when the weather dips below this temperature and poses a risk of frost. 

Can Seedlings Survive 40 Degree Weather? 

Yes, many seedlings can survive 40-degree weather. However, this may slow down their growth if they are exposed to colder weather for an extended amount of time. Similarly, many seedlings will also risk dying or becoming damaged in weather colder than 40 degrees Fahrenheit. 

At What Temperature Do You Need To Cover Plants? 

It is a good idea to cover your plants and seedlings at around 40 degrees Fahrenheit, and you should cover them if the weather may get even colder. Covering your plants and seedlings during unexpected cold fronts can help prevent frost damage. 

You can use tarps, blankets, or sheets when covering plants. Covering plants and seedlings works to protect them from frost damage by trapping heat and shielding your plants from the frosty air. 

How Do I Know If My Plants Are Too Cold? 

There are a few ways gardeners can tell if their plants are too cold. As we have mentioned previously, some plants may not be as equipped to survive cold temperatures as others, and in these cases, even 50 degree weather could potentially damage them. 

The main way to tell whether or not your plant is too cold is by taking note of its appearance. If your plant appears healthy, they are likely doing just fine.

However, if your plant appears to be wilted or if they have discolored leaves, then it is likely that your plant is too cold. Some other signs that a plant is too cold are loose roots and signs of mushiness. Some plants may even start to turn black when they start to die from being too cold. 

What Happens When Seedlings Get Too Cold? 

When seedlings get too cold, they often don’t germinate. This means that nothing will grow in the areas where these seeds were planted. However, if your seedlings have started to sprout and they get too cold, a couple of things can happen. 

The first potential consequence of sprouted seedlings getting too cold is that they will grow and develop much more slowly. This isn’t necessarily an overly bad thing, but it will likely mess up when harvests come in and when your plants will develop. 

The second potential consequence of having seedlings get too cold is that they could die. Damaged and dying sprouts will look similar in appearance to full grown plants that have been damaged by the cold. Appearing wilted and having discolored leaves are common signs of frost damage in seedlings. 

How Do You Revive A Plant After Frost? 

The good news is that many plants will not completely die from a small amount of frost damage. The best thing that you can do to revive a plant after a frost is to keep them warm by either bringing them indoors or covering them. 

Then, the next thing you should do is prune the damaged parts of the plant as the weather gets warmer. Damaged parts of the plant will appear to be droopy and discolored. Usually, the damaged leaves will be brown in color. 

Of course, plants that completely die due to frost damage cannot be revived. Dead plants will likely be brown and droopy all over, and they can also appear mushy and rotted. Unfortunately, the only thing you can do with plants that cold temperatures have killed is to throw them away. 

Things To Consider 

There are some other things that gardeners should consider regarding how cold of temperatures that seedlings can tolerate. These things include when in the year is the best time to plant seedlings and if it is better to start seedlings indoors or outdoors. Here are some additional things to consider about planting seedlings and what temperatures they can tolerate. 

When In The Year Should You Plant Seedlings? 

If you are planting seedlings outside, it is best to plant them soon after your final frost of the season. Normally this is sometime in early to mid-spring, depending on your climate. If you start your seedlings indoors, you can plant them earlier than this. 

Is It Better To Start Seedlings Indoors Or Outdoors? 

Whether or not it is better to start seedlings indoors or outdoors depends entirely on the gardener, and there are pros and cons to both.

Many gardeners prefer to start their seedlings indoors because it protects them from the harsh elements early on. This is because things like extreme temperatures, too much rain, and even too much sunlight can potentially damage delicate seedlings. 

However, when planting seedlings indoors, you will likely need to transplant them outside at some point. For gardeners who do not like transplanting their seedlings, starting seedlings outside may be better. This is especially true for gardeners who live in warmer climates that do not need to worry about frost damage as much.