Setting up a DIY mini-greenhouse on a balcony or veranda

Remember: thermal insulation materials release accumulated moisture extremely poorly. If you install damp insulation, the space between the wall and the cladding will quickly become damp, which will lead to the appearance of mold. Before laying, organic materials must be treated with an antiseptic, otherwise, they will rot.

The type of thermal insulation determines the specifics of frame assembly. Each material behaves differently during operation. When working with them, it is necessary to strictly observe the technological installation rules.

• Loose insulation materials settle over time and form voids, reducing protection against cold. To have the possibility of adding more settling material, provide removable panels in the upper part of the cladding.
• Board insulation materials require precise adjustment of the frame. The distance between vertical posts must strictly correspond to the width of the boards.

To fasten board materials to the posts, two clamping bars are used. They are nailed along the entire length of the posts, forming grooves into which pre-cut ridges on the boards are inserted. The boards can also be attached to posts made of plywood or roofing steel. If you fill the opening between the posts with 2-3 boards, fix the joint with a vertical board embedded into the strapping. Maximum structural rigidity is provided by installing posts to the width of one board with subsequent careful sealing of the joints.

Installation and sealing of window units

For glazing a greenhouse, it is best to use wooden frames. Wood is characterized by low thermal conductivity, is easy to process, and allows for the creation of structures of any shape. The manufacturing of a window unit begins with precise measurements of the opening and preparing a drawing on drawing paper, which helps avoid errors during assembly.

Dried boards are used to assemble the frame. Before installation, their back side must be protected from moisture. The boards are covered with bitumen or lined with roofing felt, after which they are cut precisely to size.

• Cross-section of clamping bars — 20x30 mm
• Frame board thickness — at least 40 mm
• Wood humidity — 12-15%
• Number of roofing felt layers for lining — 2-3 layers
• Diameter of sealing cords — 30 and 40 mm

Special attention is paid to the tightness of the joints between the window unit and the concrete wall. There are several methods for insulating assembly seams. Gaps can be sealed with classic mixtures or by using modern materials.

1. Clean the surfaces of the window frames and concrete reveals of concrete drips, dirt, and dust.
2. Blow out the prepared surfaces with compressed air and treat with a primer.
3. Seal the gap using two synthetic cords.

If you use classic caulking, the gap can be filled with construction oakum and an alabaster or cement mortar. Another option is to caulk the cavities to their full depth with oakum soaked in cement mortar with gypsum paste. A combined method is also applied: fill the joint to 3/4 of the depth with dry antiseptic-treated oakum, and for the remaining 1/4 of the depth from the room side — with oakum soaked in alabaster milk or cement mortar. Sometimes the cavity is sealed with oakum in cement mortar and then poured over with mortar on expanded clay sand. Such methods ensure thermal protection, but their effectiveness depends entirely on the quality of the work performed.

When installing a window unit, it must be fixed in the design position with special wedges or bars installed at the bottom and on both sides of the unit. Mastic is introduced into the gap formed between the window unit frame and the wall panel reveal. Of course, the length of the cord must correspond to the perimeter. In this case, it is best to start caulking the gap with the cord from the top corner, without stretching the cord along the perimeter of the frame. Today, this method of sealing the cavity of the joint connection of the window unit to the wall has become quite popular. As practice shows, this option provides sufficiently high thermal insulation and performance qualities of the window slopes.

Sealing the gap with synthetic cords provides decent airtight properties for the joint, yet it does not offer complete hermetic sealing. In the future, the most widely used method for insulating the interface between a window unit and an exterior wall is expected to be the use of polyurethane foam. This polyurethane sealant is a foamed mass that forms directly in the cavity between the panel and the window frame.

Before installing the window unit into the opening, the connection points between the window frame and the panel rebate are sealed with a "Buteprol"-type mastic. Then, a resin is applied to the cavity between the window frame and the wall. As the resin hardens, wooden casings are installed on the inner side in the gap between the panel and the window frame, while the gap on the outer side is caulked with a solution. It is also possible to seal the gap with foamed polyurethane using a sealing mastic (without caulking the gap with a solution). The undeniable advantages of this method include the fact that foamed polyurethane has a low thermal conductivity coefficient and good elasticity, as well as adhesion to concrete and the wood of window units. Consequently, high thermal insulation qualities and complete hermetic sealing of the gap between the wall and the window unit are ensured.

After all this, the purchased window units, for which the frame was actually prepared, can be inserted into the prepared frame. Blocks with double, triple, and quadruple glazing are optimal for this purpose. To ensure the airtightness of the joints between the blocks and the general frame of a loggia or balcony, the same materials mentioned above are used. If the task is to insulate a veranda, then blocks with single glazing are replaced with blocks with double glazing, etc.

With minimal costs, one can set up greenhouses and orangeries of various modifications by adapting the south wall of the house for this purpose. Such greenhouses and orangeries will, among other things, provide additional heating for rooms through windows. AGROTECHNOLOGY OF PROTECTED GROUND SUBSTRATES AND MINERAL NUTRITION

Root-inhabiting environments in protected ground are called substrates (soils), as they differ from soils of natural origin.

Substrates are divided into proper soils — well-fertilized natural soils; soil mixtures, which consist of various components, mainly of organic origin with the addition of fertilizers; soil substitutes of organic origin (peat, straw, sawdust); and artificial substrates, which represent inert materials (gravel, expanded clay, sand, etc.).

The first three types of substrates are referred to as soil culture. Vegetable cultivation on artificial (inert) substrates, when plant nutrition is carried out through the absorption of nutrient solutions, is called hydroponics.

