{"id":16903,"date":"2026-02-09T16:11:23","date_gmt":"2026-02-09T13:11:23","guid":{"rendered":"https:\/\/novateplica.com.ua\/?p=16903"},"modified":"2026-02-09T16:11:23","modified_gmt":"2026-02-09T13:11:23","slug":"kak-pravilno-obrabatyvat-tepliczu-v-mezhsezone-polnoe-ekspertnoe-rukovodstvo","status":"publish","type":"post","link":"https:\/\/novateplica.com.ua\/en\/kak-pravilno-obrabatyvat-tepliczu-v-mezhsezone-polnoe-ekspertnoe-rukovodstvo\/","title":{"rendered":"How to properly treat a greenhouse in the off-season: A complete expert guide"},"content":{"rendered":"
You have invested money, time and soul in your crop, but at the end of the season the greenhouse looks like a battlefield? Yellowed polycarbonate, suspicious plaque on the frame and the fear that phytophthora or spider mites \u201coverwinter\u201d with you? You are not alone. Every year thousands of gardeners in Ukraine lose up to 40% of next year's crop precisely because of improper preservation of the structure.In this article we will understand how to turn your greenhouse into a sterile and safe zone for new records, based on technical regulations, chemical calculations and experience of Nova Teplitsya experts.<\/header>\n
\n

Why isn't just \u201cwashing with water\u201d enough?<\/h2>\n

\"greenhouse<\/p>\n

The off-season (October-November or February-March) is a critical period. Pathogenic microorganisms (fungal spores, bacteria) and pest larvae are highly resistant to low temperatures. Without chemical and mechanical disinfection, the infectious background in the closed ground accumulates 5-7 times faster than in open beds.<\/p>\n<\/section>\n

\n

Step 1: Deep mechanical cleaning and technical audit<\/h2>\n

Before starting disinfection, it is necessary to prepare the \u201cbase\u201d. Chemical preparations will not work effectively if a layer of dirt or organic matter remains on the surfaces - they will become a physical barrier to the antiseptic.<\/p>\n

1. Complete cleanup of organic debris<\/h3>\n
    \n
  • Root removal:<\/strong>\u00a0Nematodes and fusarium pathogens overwinter in the roots of tomatoes and cucumbers. Pull out the plants completely.<\/li>\n
  • Twine and Garter Ties:<\/strong>\u00a0Cloth ropes are the perfect incubator for spores. Dispose of them.<\/li>\n
  • Compost Verdict:<\/strong>\u00a0Greenhouse residues are contaminated in 90% cases. Incineration is the best way out.<\/li>\n<\/ul>\n

    2. cleaning the coating: fighting for every lux of light<\/h3>\n

    Dirty polycarbonate traps up to 30% of solar energy. Use soft microfiber mops. Do not use metal scrubbers to avoid damaging the UV layer.<\/p>\n

    3. inspection of the frame and fittings<\/h3>\n

    Check galvanized profile for \u201cwhite rust\u201d and touch up chipping on painted frames. Check the seals to prevent moisture from getting inside the polycarbonate honeycomb.<\/p>\n<\/section>\n

    \n

    Step 2: Disinfectant Selection and Application - A Scientific Approach<\/h2>\n

    In Ukraine, the use of agrochemicals is strictly regulated. For closed soil, it is not allowed to use preparations of the first class of hazard. Let us analyze the three most effective strategies, their physics and economics.<\/p>\n

    1. Copper Sulfate (Copper Sulfate, CuSO4) - Fungicide Armor<\/h3>\n

    Copper is a powerful inhibitor of fungal enzymes. Upon contact with the spore, copper ions penetrate inside and block its respiration, which leads to the death of the pathogen even before its activity begins in spring.<\/p>\n

      \n
    • Who it's suitable for:<\/strong>\u00a0Universal for polycarbonate, glass and film. Safe for galvanized and painted frames.<\/li>\n
    • Cooking technology (algorithm for the beginner):<\/strong>\n
        \n
      1. Use only plastic containers. Copper reacts with iron and the solution loses its properties.<\/li>\n
      2. Dissolve a weight of powder in 1 liter of hot water (about 50 degrees Celsius) until the crystals disappear.<\/li>\n
      3. Top up with cold water to a total volume of 10 liters.<\/li>\n
      4. Strain through gauze before pouring into sprayer to avoid clogging nozzles.<\/li>\n<\/ol>\n<\/li>\n
      5. Dosage and calculation of consumption:<\/strong>\n
          \n
        • Prevention:<\/strong>\u00a0100 g per 10 liters of water (1% solution). Consumption: 2 liters of ready solution per 10 square meters of surface.<\/li>\n
        • Eradication treatment:<\/strong>\u00a0300 g per 10 liters of water (3% solution). It is used if there was an epidemic of Phytophthora or powdery mildew in summer.<\/li>\n<\/ul>\n<\/li>\n
        • Fact:<\/strong>\u00a0Copper does not evaporate, it creates a protective film that works until the first serious washing of the greenhouse.<\/li>\n<\/ul>\n

