The Content Of The Article:
- Greenhouse Types
- Glass or plastic discs
- Aluminum or wooden profiles
- The ideal size
- Air conditioning
- Interior of the greenhouse
- building permit
- The location for the greenhouse
- The foundation
Depending on location and use, there are different types of greenhouses. They can be divided into freestanding greenhouses, residential greenhouses and film tunnels.
The classic variant is the free-standing greenhouse. For example, the saddleback greenhouse is one of them. It has a rectangular floor plan, vertical walls and - as the name suggests - a pitched roof. The so-called earth house represents another variant. It is sunk into the ground, whereby the structure is lower. The earth house is often used for the cultivation of small plants such as cacti. When purchasing, however, you should immediately calculate the time-consuming earthworks. It is also not the ideal choice for regions with high groundwater levels.
Greenhouses with sloping side walls are called Dutch Light Houses. This design has the advantage that even in winter enough light falls through the sloping roof. In relation to the floor area, however, this house offers less usable space.
Leaning greenhouses are halved greenhouses, which are grown on a building wall. Advantages are the low purchase price and the energy savings, because the wall stores the heat well. In addition, there are still small balcony greenhouses, which resemble the form of the narrow landing greenhouse and find space on the balcony or terrace.
Greenhouses in the style of Victorian orangery are first and foremost a distinguished eye-catcher, which is why clear glass is preferred. They are also great as a sheltered seat between sensitive potted plants usable
Foliated tunnels protect the plants from light frost and therefore allow an extension of the culture time. In sunshine, the air heats up under the film, so that the temperatures in the tunnel are a few degrees above the outside temperatures. The sowing can therefore take place earlier than in the field. The tunnel also provides protection from moisture, preventing the spread of disease. Film tunnels are more or less mobile depending on their size and design - so they can be set up where they are needed. The heating of a film tunnel or foil greenhouse, however, does not make sense, since the energy losses due to the thin film are very high.
Glass or plastic discs
The covering material of a greenhouse has a considerable influence on the thermal insulation and plant growth. It usually consists of glass or plastic. Conventional glass lets most light through, but the material is very vulnerable to breakage - for example, by hail or the stem end of a cultivator in the soil tillage. The directly incident sunlight can also cause so-called blank glass to burns on the plants. Therefore, rough-surfaced glass is often used because it produces a less aggressive stray light. A good thermal insulation is only possible by installing a very expensive double glazing. Therefore, single glass is only recommended for greenhouses, which do not need to be heated additionally.
Plastic has gained in popularity in recent years. Resistant to break-proof multiwall sheets made of acrylic glass, which is mainly known under the brand name Plexiglas. Acrylic glass has a similar high light transmission as real glass and is the most durable plastic glass. It does not let through UV light and thus reduces leaf damage caused by sunburn. Only after many years does the light transmittance slowly diminish. It is also more sensitive to scratching than real glass and priced a bit higher. Thanks to a special coating, a special version called Alltop has the advantage that the condensation of the plants runs as a film of water. Thus, burns on the plants are largely excluded.
A foil greenhouse is inexpensive and well suited for growing tomatoes and other heat-loving vegetables
An inexpensive solution is polycarbonate web plates. They are often used for covering cheap greenhouses and are very light. Their translucency is about 85 percent when new compared to real glass, but it can be quickly reduced by aging processes. In addition, they become more fragile over time as the plasticizers volatilize.
Foil is the least expensive material and lasts five to ten years, depending on the thickness and design. If cracks occur, they can be covered relatively well with thicker foils, but at the expense of the already relatively low light transmission. The flexibility has disadvantages, especially in the case of a storm, because strong tensile forces can occur at the fastenings.
Aluminum or wooden profiles
A big advantage of aluminum greenhouses is the very long life of the light metal.By the reaction of aluminum with oxygen, the metal develops a dark gray layer - the so-called patina. It serves as a permanent protection against corrosion.
