Can tomato seedlings survive frost? | + Best ways to protect them

Tomato seedlings can survive frost if the frost is light and most of their leaves remain undamaged. Frost will damage the new delicate leaves on a tomato seedling turning them a darker color on the tips and causing them to wilt. To help them recover water the plant well, add a dilute addition of liquid nitrogen fertilizer and surround them with mulch.

Tomato seedlings will survive a light frost and will grow new leaves to replace the damaged ones. Leave the damaged leaves on the plant until you see the seedling start to recover and grow new ones.

Pinch off damaged leaves and the seedling will soon recover when the weather warms in Spring.

What happens when tomatoes get frost damage

I am always excited to get my tomato seedlings in the ground in Spring but sometimes this eagerness means my plants can be hit be Spring frosts. Living in an area of Australia that would often get late Spring frosts it was always a judgement call as to when I should plant them out into my garden.

Frost damage can be harsh and kill the plants overnight. Very young tomato plants that are less than 2 inches tall will suffer greatly from a harsh frost and may not recover.

Larger seedlings that are at least 3 inches tall will have more of a chance of surviving a Spring frost. Here is how to tell your tomato seedlings have suffered frost damage


Frosts can cause tomato seedlings to wilt at the ends of the leaves and the center leaf sprouts. This can just affect the leaf tips of affect the entire seedling.

Dark leaf tips

Damaged leaves will turn darker on the end and start to shrivel up as the leaf has been frozen by the frost. The frost will damage the leaf cells, freezing the liquid and then bursting the cells. This will stop the leaf from holding the structure it normally has.

How to help seedlings recover from frost

Seedlings that survive a frost coverage can not only live on but thrive afterwards. They will need some care to recover well so here are some tips to deal with frost damaged seedlings.

1. Water the plant well

Watering the tomato seedling well will help it to recover from frost damage. It can be easy to forget to water the seedling when it is cold but moist soil is important to help it recover from frost.

Water the tomato seedling at the base on the soil around the roots and keep the water off of the leaves.

2. Dilute nitrogen fertilizer

Adding a small amount of liquid nitrogen fertilizer to a watering can and applying it to the seedling will help it recover from frost. You could use liquid fish emulsion or another organic liquid fertilizer but either way, this will help your tomato seedling recover quicker.

3. Protection

Keep a look out on the weather forecasts for upcoming frosts and be ready to protect tomato seedlings. For those already planted out into garden beds, cover them with a plastic covering like a clear plastic bag.

Placing 3 stakes around the outside of the plant and placing a bag over the top will stop the frost from settling on the leaves and prevent further damage. Remember to take the plastic covering off during the day so the plant does not heat up too much.

For seedlings still in trays or pots, these can be placed near a garden wall, in a greenhouse or underneath a pergola. Anything that will stop the frost from landing directly on the leaves.

Frost will settle onto exposed leaves so any protection you can add over the plant will prevent the frost from landing directly on the leaves.

How to prevent frost damage on tomato seedlings

Prevention is best when dealing with tomato seedlings and how you do this will depend on whether your seedlings are still in a tray, a pot or in the ground. Here are some tips for preventing frost damage on tomato seedlings.

They will survive better in a greenhouse

For young tomato plants that you have raised by seed or have bought home from a nursery they will survive better if transitioned gradually out to your garden.

A greenhouse will protect them from late night or early morning frosts. The plant can then be gradually moved out into the directly sunlight. Start with 2-3 hours in the morning sun and gradually increase it.

This means you can avoid the early morning frosts and cold weather while still ‘hardening them off’ in the outdoor sun.

Preventing frost damage in potted tomatoes

For tomato plants that have been planted out into pots they can be protected easily in early Spring. Move the pot near a garden wall or underneath a garage awning or pergola. The plant can then be gradually moved out to an exposed area in later Spring and Summer.

Tomato seedlings in garden beds

Preventing frost damage on tomato plants in garden beds is more challenging but can be done. Use a tomato cage or 3x stakes around the outside of the plant. Drape over some clear plastic and make sure it is closed at the top. This makes the perfect greenhouse and protection for your plants.

Can tomato seedlings survive frost? | Summary

Tomato seedlings can survive frost if the frost coverage is minimal and any damage caused is not too bad. It is better to protect your seedlings from the frost if you can by using clear plastic, a greenhouse or shelter for small plants.

Severe frost damage can be devastating to tiny tomato seedlings especially if you have gone to the effort of growing them from seed. Protecting them in early Spring is much better than needing to start again with new plants if they are hit by a heavy frost.

Protect your tomato seedlings when frost is predicted and you will save your plants.

Happy growing.