The greenhouse gives an opportunity to grow heat-loving plants or simply get a crop of vegetables much earlier than the weather-climate conditions allow. But the heat which can be combined with humidity microclimate inside the greenhouse can contribute to the cultivation of pests and pathogens that can overwinter and destroyed the crop of the next year. That is why the greenhouse should not be cleaned up in simply way but also treated with special means after the end of the season in the autumn and in the spring before planting starts.
Why to treat the greenhouse after winter
The preparation of the greenhouse for the future season starts a long time before planting of the vegetables early in the spring. At the time when the seedlings are just about to rise on the windowsills and the snow is still prevailing in the vegetable garden. The main cleaning of the garden should be done in the autumn after harvesting when all plant remains are removed. If the plants were suffered from any kind of diseases or had attention of harmful insects it means that it is highly possible that the larvae of these pests, pathogenic plants or spores remained overwintering in the upper layers of the soil, on the walls, ceilings, shelves, inventory, supports and garter materials. If the favorable conditions will be created they will show activity in spring time. All of it means that the next year’s harvest will be under the danger.
That is the reason why in the greenhouse has to take place not only such kind of works as repairing and cleaning up but also number of decontamination works after the winter season will be over. In addition to all necessary works that have to be done it is highly recommended to take care about increasing the fertility of the soil. It makes sense because we all know that it is unlikely soil to be left for several years under steam. Year after year it will just clean up all the nutrients of the soil.
Any greenery such as the top of the vegetables or the stems of flowers that was grown in the closed greenhouse ground should not be left on the soil hoping that it will become the fertilizer especially if the plants suffered diseases. Such plant residues will do more harm than help. The best way is to remove or even better to destroy all the remnants. It is interesting to know that fungal spores, harmful bacteria, larvae and pest eggs have a very small size. They can hide on pegs, garter ropes, in the slightest slits on the joints of walls and even on the ceiling. It is very hard to eliminate all of this by adhering to the rules of the crop rotation or sowing crops before planting the main crops. This activity should be combined with the chemical treatment of the entire greenhouse when spring time comes from those infections and pests that were seen on plants during the vegetative period.
The replacing of the upper fertile layer of the soil will also help to get rid of harmful microorganisms and will definitely help to increase the future harvest. If there is no way to do this you can still collect the layer of the soil approximately 10 – 15 cm thick then it should be warmed up over the fire and then to mix it with complex fertilizers. You have to remember that it is possible to treat the land with the chemicals only in the autumn but not in the spring time before planting. In spring time you can use only solution of copper sulfate or Bordeaux liquid as the treatment for soil.
First of all the greenhouse should be inspected after winter. During the process of inspection it will certainly be found that somewhere something has rotted or broken. Therefore you have to fix and replace all the broken or defective items. The racks, shelves, partitions should be corrected, replaced or painted. All glass surfaces have to be thoroughly washed from both sides with good quality glass-washer liquid and after this procedure it should be washed with a strong stream of water to admit the maximum possible amount of sunlight inside the greenhouse. The film or polycarbonate coatings which were not removed for the winter have to be thoroughly inspected and washed with soapy water. The film is quite possible will necessary need to be replaced in some places.
Most likely the soil in the greenhouse will be still covered with the snow. Some owners dig through the soil after autumn harvesting and then cover it with pure snow which remains there all winter season long. In the early spring when cleaning in progress it is necessary to accelerate the process of snow melting. For this process snow should be covered with something black. It may be just land, humus, compost or ash. It is enough to scatter a thin layer so that the white snow does not reflect sunlight. If you will use the heaters than the process will definitely go faster.
It’s time to move on to the step of disinfection when the ground warms up enough to be dig through. It is better to process with the safe types of substances that will protect future plants from diseases and pests and help the owner of the greenhouse to grow healthy and organic vegetables.
