To support a garden, the soil in a greenhouse or a greenhouse itself should ideally be 37°F or higher. Reaching this temperature during the coldest months of the year is more challenging, but it is still feasible. There are other ways to heat your greenhouse besides installing a heater and insulating it. To find out more about heating a greenhouse for winter gardening so you can always have fresh vegetables, keep reading.
Five strategies to warm a greenhouse for gardening in the winter:
1. Install more insulation
2. Include thermal mass
3. Create compost
4. Install a heating mechanism
5. Keep animals
FAQs
1. Install more insulation
A greenhouse is passively heated by insulation; increasing insulation reduces heat loss instead of adding additional heat. You might concentrate on insulating the soil or specific plants in addition to the greenhouse’s overall structure. You don’t need to insulate or heat the rest of the greenhouse as long as the plants are at the proper temperature.
You can insulate your plants, soil, or greenhouse in the following ways:
- Make use of bubble wrap.
- Recycle leaves from the fall.
- Put in some mulch.
- Keep your plants covered.
Make use of bubble wrap
You can insulate your greenhouse if you have a lot of bubble wrap hanging around. Just use bubble wrap to cover the greenhouse’s interior walls. Therefore, save the questionable quantity of bubble wrap that comes with your Amazon shipment for the winter.
Recycle leaves from the fall
Lacking bubble wrap? No issue! Homeowners like you can use fallen leaves as an inexpensive, even free, substitute. You may repurpose fall leaf bags as insulation by piling them against the walls of your greenhouse.
Put in some mulch
The insulation mulch offers your soil is just one of its many advantages. Throughout the winter months, mulch keeps the earth (and your plants) warm.
Additionally, don’t believe that expensive mulch is necessary. Even in your own backyard, you can obtain free mulch made from grass clippings, fallen leaves, or used paper goods.
Keep your plants covered
One approach to keep your plants safe from freezing temperatures is to cover them. Cloches, row covers (usually made of clear plastic), or horticultural fleece (sometimes called gardening fleece) can be used to cover greenhouse plants. Old milk containers, repurposed drink bottles, or even miniature greenhouses (hotboxes) might be used for the latter.
2. Include thermal mass
The capacity of a material to absorb, hold, and release thermal energy—such as solar heat—is known as thermal mass. Simply adding more materials with a high thermal mass will increase the thermal mass of your greenhouse. These substances act as heat sinks, absorbing the heat from the sun in the morning and releasing it at night.
Materials with high thermal mass that are readily available to homeowners include water, soil, clay, stone, bricks, and ceramics.
You can include them into your greenhouse in the following ways:
- Put water tanks or barrels in the greenhouse’s corners and along the north wall; black tanks or barrels will absorb the most heat. Even tiny water containers can be useful if you don’t have a lot of room.
- Add borders and brick or stone pathways. This adds style in addition to thermal bulk.
- Keep additional soil bags in your greenhouse.
3. Compost
As organic matter decomposes, heat is released. By producing compost indoors, you can keep your greenhouse warm throughout the winter and, as a bonus, receive black gold for your garden. Making a hotbed is a more practical and visually appealing solution than just digging a hole and creating a compost pile.
A hotbed is a raised garden bed that is mostly filled with composting materials and covered with a growing media (like soil) to initiate seedlings in the winter. Maintain a 3:1 compost to soil ratio and try to create a hotbed that is at least 20 to 30 cm deep. A healthy proportion of greens to browns is also necessary. If you want even more heat, you may cover your hotbox with a row cover, cloche, or even an old window pane.
You can just use a compost container if you don’t want to create anything. For inspiration, look through our selection of the top compost bins.
4. Install a heating system
The most reliable method of heating a greenhouse is to install a heating system. Fuel comes from a variety of sources, including coal, wood, electricity, kerosene, natural gas, propane, and renewable energy sources like solar.
These kinds of heating systems can be powered by them:
- An electric heater for a room
- Heating system with hot water
- heater for the unit
- Heater that radiates
- Ground-to-air heating system for a stove
- Make your own little heater
To distribute the heat around, you’ll need airflow, so make sure it’s not trapped in one spot. Failure to do so could result in moisture accumulation and the growth of mold in your greenhouse.
It is preferable to install certain heating systems prior to assembling your greenhouse. If not, you might have to demolish a few sections of the building to make room for the heating system.