          2. Sulfur Bomb (Sulfur Dioxide, SO2) - Gas Disinfection<\/h3>\n

          When sulfur burns, it releases gas that fills the entire volume of the greenhouse, penetrating into the microcracks of the frame and the topsoil. When combined with moisture (condensate), the gas forms sulfuric acid.<\/p>\n

            \n
          • Critical Framing Warning:<\/strong>\u00a0It is strictly forbidden to use in greenhouses with a frame made of unpainted black metal or aluminum.
            \nTechnical risk:<\/em>\u00a0Acid causes instant corrosion, which can destroy a thin-walled profile in 1-2 seasons.<\/li>\n
          • How to secure galvanizing:<\/strong>\u00a0Lubricate all metal parts (bolts, hinges, handles) with a layer of solidol or lithol. This will create an airtight grease film through which the gas will not pass to the metal.<\/li>\n
          • Calculating the number of checkers:<\/strong>\n
              \n
            • A standard saber (300 g) is rated for 5 cubic meters of volume for insect control and 10 cubic meters for fungus control.<\/li>\n
            • Example calculation:<\/strong>\u00a0A 3 by 6 meter greenhouse with a height of 2 meters has a volume of 36 cubic meters. For effective disinfection you will need 4 full a checkers (36 divided by 10 and rounded up).<\/li>\n<\/ul>\n<\/li>\n
            • Safety Measures:<\/strong>\u00a0After burning, leave the greenhouse immediately and close the doors tightly. The exposure period is from 24 to 72 hours. After that, mandatory ventilation for 2-3 days until the specific odor disappears completely.<\/li>\n<\/ul>\n

              3. peracetic acid (NSAID) - Professional eco-methods<\/h3>\n

              It is a mixture of hydrogen peroxide and acetic acid. The most powerful oxidizing agent that destroys not only fungi, but also bacterial infections and plant viruses (e.g. tobacco mosaic virus).<\/p>\n

                \n
              • Prerequisite:<\/strong>\u00a0It is a completely biodegradable product. It breaks down into water, oxygen and ordinary table vinegar. It leaves no residue on polycarbonate, on the contrary, it removes lime scale from hard water.<\/li>\n
              • A recipe for a powerful working solution:<\/strong>\n
                  \n
                • For 10 liters of water, take 2 liters of 3% pharmacy hydrogen peroxide and 1 cup (200 ml) of 9% table vinegar.<\/li>\n
                • To enhance the effect, you can add 2 tablespoons of liquid soap as a sticking agent.<\/li>\n<\/ul>\n<\/li>\n
                • Temperature conditions:<\/strong>\u00a0NUC is most effective at air temperatures above +15 degrees Celsius. If the greenhouse is colder, the exposure time should be doubled.<\/li>\n<\/ul>\n

                  Comparative table of disinfection methods<\/h3>\n\n\n\n\n\n\n\n\n
                  Criterion<\/th>\nCopper sulfate<\/th>\nSulfur dart<\/th>\nPeracetic acid<\/th>\n<\/tr>\n<\/thead>\n
                  Spectrum of action<\/strong><\/td>\nFungi, lichens<\/td>\nFungi, insects, mites, rodents<\/td>\nFungus, bacteria, viruses<\/td>\n<\/tr>\n
                  Complexity of work<\/strong><\/td>\nMedium (spraying)<\/td>\nHigh (sealing)<\/td>\nLight (wipe\/spray)<\/td>\n<\/tr>\n
                  Effect on metal<\/strong><\/td>\nNeutral<\/td>\nAggressive (corrosion)<\/td>\nNeutral<\/td>\n<\/tr>\n
                  Environmental friendliness<\/strong><\/td>\nAccumulates in the soil<\/td>\nMedium (toxic gas)<\/td>\nMaximum<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/section>\n
                  \n

                  Step 3: Soil Regeneration - Restore the \u201cheart\u201d of the greenhouse<\/h2>\n