If the plants were suffered from some kind of diseases during vegetation period than the main struggle with diseases and their distributors will take place during autumn period after harvesting. The softer preventive treatment should be used during the spring time. So if the vegetables were sick with late blight, black leg, white rot or if the root nematode was found during the last season then the best way to help your plants to be healthy again is to use the chlorine lime liquid. Even if the greenhouse soil and plants were treated well in the autumn it is still worthwhile sprinkling all your plants with the same liquid solution in the spring time. To prepare the right liquid first of all you have to add 400 grams of lime into the 10 liters of water and then you have to give it at least 4 hours to brew. After all the manipulations the stood top of water liquid that you will get should be used for transparent walls and roofs. The sediment water liquid is better to use for wooden structures.
At least one month before the moment of appearance of the plants in the greenhouse it is better to treat the ground with carbothion. You should do it in case if the keel, root rot, black leg or verticillium wilt was recognized on the plant of vegetables. To rid of from all of these diseases you have to treat one square meter of the ground with two liters of carbathion. After the treatment the ground should be dug.
In case you need to get rid from such kind of diseases as spider mite, mold, whitefly larvae it is better to use formalin liquid solution. In this case the process of treatment has to be done when the temperature of the greenhouses is not higher than 10 – 12 degrees Celsius otherwise it will simply evaporate but we need the treatment to stay inside for a while. The forty-percent liquid solution of formalin should be used for watering the entire area of the greenhouse and then the temperature inside the tightly closed greenhouse should be raised up to plus 25 degrees Celsius. The person who will work with formalin treatment should only work in the gas mask. It is highly advisable to keep the greenhouse area closed for at least 24 hours after the treatment will be done and only after that time it should be well ventilated for future needs. The formalin liquid can also be used only one month before planting the seedlings in the greenhouse. It is possible that formalin liquid is somehow preserved or even concentrated in the concrete so if it is possible it is much better if you will not water the concrete elements with formalin liquid.
The prevention process against diseases such as all kinds of bacteriosis, powdery mildew, various rot and blotchiness, late blight, rust, curl, scab is getting rid out with the help of copper sulfate. If it is autumn it is better to use large dose of strong concentration of copper sulfate or if it is spring time it is enough to take ten percent copper sulfate liquid solution to spray the entire inner part of the greenhouse.
Of course there are special drugs for fighting against certain bacteria that carry and provoke diseases that were created by the chemical industry. All of these drugs have proved themselves well but the main thing is to study the instructions carefully before use. You have to note that not all preparations can be used in the spring.
Sulfur is the most common means for spring disinfection. The lumps of sulfur watered with kerosene lay out or put a smoldering ember nearby along the entire length of the greenhouse building on the metal sheets and then set them on fire. The recipe is as following you have to take about 50 – 80 gram of sulfur per one cubic meter of the area that have to be treated. In case if there is present spider mite you have to double the dose of sulfur. The treatment should be started only after all the cracks and slits in the greenhouse building have been cleared and the tightness of its have been ensured. The greenhouse building has to be kept close for at least three days. Since the smoke is very dangerous not only for pests of course the person who does the treatment has to use protection methods such as respirator, goggles, gloves or even preferably the protective suit and the gas mask. There are special smoke sulfur checkers which are more convenient to use. The sulfur or even more precisely its smoke destroys the metal so that is another rule you have to follow. The greenhouse buildings with metal frames are better not to process at all.
It is better to say that it is necessary to do the disinfection of the greenhouse in the spring time but it is preferable to be oriented only against those diseases and those pests that have been accurately observed before. You have to know that the excess effect of the poisons will not be beneficial future harvests.
All those things and tools that will just stand next to the plants can bring them infection in a future too. So it is worth to remember and carefully clean all the tools, utensils and other supporting equipment. You can use 50 percent of copper sulfate or 50 gram of bleach per one liter of water for cleaning all the tools.
The wooden tools can be treated with copper sulfate and then just use lime whitewash. The metal tools and equipment is just simply scalded with boiling water.
The best way to avoid all the diseases is complete replacement of the greenhouse soil but most of all this is rarely possible. Usually after all the greenhouse disinfecting actions the ground should be spilled with boiling water and then just dig over with the spring dose of fertilizers adding.Tags: greenhouse, tips