Please refer to our list of the top greenhouse heaters currently on the market if you would like some recommendations on what to purchase.
An electric heater for a room
Electric room warmers run on electricity, as their name implies. Some of them are energy-efficient and fairly upscale. Some electric heaters, for instance, have thermostats built right in, and they can be set to only turn on when the temperature falls below a specific threshold. Some even have fans built right in.
Since they don’t emit any pollutants, electric heaters are among the superior heating solutions when compared to gas heaters. They don’t need to vent as a result.
Heating system with hot water
Boilers and pipes make up hot water systems. Boiling hot water and pumping it through a network of pipes throughout the building is how they warm greenhouses. Additionally, they have the ability to pump steam rather than hot water, which is how Korean greenhouses were heated in the fifteenth century.
Using solar water heaters in place of a conventional boiler is one choice you might investigate. In this manner, venting won’t be necessary for this kind of system.
Heater for the unit
An independent heating system without ducts is called a unit heater. A range of fuel sources can power unit heaters, which can be vented or unvented. They progressively convert cold greenhouse hair into warm air in both commercial and home greenhouses.
However, because they require oxygen to operate, you will need to use caution when utilizing one of these. Additionally, your plants require oxygen, and you don’t want the heater to drain them of it.
Heater that radiates
Radiant heating systems, as opposed to unit heaters, use heat radiation to warm greenhouses. In other words, they don’t circulate air; they just heat the immediate vicinity. Because they don’t require fans, radiant heaters are quieter than their convection counterparts.
They do, however, have drawbacks. You must be careful where you put radiant heaters because they work best in limited areas; put them close to the plants that require the most heat. Additionally, they cost more.
The stove
If you have a consistent supply of wood for fuel, wood-burning stoves are a heating method worth investigating. If this is the case, they can ultimately save you a significant amount of money. You must properly set these up, though. Wood stoves must be vented since they are a fire hazard.
If you decide to purchase this heating system, it is advised that you purchase a thermometer to monitor the temperature in your greenhouse.
System of ground-to-air heating
The soil heats the air below ground in a ground-to-air or geothermal heating system. The soil’s high thermal mass allows it to absorb a lot of heat from the sun in addition to having thermal energy of its own. Therefore, once the chilly night arrives, you can heat air in subterranean pipes to pump back into the greenhouse.
Make your own little heater
What kind of heater is suitable for a tiny greenhouse? Actually, you can make your own tiny space heater using a few ceramic or terracotta pots and candles. Here’s a guide from Gardening for Beginners on how to create your own candle-powered heater:
5. Keep animals
Have you ever considered adding some fresh eggs to your garden vegetables? If you’ve considered keeping hens, you could want to do so in a coop next to your greenhouse or in your own greenhouse. A greenhouse can be heated by the body heat produced by warm-blooded animals.
FAQs pertaining to greenhouse heating
Can it get too hot in a greenhouse?
It can, really. Not only are you uncomfortable around 90°F, but so are your plants. Although a minimum temperature of 37°F is necessary to support delicate plants, 45°F to 50°F is optimum for the best growth. Although unheated greenhouses can prolong the growing season, they probably won’t be sufficient to enable gardening throughout the year in a cold environment.
If you’re attempting to produce exotic plants, such as tropical plants, that require a particular temperature to flourish, ignore this. If so, you’ll need to heat your greenhouse in accordance with the conditions that are advised for your plants’ growth.
For the finest winter sun, where should your greenhouse be built?
If you’re building your own greenhouse or hiring someone to do it for you, you should make sure it faces south. The winter sun in the northern hemisphere remains on the southern side all day. In order to minimize the need for heating, make sure your greenhouse receives as much direct sunshine as possible during the winter months.
What is the price of building a greenhouse?
A greenhouse, with heating and insulation, typically costs about $11,000. That is, if you get it installed by a contractor. Building your own greenhouse is an option if you want to save money. Another option is to use one of the top greenhouse kits rather than beginning from scratch. Even though these kits can be costly, they are still less expensive than employing a contractor.
Are you prepared for winter in your garden?
Whether your garden is outside or in a greenhouse, getting it ready for winter requires time and work that you may not have. Why not employ a professional gardener to look after your flowers and other vegetation instead of you doing it yourself? Lawn Love can put you in touch with local experts who can handle all of your landscaping, lawn care, and gardening requirements. Get a quick, easy, and free quote or hire a gardener with Lawn Love right now.