                  The soil in the greenhouse works under extreme stress. Lack of natural crop rotation and constant microclimate lead to two problems: \u201cfatigue\u201d of the soil and accumulation of pathogenic background. If on the open ground the soil is restored by precipitation and freezing, in the greenhouse all the responsibility falls on the gardener.<\/p>\n

                  1. Mechanical renewal: when you need to \u201creplant\u201d the soil<\/h3>\n

                  Up to 90% of pest larvae (spider mites, whiteflies) and fungal spores are concentrated in the upper 5-10 centimeters of soil. In addition, ballast salts from mineral fertilizers accumulate here, which make the soil toxic for roots.<\/p>\n

                    \n
                  • The Golden Rule:<\/strong>\u00a0Replace the top layer (10 cm) every 3 years.
                    \nA calculation for a beginner:<\/em>\u00a0For a standard 3 by 6 meter greenhouse, the bed area is about 18 square meters. A 10 cm layer is 1.8 cubic meters of soil. On average, this is about 45-50 garden wheelbarrows of fresh soil.<\/li>\n
                  • What to replace it with:<\/strong>\u00a0The ideal greenhouse substrate is a mixture of sod earth, humus (2-year-old) and river sand in a ratio of 2:2:1.<\/li>\n
                  • Important:<\/strong>\u00a0Never take soil from the beds where related crops grew (potatoes after tomatoes), so as not to transfer diseases.<\/li>\n<\/ul>\n

                    2. biological disinfection: an army of microscopic defenders<\/h3>\n

                    If you do not plan to replace the soil this year, it is necessary to carry out its \u201crecovery\u201d with the help of biopreparations. Unlike aggressive chemistry, the biomethod does not kill earthworms and useful microflora.<\/p>\n

                      \n
                    • Trichoderma (Trichoderma):<\/strong>\u00a0Predator fungus. It finds spores of pathogens, braids them with its filaments (mycelium) and literally digests them.
                      \nInstructions:<\/em>\u00a0Apply preparations (Trichophyte, Trichocin) when digging.
                      \nImportant fact:<\/em>\u00a0Trichoderma is active only when soil moisture is above 60% and air temperature is more than +10...+12 degrees Celsius. In dry and cold soil it \u201cfalls asleep\u201d.<\/li>\n
                    • Hay bacillus (Bacillus subtilis):<\/strong>\u00a0A useful bacterium (the basis of Phytosporin-M). It secretes more than 70 types of natural antibiotics that inhibit the development of diseases.
                      \nAdvice:<\/em>\u00a0After watering with biopreparations, mulch the beds with a layer of straw - this creates ideal conditions for bacterial growth.<\/li>\n<\/ul>\n

                      3. Phytosanitary sowing: Siderates against infections<\/h3>\n

                      Siderates are plants that are doctors. Their sowing immediately after treatment of the greenhouse with vitriol or gas allows you to restore the fertility of the land in a matter of weeks.<\/p>\n

                        \n
                      • White mustard:<\/strong>\u00a0A leader for greenhouses. Its roots secrete special substances (glucosinolates), which are not tolerated by wireworm larvae and parsch pathogens.
                        \nSeeding rate:<\/em>\u00a0400-500 g of seeds per greenhouse 3x6 m.<\/li>\n
                      • Phacelia:<\/strong>\u00a0A versatile choice. It changes the soil acidity (Ph) towards neutral and builds up green mass very quickly.<\/li>\n
                      • Vico-oat mixture:<\/strong>\u00a0The best option for nitrogen recovery.
                        \nComparison:<\/em>\u00a0Incorporation of green mass of oats with vetch in the amount of nitrogen is equivalent to the introduction of 50 kg of manure per 10 m2, but you do not bring in the greenhouse weed seeds and larvae of the May beetle.<\/li>\n<\/ul>\n

                        4. Watch out for organics!<\/h3>\n

                        Many beginners believe that the best way to prepare the soil is to cover it with fresh manure from the fall.\u00a0This is a dangerous misconception:<\/strong><\/p>\n

                          \n
                        1. Fresh manure in the closed ground causes a powerful release of ammonia, which can \u201cburn\u201d polycarbonate and frame (cause darkening).<\/li>\n
                        2. Manure is the main source of beetle and codling beetle larvae entering the greenhouse.<\/li>\n
                        3. Excess nitrogen in the fall will cause plants to be \u201cfat\u201d in the spring (lots of leaves - no fruit).<\/li>\n<\/ol>\n<\/section>\n
                          \n
                          \n