Wood is a very inexpensive, easy-to-use building material. However, you must make some compromises in terms of durability and technical features. The maintenance and care work is more complex than aluminum. If you still decide to use wood, pay attention to high-quality raw material. In the retail trade, there are occasional greenhouses from Red Cedar. It is the very light and durable wood of the giant tree of life (Thuja plicata). As an alternative, especially tropical hardwoods such as teak come into question. All other wood species decompose quite quickly in the humid greenhouse climate.
The ideal size
Purpose, land size and acquisition and maintenance costs decide on the size of your greenhouse. Classic greenhouse models with pitched roof are available for private use in sizes from 2.50 to over 50 square meters of floor space. Hobby gardeners, who only prefer a few vegetables and a few summer flowers, can usually cope with a small model with a surface area of three to eight square meters. Equipped with upright and hanging shelves serves well for this purpose. An area of ten to twelve square meters is sufficient to supply a family of four with heat-loving vegetables such as tomatoes, cucumbers or peppers. If you also want to use the greenhouse as a growing area for various ornamental plants, fifteen to eighteen square meters are recommended. The height of the greenhouse also plays a role in the vegetable culture: Cucumber plants are cut early, this has a negative impact on the crop yield. The minimum distance between plants and roof should be 30 centimeters, otherwise the plants will suffocate.
Also for the hibernation of potted plants, a sufficiently large house with ten to twelve square meters of floor space is recommended. Restrictive conditions favor pest infestation and fungal diseases in winter quarters. In addition, the greenhouse should be at least two meters wide, so that you have enough freedom of movement during tillage and plant care.
The heating ensures that the temperatures in a greenhouse do not fall below zero degrees Celsius. Whether you need to heat your greenhouse at all depends on its use. If you want to overwinter Mediterranean potted plants such as olives or oleanders in it and from the end of February want to attract young plants, a so-called Kalthaus is completely sufficient. You need a heating system especially for the frost-proof hibernation of tropical and some subtropical plants as well as for the year-round vegetable culture.
A mobile propane gas heater is completely sufficient to keep a larger hobby greenhouse frost-free in winter
Which heating system you choose for your greenhouse depends on various factors such as fuel price and maintenance. For greenhouses, space-saving electric or propane gas heaters have proven their worth. These heat sources are placed in the greenhouse so that the most even distribution of heat in the room takes place. Too close to each other plants impede a uniform heat supply. Also, do not place the plants in the immediate vicinity of a heater. If it's just a question of keeping the greenhouse frost-free, you can get out with a so-called frost guard. This is a small, low-power heater that automatically turns on when the temperature in the greenhouse drops below a defined threshold.
Leaning greenhouses can usually be connected to the existing house heating system. Particularly important here is the sufficient thermal insulation of the supply pipes. Since individual ovens have a high maintenance and can also affect the taste of lettuce and vegetables, they are recommended only for ornamental plants.
A good insulation is essential to use a greenhouse even in the winter months without high heating costs. We therefore recommend high-quality glass houses with thermally separated aluminum profiles: between the inner and outer profile, which encloses the glass elements, there is an insulating layer of wood or plastic. In this construction method, which is also common in winter horticulture, there are no so-called cold bridges.
Additional insulation is particularly useful in unheated glasshouses for wintering Mediterranean potted plants. The ideal material is a highly translucent bubble wrap, also called bubble wrap. The price of the UV-stable film is around three euros per square meter. As holding systems serve metal pins, which are attached with suction cups or plastic plates directly on the discs.
Greenhouses with onion-shaped roofs such as the "Riga S" model do not match the classic design.But they keep the heat very well and guarantee good light scattering for optimal growth
To prevent sunbeams from continuously affecting the plants and causing damage, you can reduce the amount of light by using shading. Even with insufficient ventilation, excessive heat development can be prevented in this way. An externally applied shading reduces the amount of incident sunlight. The temperature is lowered more effectively than shading inside the house.
Shading paint is a special color that is applied to the covering of the greenhouse. The inexpensive color can be purchased from a garden retailer or even made from water and whiting or wheat flour. Since the color is applied in the spring and must be removed in the fall, when the greenhouse is used in the winter, the application is associated with a high workload. Shading paint is particularly suitable for large greenhouses and plants with low light requirements. For small greenhouses, it is usually easier to put a special shading net over the glasshouse from the outside. However, it must be well secured so that the wind can not take it.
