How to Grow in a Greenhouse?
Greenhouses are often associated with harvesting fresh home-grown tomatoes, peppers or cucumbers. However, successful cultivation of a wide range of vegetables, fruit and herbs in a greenhouse has its time-tested principles, which experienced growers follow so that they can enjoy a rich harvest once or even twice a year. Read about the advantages and pitfalls of greenhouse growing.
Advantages of growing in a greenhouse
What is the main advantage of greenhouses compared with growing on uncovered beds in the garden or in a field? The answer is: optimal growing conditions, to which some popular plant species are very sensitive. Unlike purely outdoor growing, a greenhouse makes it possible to maintain a constant temperature and humidity. Greenhouses also protect plants from adverse weather in the form of strong winds or heavy rain. (Below the article you will find a link to a separate article devoted to various stress factors that harm plants.) Greenhouses therefore allow plants to grow faster and crops to ripen more quickly. Growers make the greatest use of this especially when growing seasonal vegetables. Some vegetable varieties cannot really be grown without a greenhouse. If you have a greenhouse in your garden, you have much greater scope in terms of which varieties to grow.
Our TIP: A Dutch high-tech innovation also helps growers achieve optimal conditions in greenhouses: the intelligent TechGrow S-2 CO2 sensor. We also warmly recommend other unique devices from this manufacturer! For example, modern timers for your irrigation systems.
Another advantage of growing in a greenhouse is, of course, energy savings, because as far as plant lighting is concerned, you do not need an artificial light source and you use the sun, which shines on plants for free and whose light is intensified by clean glass (see below).
Another advantage of greenhouse growing lies in the head start. What do we mean by that? As mentioned at the beginning, harvesting can take place even twice a year. This is because while in open outdoor beds we usually plant tomatoes or peppers only during May, when the weather is sufficiently warm, a greenhouse gives growers up to a two-month head start, so more hardy vegetable species are commonly planted as early as March.
Ventilate, ventilate, ventilate
Ventilation, ventilation, and plants will be protected from mould... Not only for this reason should regular air exchange be a matter of course when growing in a greenhouse. If it is not, an environment is automatically created in which plants, put simply, struggle to breathe. Excessive humidity forms inside the growing space, which increases the risk of plants being affected by mould or other fungal diseases. A common mistake is also to rely on just one ventilation opening. You should always open at least two windows to ensure sufficient air circulation inside the greenhouse. On warmer days, opening the doors is an option, but bear in mind that the larger the ventilation opening, the easier it is for pests to get inside. After all, a greenhouse is not a grow box, so you should definitely think about effective prevention. Also read the article: How to deal with pests? A great helper is especially the popular Canna CURE spray. On the other hand, by opening ventilation openings including the doors, we give useful flying insects, namely pollinators, the opportunity to look into the greenhouse, and they thus fulfil their role given by nature inside the greenhouse and help us achieve a wonderful harvest. To summarise:
- Ventilate thoroughly in combination with effective prevention.
- Opening at least two ventilation openings on opposite sides of the greenhouse ensures that air circulates naturally in the growing space.
- In spring, ventilate only during the day, when outdoor temperatures reach their maximum, and do not forget to close the ventilation openings at night so that night-time temperature fluctuations do not endanger the development of your plants; greenhouse heating can also help protect them from these fluctuations (see below).
Make the most of the space
Efficient use of space in a greenhouse makes it possible to multiply the amount of tasty produce or fragrant herbs you will be able to harvest. For this purpose, greenhouse shelving or window ledges are purchased for greenhouses. Handy DIY enthusiasts can also make them themselves. The material is not as important as stability, because damp soil has considerable weight. They are perfect, among other things, for pre-growing seedlings in pots. Some shelves are foldable, others are not. The advantage of foldable shelves is that they do not later get in the way of larger plants. Under fixed shelves you can grow lower vegetables and set up another level on shelves where you place window boxes with basil and other heat-loving plant species. Ideally, the shelves should have various openings through which the flowing air can also reach the lower level.