                          Technical requirements for polycarbonate: Secrets of durability<\/h2>\n

                          \"greenhouse<\/p>\n

                          Polycarbonate is a technological polymer, the quality of which in Ukraine is regulated by state standards (DSTU). It is important for a beginner to understand the difference between \u201ccheap plastic\u201d and quality coating.<\/p>\n

                            \n
                          • UV protection (Coextrusion):<\/strong>\u00a0This is a critical parameter. The protective layer must be coextruded (fused into the surface), not sprayed.
                            \nFact:<\/em>\u00a0Without UV protection polycarbonate is destroyed under the sun in 2 years: it becomes brittle like glass, and crumbles from light hail. A quality sheet should have a protective layer with a thickness of at least 40-50 microns.<\/li>\n
                          • Density and weight:<\/strong>\u00a0For greenhouses, the optimum thickness is 4 or 6 mm. But not only the thickness is important, but also the specific weight. A quality 4 mm sheet should weigh at least 0.7-0.8 kg per square meter.
                            \nComparison:<\/em>\u00a0\u201cLightweight\u201d polycarbonate weighing 0.5 kg\/m2 will crumple under the first snow.<\/li>\n
                          • Chemical Inhibitions:<\/strong>\u00a0The structure of polycarbonate is sensitive to alkalis.
                            \nRule:<\/em>\u00a0Never use ammonia-based window cleaners or aggressive detergents. Only a weak soap solution (pH below 10) is acceptable.<\/li>\n
                          • Cell sealing:<\/strong>\u00a0The ends of the sheets should be closed with perforated tape and end profile. If the honeycomb is left open, condensation and algae will grow inside and turn a transparent sheet into an opaque \u201cgreen shield\u201d, blocking up to 50% of light.<\/li>\n<\/ul>\n<\/section>\n
                            \n

                            Snow load calculation: How not to find your greenhouse \u201cfolded\u201d in spring<\/h2>\n

                            Ukraine is divided into several snow regions. In the northern and central regions, the load can reach 160 kg per square meter of horizontal surface.<\/p>\n

                              \n
                            • The physics of the process:<\/strong>\u00a0The snow on the greenhouse does not always slide off by itself. When temperatures change (thaw during the day, frost at night), an ice crust forms on the surface, to which new layers of snow stick. The weight of wet snow can be 3-4 times the weight of fresh snow.<\/li>\n
                            • Load Math:<\/strong>\u00a0A 3 by 6 meter greenhouse has a projection area of about 18 square meters. With a norm of 120 kg\/m2, the total load on the frame can be more than 2 tons.<\/li>\n
                            • How to strengthen the structure:<\/strong>\n
                                \n
                              1. Arc Pitch:<\/strong>\u00a0The optimal pitch for Ukrainian conditions is 0.65 m. If you have a pitch of 1 m, the risk of deformation increases 2 times.<\/li>\n
                              2. Winter Supports:<\/strong>\u00a0If you don't plan to shovel snow, install inside T-shaped wood or metal stanchions under each ridge (center longitudinal lintel).
                                \nImportant:<\/em>\u00a0Place a wide board under the base of the stanchion to keep it from sinking into the soft greenhouse soil under the weight of snow.<\/li>\n<\/ol>\n<\/li>\n<\/ul>\n<\/section>\n
                                \n

                                Nova Teplitzia Expert Opinion: Professional tricks<\/h2>\n

                                We asked Nova Teplice's lead engineer about the most common mistakes and non-obvious tips for the off-season.<\/p>\n

                                \u201cA lot of people think that closing a greenhouse \u2018tight\u2019 is a good thing. That's a mistake.\u201d<\/strong><\/p>\n

                                 <\/p>\n

                                Why you should open your greenhouse in the winter:<\/strong><\/p>\n

                                  \n
                                • Thermoregulation:<\/strong>\u00a0On sunny days in February, the temperature inside the greenhouse can rise to +15 degrees Celsius, while outside it is -10 degrees Celsius. This difference creates enormous stress in the polycarbonate and causes abundant condensation. Micro-ventilation equalizes the temperature.<\/li>\n
                                • Freezing pests out:<\/strong>\u00a0Many insects (e.g. whitefly larvae) die at temperatures below -15 degrees Celsius. If the greenhouse is closed, the soil may not freeze to the correct depth.<\/li>\n
                                • Snow inside the beds:<\/strong>\u00a0In January-February we recommend to specially cover the beds inside the greenhouse with a layer of 20-30 cm of snow. In spring, this will provide \u201cliving\u201d melt water, which perfectly flushes the soil of salts and awakens useful bacteria.<\/li>\n<\/ul>\n<\/blockquote>\n<\/section>\n<\/section>\n