Greenhouses – the joy of gardening under glass

If you prefer to grow your own vegetables and have space in the garden, it is worth buying a greenhouse.
This allows the harvest season to be extended significantly. Starting with growing young plants or driving herbs and cut flowers. Sometimes it is even possible to grow vegetables, strawberries and herbs there all year round. Finally, you can also overwinter potted plants there or plants such as Collect cacti, bonsai and palm trees in it.

Different models

The most beautiful version is made of glass, is robust and very weather-resistant (if you disregard the hail). The light transmission is optimal. In addition: noble greenhouses in the style of Victorian orangeries are also something for the eye. Big enough, they can even serve as a sheltered seat.
The most common variant now consists of double wall sheets. They are more shatterproof than glass and are almost as translucent. They are also easy to clean and good at insulating.
For the beginning or in a small garden, a greenhouse made of foil can also do. It’s inexpensive and works well for growing tomatoes and other warmth-loving vegetables.
Depending on the strength and design, this inexpensive version will last five to ten years. If the film is damaged, it can be repaired relatively easily. In a storm, however, the light foil houses quickly reach their limits, as the fastenings are exposed to strong tensile forces.

Size and location

One thing is certain: the more spacious the room, the more balanced the climate. For hobby gardeners who only want a few vegetables and a few summer flowers, a small model with an area of ​​three to eight square meters is sufficient. A ten to twelve square meter area is sufficient for the needs of a family of four. Warmth-loving vegetables such as tomatoes, cucumbers or peppers are recommended here. The height of the greenhouse is an additional criterion. The minimum distance between plants and roof should be min. 30 centimeters, otherwise the plants will suffocate. A sufficiently large house with ten to twelve square meters of floor space is also recommended for wintering potted plants. A width of at least two meters provides sufficient freedom of movement.
And where should it go? Seedlings need brightness and uniform temperatures. A sunny to partially shaded location is therefore recommended – this also saves heating costs in winter. Greenhouses don’t necessarily have to be free-standing. There are also models that lean against the house wall. A small version even has space on a balcony.

Aluminum or wood profiles

Thanks to the light metal, aluminum greenhouses have a very long shelf life.
Wood is a very inexpensive, easy-to-use building material. But also more maintenance and care intensive than aluminum. Above all, tropical hardwoods such as teak are used, and occasionally red cedar. All other types of wood suffer quickly from the warm, humid climate.


Whether the greenhouse needs to be heated at all depends on the use. If Mediterranean potted plants are to overwinter in it and young plants are grown from the end of February, a so-called cold house is sufficient. A heater is only required for the frost-proof wintering of tropical and subtropical plants or for year-round vegetable cultivation.
When buying, the size of the house, the fuel price and maintenance costs are decisive. Space-saving electric or propane gas heaters have proven themselves for hobby greenhouses. The heat sources should be set up in the greenhouse so that they are distributed as evenly as possible in the room. Plants that are too close together impede ventilation. The plants should also not come too close to the heater. A so-called frost guard is recommended to keep the greenhouse frost-free. This switches on automatically when the temperature in the greenhouse falls below a certain threshold.


In glass houses with aluminum profiles, there is an insulating layer made of wood or plastic between the inner and outer profile. So there are no cold bridges.
In unheated greenhouses, a highly translucent bubble wrap, also called bubble wrap, should be attached directly to the panes for wintering Mediterranean potted plants.

Building permit

In general, small greenhouses do not require a permit. The size of the so-called enclosed space is essential. This is the total internal volume of the building in cubic meters. The fact whether the greenhouse is connected to supply lines with gas, water and electricity can also play a role. Information on this is available from the responsible building authority. Usually a minimum distance of three meters to the neighboring property must be observed. Since lean-to greenhouses are often considered an extension of living space, a building permit is usually required in these cases. Exceptions apply to listed buildings.

Air conditioning

Good air circulation is important to contain disease and pests. That is why a greenhouse has to be ventilated regularly via a skylight or an open door. This also serves to harden the plants and avoid heat build-up.
Shading reduces the amount of incident sunlight and thus keeps the temperature inside low.

For larger models, shade can be provided in spring with shading paint. This is applied to the roofing of the greenhouse. In autumn, however, the whole thing has to be down again if the house is to be used in winter.
In contrast, aluminum slats are permanent. They are controlled manually or via photocells and react quickly to changes in lighting conditions. The lamellar variant is not cheap and is therefore primarily recommended for sensitive plants. For small greenhouses, a special shading net is sufficient that is stretched over the outside of the greenhouse.

Climbing plants can be an inexpensive and attractive shade. However, you should keep them in check, otherwise they will darken the greenhouse too much. In order to prevent the panes from becoming algae, a trellis with some distance from the greenhouse helps.

The price

The costs depend on the size, the material (wooden or aluminum frame, foil, glass or plastic panes) and the equipment. Small foil greenhouses with a size of six square meters are available for as little as 100 dollars. For a more stable greenhouse with an aluminum frame and glass or double wall sheets of the same size, you have to calculate with 400 to 500 dollars. Anyone who dreams of an English greenhouse with a brick base can easily find it with several thousand dollars. There are also costs for a foundation. As always, there is no upper limit here either.

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