How to Protect Greenhouse Plants from Frost: 15 Pro Tips

Are you growing some tropical fruits in winter? Or you’re just an orchid lover and can’t survive without smelling your favorite flower for a while? Whatever the case, you need to protect your plants from frost in the winter.

Because if you’re not keeping the temperature warm enough, your plants won’t grow properly, won’t provide you with any fruit or flower, and at worst, the plants will die!

You might have tried every trick in the book yet failed to protect greenhouse plants from frost in the colder months. Yes, the earth is hard, we know. So along with using good quality heaters, you need to know some hacks to get the best result out of it.

So, we brought some simple tricks for you from a few successful winter growers that you’ll find really fruitful.

How to Protect Greenhouse Plants from Frost?

In the era of global warming, the winter still continues to wreak the same havoc as it used to… Hence we can’t avoid seeking help from our greenhouses. So let’s see how to make the greenhouse environment a little more perfect.

Separate the Unused Part

If you’re using just half or less, even more than the half, then you better separate the unused part of your giant greenhouse. This shall provide a decent amount of warmth to your greenhouse.

Or even there is some situation such as you’re growing two kinds of plants where one kind of them may require a stable hot environment while the other might grow with the random greenhouse temperature.

So what you can do is to separate both the sections with a greenhouse partition. This method is best for greenhouses with broader widths. Partitions designed with a door can be a good choice as they’ll let you move and take care of the

Weather Updates

As if owning a greenhouse is a solution! Yes, it is, Only when you reside in a warmer region. You have to spend a tad bit more money and energy to tackle the temperature if otherwise.

Weather updates can give you a better view of the upcoming days, which allows you to apply some tricks before the bone-chilling days hit in.

This will prevent your plants from going into cold shock and prevent you from going crazy in fixing the plant house environment. This just doesn’t require the least amount of time or energy.

Keep Your Electric Cables in Check

greenhouse electric cables

Because you don’t want to wake up to an almost dead garden as your power system had an unexpected issue in your absence. So always make sure everything that supplies power to your greenhouse is doing good.

In fact, consider replacing each and every piece of electric equipment related to your greenhouse heaters. It’s a lot wiser to buy these gears from some renowned store.

Though this might cost you a fortune, it’s going to serve you longer without any pain. Also, if you use gas heaters, don’t hesitate to buy some extra fuel so when you need it unexpectedly, you can use it anytime.

Earth-Bermed Greenhouse

earth sheltered greenhouse

Earth-Bermed greenhouse! Have you ever heard of it?

If you have, you already know that it’s a casual greenhouse built several feet below the ground. So we can call it an underground greenhouse as well. What’s the point of building an underground greenhouse?

The basics are that the soil under the garden has quite the same temperature each month of the year. The temperature there isn’t too cool nor too hot. So it’s a free, nature-gifted heating option to heat up your greenhouse and protect greenhouse plants from frost over the winter.

It’s better to build such a greenhouse on top of a south-facing hill. This is where your greenhouse will reap the benefit of both the sun and the underground temperature.

Snow Removal

When you’ve had quite heavy snowfall out there, your greenhouse must be covered with snow by now. It would help if you didn’t wait till the snow starts to vanish by itself. Else it should keep the greenhouse temperature lesser for longer.

At worst, the heavy snowfall can even put unbearable pressure on the greenhouse, making it collapse. The best idea is to unload the snowbank by using greenhouse heaters.

You can set the thermostat to 70 degrees Fahrenheit and chill while the heavy snow melts off your grow house. It’ll definitely add a little extra expense, but this is nothing compared to the expenses of repairing a collapsed greenhouse.

Plans for Wild Weather

You may have a tough time maintaining the greenhouse environment during heavy wind or storms. If some actions are taken on time, then you can prevent the occurrence of even the slightest damage.

You wouldn’t want to witness your greenhouse getting damaged and your tender, wintery plants being exposed to the vulnerable environment even at your worst nightmare.

After all, a small storm can wreak havoc in just a few minutes. Stay prepared for such unexpected occurrences to save your greenhouse, which also will save the plants inside.

When you sense an upcoming storm, you better remove any obstacles near your greenhouse, such as recycle bins, greenhouse cleaning equipment, drums, shovels. Otherwise, heavy wind can throw these onto the greenhouse, and greenhouse walls can break or get cracked.

