Winterizing Your Greenhouse for Heat Retention

Who’s ready for some winter gardening? As cooler temperatures approach, many growers aim to just keep their plants alive through harsher conditions. However, with some careful planning, some energy-saving tactics, and a few products you may already have on hand, you can have a thriving winter greenhouse this year!

Many gardeners are now packing away their shade cloth until warmer weather is near. Letting every last bit of the weakening sunshine into their greenhouse or winter garden is foremost in most growers’ minds, so why keep your shade cloth in place? Depending on what type of shade cloth you have, it can act as a thermal heat curtain in winter. That’s a big plus when it comes to keeping valuable heat inside your growing space!

Aluminet shade cloth is excellent at keeping the heat that your greenhouse has collected from the sun during the daytime inside at night. Hung inside your greenhouse, the aluminum filament preserves heat, and can increase the efficiency of your heater by up to 30%! Many growers will open or remove the shade during sunny days, then close it during the night. This method makes the most of the available sunlight during the day and helps to trap the heat inside when the evening comes.

Aluminet is also successful in reflecting back the invisible heat radiation given off by plants and the greenhouse floor. This heat energy gathers during the day and releases at night in all objects. Traditional black or colored shade cloth can also slow this heat loss but is not as effective as Aluminet in reflecting this heat back to the leaves of the plant.

Shorter days and less light may mean that you want to add supplemental lighting to your greenhouse. If you don’t already have growing lamps, special consideration for winter is heat output. LED lighting, while very cost-effective to operate, can be expensive to invest in and produces very little heat. During winter, metal halide (MH), high-intensity fluorescent (HIF), and high-pressure sodium (HPS) are good choices, due to the heat they produce, as well as the low cost to implement. You can read more about how to choose the best greenhouse lighting here:

Aluminet is also helpful in increasing the benefits of your lighting. The twisted woven strands of Aluminet reflect diffused light back in many directions from the source. This diffusion and reflection promote more vigorous growth in the lower branches, less stress on the leaves, and more even light distribution.

Your supplemental lighting and heating can also be more effectively used in your greenhouse with the addition of a specialized heat-retention curtain. A closed fabric for efficient heat retention, made from woven Polyethylene and Aluminum strips, can be an excellent investment to winterize your greenhouse. In addition to moderating daytime and nighttime temperatures, these curtains reduce shadows, control air movement, and cold spots, and add optimum light diffusion to your indoor crops. Call our experts today for a quote on this new and innovative item!

A natural way to lower your heating costs is by storing heat. Make use of planters filled with soil or even large closed containers of water. Both options store heat, providing you with even more ways to seal in warmer temperatures inside your greenhouse. Moving raised beds inside is a great way to both grow to store your warmth all through the coldest part of the year. It’s a great time to switch to winter-specific crops, which have less sunlight requirement! We have several blogs regarding winter crops, which you can read here: https://www.gothicarchgreenhouses.com/blog/2020-year-round-growing-guide/

Now is the time to do yearly maintenance checks on your greenhouse heater. Test your heater and thermostat, and try giving it a test run before you have to rely on it. Perform any needed maintenance and even stock up on key parts that may be needed. As part of your testing, check the accuracy of your thermostat to ensure all systems are functioning properly.

If you’ve not yet chosen a heater for your growing space, you’ll want to consider if electric, natural gas, or propane is the best option for you, as well as if your plants require a vented or non-vented heater option. If you need some guidance on this aspect of winterization, please call our offices! We are happy to help find the best option for your growing situation.

Last, our final winterizing recommendation is to always remember that investments you make today in the future of your garden can have results for many, many growing seasons to come. For some ideas on what to do today to ensure gardening success tomorrow, check out our blog from last year!

Thanks for reading today—we’ve had a long absence from posting, due to the many strains that 2020 and 2021 have brought. We’re pleased to be looking towards the future, and from all of us at Gothic Arch Greenhouses, HAPPY GROWING!