How to prepare greenhouse for the fall and for the spring

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ClimaPod Greeenhouse Tips: how to prepare greenhouse for the fall and spring season

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 that can be combined with the humid microclimate inside the greenhouse can encourage pests and pathogens to thrive. They can safely overwinter and destroy the next year’s crop. Unless you’re growing in a greenhouse year-round, the greenhouse doesn’t just need to be cleaned. You should treat this with special products after the end of the season in the fall. We also recommend to prepare your greenhouse in the spring before planting.

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 carried out in the fall after harvest. You should remove all plant residues. If the plants suffered from any diseases or attracted the attention of harmful insects, you should pay special attention. It is highly likely that the larvae of these pests, pathogenic plants or spores remained to winter. They can be in the upper layers of the soil, on walls, ceilings, shelves, inventory, supports and garters. They will be active in the spring as soon as favorable conditions come. 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. We strongly recommend that you take care of increasing soil fertility. This must be done in addition to all the necessary work that you have to do. We all understand that it is unlikely that your soil will remain fallow for several years, so this makes sense. Year after year it will just clean up all the nutrients of the soil.

We do not recommend leaving any greens, such as vegetable leaves or flower stalks grown in covered greenhouse soil. You should not hope that it will become fertilizer, especially if the plants were sick. 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.

It is necessary to collect and burn the remains of plants, ropes, pegs and other garbage.
It is necessary to collect and burn the remains of plants, ropes, pegs and other garbage.

The replacing of the upper fertile layer of the soil will also help to get rid of harmful microorganisms. And it will definitely help to increase the future harvest. If you do not have the opportunity to do this, then you can remove a layer of soil about 10 – 15 cm thick. Then you should warm it up on a fire, then 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.

Greenhouse cleaning

First of all, you need to carefully inspect the greenhouse after winter. At the same time, you will immediately find out if something is rotten or broken somewhere. Therefore you have to fix and replace all the broken or defective items. You should fix, replace or paint shelving, shelves, partitions. You should also thoroughly wash all glass surfaces on both sides with a quality glass washer. After this procedure, rinse everything with a stream of water so that the maximum possible amount of sunlight gets inside the greenhouse. Thoroughly inspect and wash film or polycarbonate covers with soapy water. You may need to replace the film 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.

Greenhouse disinfection

If any diseases have affected your plants during the growing season, then you should treat and fight their spreaders in the autumn after harvest. In the spring, you should use a milder preventive treatment. Your vegetables could get late blight, black leg, white rot. Last season you may have found a root nematode. In these cases, the best way to help your plants get healthy again is to use bleach. Even if the soil and plants in the greenhouse were well tilled in the fall, it’s still a good idea to spray all your plants in the spring with the same liquid solution. To prepare the right liquid first of all you have to add 400 g of lime into the 10 L of water. Then you have to give it at least 4 hours to brew. After all the manipulations, you will have a settled upper part of the aqueous liquid. You can use the resulting liquid 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 this if you find keeled, root rot, black leg or verticillium wilt on vegetable plants. You will have to treat one square meter of earth with two liters of carbation to get rid of all these diseases. Dig up the ground after processing.

greenhouse disinfection
Prepare greenhouse for the fall: greenhouse disinfection

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, it is better for you to process at a temperature of greenhouses not higher than 10-12 degrees Celsius. Otherwise, it will simply evaporate, and we need the processing to remain inside for a while. Pour 40% liquid formalin solution over the entire area of the greenhouse. Then raise the temperature inside the tightly closed greenhouse to plus 25 degrees Celsius. The person who will be handling formalin should only work in a gas mask and follow all safety precautions. We highly recommend you to keep the greenhouse closed for at least 24 hours after treatment. Only then should it be well ventilated. You can apply formalin at least a month before planting seedlings in the greenhouse. It is possible that the formalin liquid can somehow be retained or even concentrated in the concrete. Therefore, if possible, it is much better if you do 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 fall it is better to use large dose of strong concentration of copper sulfate. 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.

The chemical industry has created special preparations to combat certain pathogenic bacteria. All of these drugs have worked well. If you decide to use such drugs, carefully read the instructions before use. Keep in mind that not every drug you can use 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 follows: for one cubic meter of cultivated area, you need to take about 50-80 g of sulfur. If you have spider mites, take a double dose of sulfur. You should start processing after you have cleared all the cracks in the greenhouse structure and ensured its tightness. The greenhouse must be closed for at least three days for your safety. 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.

disinfection of the greenhouse soil
disinfection of the greenhouse soil

It is better to say that you should disinfect greenhouse in spring. But it is better for you to focus only on those diseases and those pests that you have definitely 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 % of copper sulfate or 50 g of bleach per one liter of water for cleaning all the tools.

You can treat wooden tools with blue vitriol, and then just whitewash with lime. Simply scald metal tools and fixtures 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 disinfection of the greenhouse, you will need to spill the earth with boiling water. Then just dig up the soil with the usual spring dose of fertilizer.

Note: The recommendations and tips contained in this article are provided for informational purposes only. We do not recommend that you perform work related to the use of chemicals without proper training. If you are not sure that you can do everything right, it is better to seek the help of professionals.

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