A greenhouse allows you to extend your growing season, produce more of the flowers and produce you love, and protect those plants that are particularly sensitive. However, when run inefficiently, it can be expensive to operate, especially during the times of the year when it requires more work to replicate optimal growing conditions. Protect your plants while saving energy (and money) with these tips:

Consider Level of Use

Are you using your greenhouse to grow things all year long or simply to mimic a tropical environment? How much you intend to use the structure during certain times of the year will help guide the improvements you’d like to make to it.

Maintain Temperature

Consider applying a double layer of polyethylene to your greenhouse to help maintain a consistent temperature within and reduce your heating costs by as much as 60 percent. Additionally, add sheets of bubble wrap or another layer of plastic over the existing panes to improve insulation.

Address Any Air Leaks

Place weather stripping around the windows, vents, and doors. If your greenhouse is an older model, you'll want to ensure that its doors and windows are properly sealing to prevent heat loss. For the same reason, you'll also want to check the areas around your fans. If you can see light peeking through cracks around your fan, you can bet that heat is escaping from there, too. Consider installing fan covers over the fans when they aren’t in use.

Plant Windbreaks

Lay down a few trees or large hedges or place a fence along the north side of your greenhouse to prevent cold north winds from reducing heat within. Take it a step further by ensuring that the north-facing side of your greenhouse is properly insulated.

Eliminate Waste

The easiest way to eliminate waste is to make sure your greenhouse' systems are running smoothly. If you’re using timers for heating or ventilation, set them according to seasonal needs and the needs of the plants you’re protecting. That way, you’ll never be using more heat than you absolutely need.


If you’ve been operating your greenhouse for several years, consider upgrading to a high-efficiency model to improve overall efficiency by at least five percent. Just make sure your system is always running near its full load.

While you’re at it, you should also upgrade your lighting and fans to high-efficiency models. For lights, opt for compact or tubular fluorescent or metal halide fixtures. Once you have updated your lights, be sure to keep them clean to maintain maximum efficiency. The same is true for your fans. Always make sure that your fans have a high ventilation-efficiency ratio.

Don’t Forget the Floor

If your greenhouse is still in the planning stages, remember to insulate its floor by installing insulation about two feet below the soil line. This will also prevent heat from escaping.

Install Energy Curtains

If you have a medium to a large-scale operation, energy curtains are sure to help you save money in the winter and run things more efficiently in the summer. In the winter months, energy curtains help retain heat inside the greenhouse. In the summer, the curtains diffuse the light that comes in and help maintain a constant internal temperature.

Utilize Passive Solar Techniques

Passive solar helps capture more light and heat without relying on mechanical systems.

If you live in the northern climates, consider utilizing passive solar building techniques when constructing your greenhouse. Insulate the north-facing wall with foam insulation to prevent heat from escaping. Angle your south-facing glazed windows to help them capture more light.

Place water barrels throughout the greenhouse in the winter. These barrels will collect heat throughout the day, which will radiate throughout the cooler nights. Line them along the north side of the greenhouse.

What If You’re Not Using Your Greenhouse As Much During The Summer?

If you have a large outdoor garden, you may find you’re not using your greenhouse as much in the summer. If that’s the case, use this time as an opportunity to insulate and update your greenhouse to prepare for the cooler fall and winter months.

Inspect your current systems to ensure they’re running well and efficiently. This may be the time to upgrade any outdated systems. If you can’t replace it, try to repair it.

Plan for the changes you need to make to get your greenhouse up to speed before the end of the summer. Write down all the changes you’d like to make. Also, consider creating a growing plan for the cooler months by tentatively deciding where to place the plants you’d like to grow.

Clean out every surface of your greenhouse, including the lights, fans, and glass. Replace burned out bulbs and broken panes, make repairs to all systems, and install insulation.

Remember, a bit of care and preparation now will make it easier to utilize your greenhouse later on, which may also help you save money on your monthly bills.