Tips for pots for a healthy root system and higher yields
Fabric pots are made with sustainability in mind. After harvest, you can simply wash them and use them again for the next growing cycle. Unlike plastic pots, there is no risk of the growing container degrading, and you ensure perfect drainage of the substrate as well as its aeration, meaning an above-standard supply of oxygen to the roots. Read the article: When should fabric pots be preferred over plastic ones? From plastic pots, we recommend aerated HERCULES pots for excellent root development. The picture clearly shows how well plant roots thrive in them.
Some growers prefer beds in the greenhouse, supplemented by hanging pots for maximum use of the growing space. If you decide to give preference to cultivating plants in beds inside the greenhouse, do not forget to get quality soil substrate and replace it regularly, or revitalise it. Substrate revitalisation is the subject of the article: How and why should substrate be revitalisedsubstrate? Regular revitalisation and replacement of spent substrate in greenhouse beds is part of important prevention against mould and plant pest infestations. If your priority is to harvest tasty crops in organic quality, we recommend, for example, BioNova Bio Soilmix.
Advantages and pitfalls of the greenhouse effect
This process, which we already know from school, allows plants to grow faster and produce fruit that also ripens more quickly. Fruiting vegetables are therefore usually the number one topic in greenhouses. Short-wave radiation enters the greenhouse through the glass, creating heat that is retained very well inside. Growers and gardeners use this every year as early as spring for pre-growing seedlings. The greenhouse effect is beneficial in most situations, but it is said that too much of a good thing can be harmful. This also applies to too much sun, whose rays are intensified by the glass. During the hot summer months, care must be taken to ensure that extreme temperatures do not develop inside the greenhouse. In our e-shop, you can choose from a wide range of devices for measuring temperature and humidity.
Heating the greenhouse
Protect your plants in the greenhouse from sudden drops in temperature or low night-time temperatures and provide them with a stable environment using special heating.
We recommend the reliable tubular heating elements LightHouse ECOHEAT, made directly for greenhouse growing purposes in four variants. Simply choose the required output to (45 W, 80 W, 135 W or 240 W) according to the size of the greenhouse.
You can easily attach the practical heating elements to the greenhouse wall, but you can also place them directly next to the plants without any problem, as they are resistant to sprayers and water splashes. You can see both options in the picture.
Greenhouse heating will certainly also come in handy for safely overwintering portable plants.
Heating the greenhouse is certainly a suitable support for plant development during the colder months, but do not forget that if you want to grow plants in a greenhouse in winter, in addition to heating the greenhouse you must also obtain sufficiently powerful artificial lighting. And heating a large space with artificial lighting is already a fairly costly matter. Year-round growing of any plant species under artificial lighting is also made possible by grow tents of various sizes, thanks to which you can harvest in the comfort of your home from spring to winter.
Clean glass and birds
If you keep the glass permanently perfectly clean, you maximise the effectiveness of the sun's rays that pass through the glass and fall on photosynthesising plants. In other words, it would certainly be a shame if your efforts were slowed down by a layer of dust or other dirt from the surrounding environment. For example, lettuces typically, as a result of a layer of dust on the greenhouse, do not absorb light rays with sufficient intensity and tend to accumulate nitrates in themselves.
However, too much of anything is harmful, and therefore, when it comes to the pitfalls associated with growing plants in a greenhouse, caution is especially necessary in summer. We have already mentioned the greenhouse effect. The accumulating heat inside the greenhouse could damage plants, so it is worth using proven methods, such as coating the greenhouse surface with a protective lime wash, which can be removed quite easily after the season with water and vinegar. These coatings are usually inexpensive, and you do not need to worry about damaging the glass in any way.
As for the clear glass, it is also important not to underestimate speed and not to overestimate the perception of birds flying over the property on which your greenhouse stands. A little translucent paint or UV stickers on the glass will protect the lives of birds and at the same time prevent damage.
If you have any questions about greenhouse growing, we will be happy to advise you at the well-known e-mail address info@higarden.eu. This also applies, of course, to choosing suitable products that will make your work in the greenhouse considerably easier and increase yields. We are here for you!
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