Getting a greenhouse can be an exciting decision. It allows you to extend your growing season, so you can keep beautiful plants or a fresh vegetable garden year-round.
On top of that, greenhouses often look beautiful. The right one can take a plain yard and turn it into a garden haven worthy of a magazine cover.
But just having a greenhouse doesn’t guarantee your plants will thrive. Without taking the proper measures, your garden might not even survive the winter.
We’ve written this guide so you’ll know how to keep plants alive in a greenhouse in the winter.
Choosing a Greenhouse for Winter Growing
It should be no surprise that, when it comes to winter growing in a greenhouse, you should start by considering the design of the greenhouse itself. Some greenhouses incorporate design elements that naturally make them better for maintaining a garden in the cooler months.
Slanted roof panels are an example of a feature that makes winter growing easier. Because they’re at an angle, sunlight can filter in through them even when the sun is low in the sky.
Additionally, when the roof is at a slant, snow isn’t able to accumulate on it as easily. Most of it will slide off, so you don’t have to worry about your greenhouse collapsing under the weight of snow.
Built-in shelves are another great quality. They free up more space on the floor by giving you room to store your potted plants.
If you’re not sure what kind of greenhouse to get, you can check out our list of some of the best ones for winter growing here.
How to Keep Plants Alive in a Greenhouse in the Winter
Pick a plant that’s ideal for growing in the winter.
Some plants are naturally better at growing in cold conditions than others. For example, spinach and lettuce and are two vegetables that are adept at survival in the winter.
To make things much simpler for yourself, you should plan ahead what you want to grow. Choosing a hardy winter plant could save you a lot of effort, since it won’t take as much energy on your part to keep it alive.
Not sure which plants to choose? We’ve got you covered – you can read our list of plants to grow in a greenhouse in the winter here.
Know your plant’s winter care routine and stick to it.
After you’ve chosen what you’re going to grow, it’s time to do just a little extra research. Read about your plant and, more specifically, what it needs during the winter.
Some plants go through period of dormancy for a few months. Others might grow virtually the same year-round.
By understanding your plant’s requirements, you’ll know how to recreate the perfect environment inside your greenhouse.
Set up your greenhouse in a good spot for sunlight.
Location is also highly important for greenhouse winter growing. The goal of your greenhouse is to provide a warm climate that protects your plants from frost, and you can’t achieve this if you put your greenhouse in the wrong spot.
If you’re in the northern hemisphere, you should try to put your greenhouse on the southern side of your property. It will work best when it faces north and south, rather than going from east to west.
In the southern hemisphere, you’ll want your greenhouse to be on the northern side, still facing from north to south.
These positions will ensure your greenhouse gets as much sun as possible. There’s naturally less sunlight in the winter, and so you’ll need to make each hour of sunlight count.
Heat the roots of your plants.
Heat is critical when it’s cold outside, so many of the things you’ll need to do to keep your plant alive involve getting them warm.
However, heating an entire greenhouse can get a little pricey. If you don’t have the budget to put a complex heating system in it, there are things you can do to insulate your plants for a low cost.
Choosing to heat their roots as opposed to the entire greenhouse is one such option. There are seed-starting heat mats you can use, but the heating pads you’d use for aching muscles work, as well.
You can find them at just about any pharmacy. Once you have them, lay them on the table, shelf, or bench, then place your potted plant on top of it.
Store large barrels of water in your greenhouse.
This is another low-cost trick you can do to heat your greenhouse. We discussed this method in our guide about heating your greenhouse for free in the winter.
The way it works is simple. Bodies of water often store heat during the day, and then release this at night, just like a solar-powered battery.
You can use this property by keeping large barrels of water in your greenhouse. Our personal recommendation is to use at least 55-gallon barrels, because they’re a large enough size.
Also, the more, the merrier, because they’ll all give off some much-needed warmth when the sun goes down. Here is one example of a water storage barrel that you could use.
Cover your plants.
We know it doesn’t necessarily look the greatest, but covering your plants will keep them nice and toasty in the middle of a freezing winter. You could use a cloth like this and lay it over your plants at night, when the temperatures drop.
During the day, we suggest taking the cloth off again to prevent your plants from overheating.
The greatest thing about this strategy is that, like with some of the others in this guide, it doesn’t cost you very much to do. It also doesn’t take a lot of skill to do it – all you need is to drape the cloth over your plants, and you’re done.
Consider installing a heating system.
A heating system combined with a thermostat will be the lowest-effort way of keeping your greenhouse up to temperature. It can be costly, but if it’s within your budget, a good heating system will protect your plants the best.
There are many different kinds of heating systems out there. An electric heater can work pretty well for small greenhouses, although gas ones are more powerful.
You can read more about choosing the right type of heating for your greenhouse here.
When it comes to keeping a greenhouse in the winter, heat is going to be your biggest challenge. This is particularly true at night, when the sun falls and the temperatures drop.
That being said, with just a few steps, you can ensure the survival of your garden. If you choose winter-friendly plants, a good greenhouse design, and use some of the methods in this guide to create a warm environment, your plants will stay alive all winter long.