Make your sunroom into a greenhouse! [Easy checklist]

Turning your sunroom into a greenhouse is a great idea but a lot can go wrong. You’ll need to establish all of the right conditions for your plants to thrive.  These nine steps will make your greenhouse a success.

A sunroom greenhouse with plants, light and an empty chair.

1. Get enough light

Every gardener knows that proper light is essential for plants.  Even though sunrooms are made out of glass, they may get less light than you think. If you plan to use yours as a greenhouse, make a careful observation of how much sunlight it gets.

Sunrooms on the south and west sides of the house will generally get the most sun.  If your sunroom faces north, you may have to get by with only growing very low-light plants.  You can also always supplement your light with grow lamps which are especially good for cultivating seedlings in the early spring.

Make sure to check for anything that might block the light to your sunroom. Cutting back some shrubs or trees that are blocking the light might do wonders for your new greenhouse.

2. Not too hot

All that sunshine can heat things up dramatically in the summer. There are several ways you can keep your plants from overheating.  

First, during the summer use blinds or curtains to block the worst of the afternoon sun.  

Second, get some airflow by opening the windows or doors and adding a fan. A ceiling fan can also help keep things cool. 

Third, consider leaving the doors open to your house to share your air-conditioning with your new greenhouse.

Finally, if you live in a hot climate you might want to avoid using your sunroom as a greenhouse during the summer months.  Consider putting most of your plants in portable pots so you can move them outside during the summer and keep them protected during the winter.

3. Not too cold

Winter nights can kill plants as easily as a hot summer afternoon. Because the sunroom is connected to the house, it should automatically avoid the worst of the winter temperature.

A well-sealed and insulated sunroom is the first step. If there are leaks, broken seals, or anything else that can let the warm air out fix those first.  Caulk, weather-stripping, or even tape can help.

On the coldest nights, leave the door between your sunroom and house open to let the warm air protect your plants from frost.

You can add stylish insulation by hanging some thick curtains in front of the glass windows.

If things still get too cold, you could also add a small space heater to take the chill off.

4. Pick the right plants

Not all plants will do equally well in a sunroom greenhouse. Plants that require less light and moderate temperatures will do best.  Here are a few suggestions. 

  • Low-light vegetables:  Brassicas like kale, turnips, and bok Choi can do well over the winter months in your sunroom. Lettuce, spinach, and microgreens are good bets as well.
  • Herbs: These hardy plants can grow great in a sunroom all year round. Mint, thyme, sage, and oregano are perennial species that should thrive year-round in your sunroom.  Basil, cilantro, dill, and parsley are annuals that you can plant in the winter and harvest all through early spring.
  • Ornamentals: Bamboo, spider-plants, and fiddle-leaf-figs can all do great year-round in your sunroom.  Almost anything that grows well indoors should thrive with the added light of your sunroom.
  • Seedlings: A sunroom is a great place to house seedlings in the early spring.  Especially if you can add a grow-light.  Getting those tomato and pepper seedlings ready early in the spring can give your outdoor garden a jump-start.

5. Use pots and planting boxes

Plants need dirt! There are many stylish and practical ways to give your plants home in your sunroom.

The simplest thing to do is use large grow boxes and pots placed on low tables or benches around the edge of your sunroom.  This is a flexible and cheap arrangement that still should let you get a lot of growing space.

Use large pots for trees and any perennials that you would like to move outside in the summer. 

Hanging pots can easily expand your growing space without taking up too much room in a small sunroom. 

A plant in a hanging pot.
Hanging pots maximize floor and growing space.

To get the most out of your space, use a raised indoor planter box like this one from Amazon.

If you have the budget and the skill, you can construct your own raised beds around the outside edge of the sunroom to get a huge amount of year-round growing space.

6. Establish humidity 

Indoor air can be a lot dryer than what plants would prefer. Consider adding a humidifier to your sunroom to keep things moist.

Leaving open containers or trays of water around can also help stabilize temperatures and keep things humid.

For a stylish touch consider an indoor fountain or water feature.

7. Get the air moving

Stagnant air makes plants more likely to contract diseases. When you can, open a window or door to give your plants a breath. 

In the winter months, make sure you have a fan to keep things circulating well.

8. Blend into your living space

Just because you want to use your sunroom as a greenhouse does not mean it cannot still be a functional room in your house.

Add a small sofa or a few chairs so you can enjoy your new greenhouse. 

9. Get started!

Using your sunroom as a greenhouse is a great idea. As long as you properly address all the needs of your plants, you can easily build a peaceful and productive oasis attached directly to your home. So get out your planters and take a step towards year-round greenery and produce.

Common Questions

Is a sunroom the same as a greenhouse?

A sunroom is not the same as a greenhouse.  Both of them are buildings constructed primarily of glass, but they differ in purpose and placement.  A sunroom is attached to the house and is used as an expanded living space.  A greenhouse is generally detached and is primarily for growing plants. Some greenhouses are also used for the commercial production of vegetables and seedlings.

Can you grow vegetables in a sunroom

Yes! As long as your plants have sufficient sunlight, water, airflow, and a reasonable temperature. Low-light vegetables will do best.  Brassica species like kale, turnips and bok choi should do well. Leafy greens like spinach and lettuce are also a good fit. Finally, hardy herbs like sage, mint, and thyme can add spice and color all year long.