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How to Build and Maintain a Winter Greenhouse

Using a winter greenhouse is a fantastic way to grow your own food.

Imagine picking fresh leafy greens, herbs, radishes, and even tomatoes in the middle of January. A well-tended greenhouse makes it possible, even in cold climates.

If you want to start growing your own year-round garden, keep reading! Here’s how to build a winter greenhouse.

winter greenhouse

Choose a Design

Greenhouses come in all different shapes and sizes. The first step is to decide what type of greenhouse you want and how big it should be.

Budget

Set a budget before starting your greenhouse. That way you’ll know what you can afford. You can find nice greenhouses in a wide range of price points

Keep in mind that you’ll need shelving, tools, and other supplies inside your greenhouse. Factoring those expenses in at the beginning makes it easier to stick to your budget.

How Big Should the Greenhouse Be?

There are several considerations when it comes to size:

  • How much space you have available for the structure
  • How many plants you want to grow
  • What types of plants you want to grow (tomatoes need more space than herbs, for example)

Climate

You need something suited for the weather where you live.

pop-up greenhouse may work great for a mild southern winter, but it’s not ideal for very cold climates. That’s because heat easily escapes once the sun goes down.

In a very cold climate, you’ll want a sturdier greenhouse that provides better insulation.

Making a Decision

Think realistically about your space, budget, and climate concerns before settling on a design for your winter greenhouse.

For more tips on choosing the right greenhouse, check out How to Design Your Ideal Greenhouse.


How to Build a Winter Greenhouse

Once you know what you’re looking for, it’s time to figure out how you want to build the structure.

Build a Greenhouse Using a Kit

Purchasing a kit is one of the easiest ways to start a winter greenhouse.

Kits like this one from Amazon include everything you need plus easy to follow instructions for how to build the structure.

You can find large designs like this very nice cedar greenhouse from Tractor Supply, as well as simple kits like this lean-to from Amazon.

Basically, whatever type of greenhouse you want to build, there’s a kit for that!

Build a Greenhouse From Scratch

If you have some experience with home projects or construction, you may want to build a greenhouse from scratch using lumber and other supplies.

If you go this route, consider purchasing greenhouse plans to simplify the process. Having a good set of plans makes the building process much easier.

Supplies can be purchased from your local hardware store or online from places like Northern Tool or Tractor Supply.

You could also design your own greenhouse using scrap wood, old windows, or other supplies you may already have on hand.

winter greenhouse

Filling the Greenhouse

Building the structure is just the first step of setting up an effective winter greenhouse. Next, you’ll want to fill the greenhouse with plants and tools that make it functional and productive.

A Space for Plants

Shelves, long tables, or even the floor of the greenhouse all work well for holding plants.

Large open shelves allow you to maximize space, making room for more plants.

Work Surface

You’ll need a place to pot up plants, start seeds, and do similar tasks. Here are some ideas for things that work well:

Insulation, Heating, and Light

For very cold climates, a greenhouse heater is a must. This ensures your plants won’t get too cold once the sun goes down.

Bubble wrap is one of the best greenhouse insulators.

Look for special horticultural bubble wrap with large bubbles. Those big air pockets are what keep the heat in. If you can’t find it, regular bubble wrap also works, just not quite as well.

Grow lights are good for ensuring any sun-loving plants have plenty of light, even on short winter days.

Seed Starting Equipment

Basic seed-starting equipment makes starting plants in your greenhouse simple and fast.

At a minimum, you’ll want seed trays or other small containers, a good seed starting mix, and something to water with.

This seed starting kit has everything you need to get started.

Seeds are available online any time of year from retailers like Hoss ToolsTrue Leaf Market, and even Amazon. Save extra seeds for next year’s garden.

Plants

If you’d rather not start from seed, you can purchase plants in late summer to early fall from garden centers and nurseries.

Plants are harder to find during the winter, so try to purchase them early for the best selection.

How to Maintain a Winter Greenhouse

Just like with a traditional garden, regular maintenance is important to keep plants healthy and growing in a winter greenhouse.

Keep your plants well-watered, and watch out for any signs of distress or disease. Fertilize plants regularly and make sure to move plants up into larger containers as they grow.

On warm, sunny days, don’t let the greenhouse get too hot. There needs to be a way to let excess hot air out so the balmy greenhouse doesn’t turn into an oven.

Another thing to watch out for is snow. If you get regular or heavy snow, make sure it’s not accumulating too much on top of the greenhouse. For one, you want sunlight to get through and snow can block a lot of light.

Another important reason is that snow can get very heavy, very fast. If your structure isn’t designed to withstand the weight of snow piled up, too much snow is a recipe for disaster!

winter greenhouse

Time to Build a Winter Greenhouse

You can’t beat the taste of fresh homegrown vegetables. With a winter greenhouse, you’ll be enjoying that farm-fresh flavor even during the coldest days of the year.

For more tips on getting ready for winter, check out this post on How to Prepare for a Winter Storm.