Nutrient substrates in greenhouses must be highly fertile with good air permeability, water-holding and absorption capacity, free from pathogens of diseases and pests and toxic substances, with a soil solution reaction (pH) for cucumber, lettuce, radish, onion of 6-7, celery, cauliflower — 6.5-7, tomato — 5.5-6.5. The best substrates contain 20-30% or more organic matter and 12-20% or more humus. The optimal bulk density of the substrate for cucumber is 0.5 g/cm3, for tomato — 0.8, for lettuce and transplants for open ground — up to 1 g/cm3.

For the normal life activity of plants, it is necessary that the air content in the substrate be no less than 10-12%, and the total porosity be 60-70%. The thickness of the nutrient substrate when growing vegetables in greenhouses is 30— 35 cm, and for transplants for open ground — 5-10 cm. It houses 85% of the root system.

When growing transplants for open ground, it is important that the mechanical composition of the substrate be light: a medium between light loam and sandy loam. The ratio of physical clay to sand should be 1:4.

Proper soils with the addition of organic and mineral fertilizers are widely used for growing vegetables in plastic greenhouses and transplants for open ground. In autumn, for cucumbers, 200 t/ha of manure (after 2—3 months of biothermal disinfection) is applied, and for tomatoes — 100-150 t/ha of humus.

Scarce humus can be successfully replaced with peat, straw, or sawdust at a rate of 25-30% of the volume of the tillage layer. To compensate for nitrogen consumption resulting from the activation of microbiological activity, an additional 10 kg of nitrogen per 1 ton of straw and 3—5 kg of nitrogen per 1 ton of sawdust is applied. Organic fertilizers for transplants are applied in a 5-10 cm layer, as the bulk of the roots are located there, and for vegetable crops — in a 30-35 cm layer.

To obtain high-quality transplants and high yields in a mini-orangery, it is important to prepare the soil correctly. Its mechanical composition should be close to light-loamy. For this, coarse-grained sand and organic looseners are added to ordinary soil. Their volume should be 30% of the nutrient layer with a thickness of 10 cm.

• Humus per 1 m² — 27 kg
• Peat per 1 m² — 9 kg
• Air-dry chopped straw per 1 m² — 1.2 kg

If natural soil is used in a greenhouse, its soil fertility can be improved using green manure. In experiments conducted at the beginning of August, immediately after harvesting, a vetch-oat mixture or white mustard was sown, and on November 1, the greenery was incorporated into the soil. In the following season, this resulted in an increase in yield of cucumbers and tomatoes by 1–2 kg per 1 m² compared to plots where ordinary humus was applied instead of green manure.

For raising seedlings, a mixture of two parts humus, one part soil, and one part sand is optimal. In plastic greenhouses, bulk soils are prepared from a mixture of peat (from 30 to 80%), manure or humus (from 10 to 30%), and soil (from 20 to 60%). Soil mixtures for hotbeds intended for transplants are selected depending on the planting dates.

To produce nutrient pots, the mixture composition is selected based on peat availability. In peat-rich regions, the mixture is made of three parts peat and one part humus. If peat is unavailable, pots are molded from humus and soil in a 5:1 ratio for sandy loam soil or 8:1 for loamy soil.

Selection and preparation of specialized substrates

In glass greenhouses, substrates are subject to higher requirements. Instead of traditional sod soil or lowland peat, it is more effective here to use upland or transitional peat, straw, sawdust, or bark. The main advantage of these materials is the complete absence of silt particles. Thanks to this, no crust forms on the surface, which would block air access to the root system.

However, such substrates also have a drawback — they are initially low in nutrients, and bark may contain harmful components. To improve quality, peat is limed, bark is composted, and mineral fertilizers are necessarily added to the substrate itself. In experiments, the yield of cucumber and tomato when grown on upland peat proved to be 16–25% higher than on a classic mixture of equal parts soil, lowland peat, and manure. Peat with a decomposition degree of no more than 10–20% and an ash content of 3–5% is suitable for this work.

1. Moisten the peat to 70% of the minimum water capacity.
2. Add chalk or lime flour to neutralize acidity (1 kg of deoxidizer per 1 m³ of peat raises the pH by 0.5–1 unit).
3. Compact the upland peat by 1.3–1.5 times immediately before planting the transplants.
4. Mix the prepared peat with manure in a ratio of 8–9 parts peat to 1–2 parts manure.

The fertility of the peat substrate is maintained by irrigation with a nutrient solution or by combining basic fertilizer application with periodic top dressing. For 1 m³ of upland peat, liquid micronutrient fertilizers are added: 2 g of ferrous sulfate, 1.5 g of magnesium sulfate, 1 g of zinc sulfate, 0.5 g of boric acid. Also, 0.4 g of copper sulfate and manganese sulfate are added, and 0.5 g each of ammonium molybdate, cobalt sulfate, and potassium iodide are added.

If there is no technical heating in the greenhouse, excellent results are provided by growing vegetables on a straw substrate. In the experiments, non-baled straw was used at a rate of 50 to 200 t/ha. The growing technology on loose straw is simpler than on bales, and the harvest is higher than on ordinary soil with artificial heating.

The high productivity of plants on straw is due to favorable microclimatic factors. The temperature of the substrate here rises to 25–27 °C, whereas in ordinary soil, it is only 20–21 °C. In addition, when straw decomposes, the air is enriched with carbon dioxide, and the released humic acids stimulate the development of the root system.