As a permanent shading method, aluminum fins are suitable. They are controlled manually or via photocells. Accordingly, the shade responds quickly to changes in lighting conditions. The lamellas are especially recommended for valuable and sensitive plants as well as in the conservatory. Their disadvantage is the high price.
In the case of unheated greenhouses, insulation with bubble wrap makes sense in the autumn, for example for hibernating potted plants
Climber plants serve as an inexpensive and attractive shade. However, you can also darken the greenhouse too much. High-ranking plants also clog gutters and can lead to the algae of the discs. Therefore, it is better to attach a trellis with some distance to the greenhouse. Occasionally it is also recommended to simply place the greenhouse under a large tree. But there is a certain risk, because during a storm, branches can break out and damage the glass house.
Effective ventilation is best achieved through folding windows in the greenhouse roof. They are standard on all higher quality greenhouses. A roof ventilation compared to the side ventilation, for example through the greenhouse door has the great advantage that the hot, rising air can escape much faster. Highly recommended are also automatic window opener. They contain a liquid that expands when heated, and then raise the skylights like small hydraulic cylinders.
Interior of the greenhouse
Paths and footsteps are useful interiors in the greenhouse. They allow easy walking between the rows of plants. Suitable are simply concrete slabs. On the other hand, it is not recommended to use washed-out concrete slabs, as these can deteriorate and become slippery in a warm, humid climate. Also not recommended is wood.
The simplest and most sensible development is a central way out of concrete slabs
Plant beds can be created at ground level or as raised and bank beds. The higher versions are easy on the back and simplify the care work. Cultural tables or racks are needed above all for setting up and petting young plants. But also sowing bowls and crates as well as pots and utensils find their place here. Pay attention to the stability of the tables. Tables with a depth of 80 centimeters, a width of between one and two meters and a height of at least one meter have proven to be the optimal size. If your greenhouse does not have enough space for a work table, you can use inexpensive consoles or hanging culture tables.
On shelves young plants can be stored in the greenhouse to save space
In general, small greenhouses are permit-free. As a criterion of whether a building permit is necessary, in most state building regulations the size of the so-called enclosed space applies. This is the total interior volume of the building in cubic meters. The fact that the greenhouse is connected to gas, water and electricity supply lines can also play a role.
Before purchasing the desired greenhouse, please inform your local building authority about possible regulations. In general, it can be said that - depending on the development plan - a minimum distance of three meters to the neighboring property must be maintained. As awning greenhouses are often considered as an extension of the living space, they usually always require a building permit. Here the authorities check the stability and the fire protection of the desired construction. In listed buildings residential buildings are often not approved.
The location for the greenhouse
Since a greenhouse must provide optimum light and warmth to the plants in it, the location should be sunny and sheltered from the wind.Avoid a place under trees and near high hedges or walls. Optimal is an alignment of the greenhouse with the ridge in east-west direction. However, this is not a must, because in the north-south direction, the light is still sufficient.
If possible, you should set up your greenhouse near your home. So you do not need long supply lines for water and electricity. In addition, such a location offers the opportunity to reap a few fresh tomatoes before cooking.
For the stability and stability of larger greenhouses, a 80 centimeter deep strip foundation made of concrete and a flat base frame are indispensable. Make sure that the frame profile rests well on the foundation everywhere. In heavy greenhouses in particular, insufficient foundation can cause tensions in the glazing and lead to cracks. In addition, a poorly aligned base frame complicates the further structure, because the profiles then no longer fit together properly.
Greenhouses with plinth walls are very popular in England
Sometimes a low brick wall is built on the foundation. This makes sense to compensate for unevenness on the foundation surface and to increase the overall construction somewhat. Tip: You can also extend the base walls with correspondingly created foundations to raised beds. So that the floor heat does not escape during the cold season, you should insulate the foundation and - in raised beds - also the base wall of your greenhouse on the inside with six to eight centimeters thick Styrodur plates. This is especially useful if you want to heat your greenhouse in winter.