Also, look for small holes or broken glass, broken windows, or doors and secure them tightly with tape. Remember, if the wind finds its way to the grows house, it won’t spare anything.

Raised Beds

raised beds in greenhouse

If you haven’t built an underground greenhouse yet, your greenhouse has a ground with a very low temperature. No matter how well you insulated the house or how many heaters you’ve installed, the cold ground will anyhow affect the plants negatively.

Create raised beds to save the plants from the hostile environment. Some plants need dry and cozy soil to grow properly, such as spinach and lettuce. Raised beds are designed to grow herbs or small plants as they don’t have much space or can’t handle big ones.

Fleecing on Colder Nights

Fleecing greenhouse in winter

Be it tarps, horticultural fleece, or row covers, they all help you lock the moisture in. This trick works by increasing a couple of degrees inside the cover.

There’s a few things to consider which otherwise will wreak havoc. If you don’t remove the fleece or tarp during the day, the humidity level will rise too high, inviting mold and pests. Bubble wraps are another cheap or even free option that’ll help you keep frost off your plants.

Black-wood Mulch

greenhouse electric cables

You’ve many empty spaces, including the walkways in the grow house. You can make the best use of the spaces by attaching black-wood mulch.

As you already know that black things are the most efficient to absorb the most heat from the sun; this trick will help you to protect your plants from frost.

Blackwood mulch will absorb tons of heat during the hot hours and release them at night. Non-dyed regular mulches are completely harmless but will stay black for 2-3 months.

Again dyed black mulches will hold the color for almost a year but can be a little harmful to younger plants. You have to place different types of mulch accordingly.

Use Double Glaze for the Greenhouse

double glazed greenhouse

Using double-glazed glass for the whole greenhouse might be very expensive, but the effect and benefit you get are worth every penny. The biggest difference between single glazing glass and double glazing glass is the “Heat retention.”

During the colder days, these glasses are being used to keep the plant house hot, preventing frost from forming on your indoor plants.

Again many growers don’t prefer to spend so much. They can use double glazing glasses only for the windows rather than the whole grow house. This will keep the pocket happy and definitely knock off the frost.

Add Fan Heaters

greenhouse fan heater

Who plans to pass the winter without using heaters in the grow house? I hope no one. You may go for your favorite type of greenhouse heater but make sure to use fan heaters as well. You do not have to use your electric heaters much often while using fan heaters.

The most important thing is a fan heater can distribute the heat produced by other heaters in the house. This prevents some areas from overheating while the other areas become colder. This trick should help you to keep mold and pests in check as well.

Heat Sink

greenhouse heat sink


Please go and wash your dirty utensils on the kitchen sink. Though this shouldn’t help but a heat sink will. A heat sink should be built while making the greenhouse.

It would help if you dug the greenhouse ground, take all kinds of dirt and unnecessary things out of there. You can put big stones or water/wine bottles filled with water beneath the ground.

You have to follow other steps like attaching a fan heater, drainage pipe, portable water pipe, roof tiles, and a few other things. Stone and water are very efficient while absorbing heat, and a fan heater will circulate the heat through pipes to the greenhouse.

Soil Warming Cable

soil heating cable

It’s a kind of electric device that’ll warm up the soil by using electric power. They’re available in different sizes to match your needs.

These are very helpful for hotbeds to make propagation a little easier and quicker. It also is going to help all other plants by keeping the roots warm. But they are extremely useful for floor touching plants to keep them frost-free.

Thermal Mass Floor

Whether you’re building your greenhouse or renovating, it’s time to add concrete, tiles, or slate to the floor. These objects can capture heat in the colder months very easily, which helps keep the greenhouse warm during winter and dark hours.

But, interestingly, the same objects feel a chill while touching during the summer days. So you can apply this trick to protect your greenhouse plants from frost without paying a penny (requires installation cost only).

Place the Heaters Accordingly

You surely don’t grow one type of plant in the hothouse. There’s a variety of plants that every grower grows in the greenhouse.

Some need high heat, and some are okay to grow with a little low temperature. You can place the heater near those tender plants and put the cool loving plants a little away.


A winter grower has to work really hard, but some of them aren’t successful in growing plants properly. At some point, they find it very difficult to do the job properly.

These tricks shared above should help all those growers immensely. Some methods work for free, while some require plenty of money. So feel free to apply them wisely and show your skill this winter.