What to grow and what not in a polytunnel? One might think that, thanks to optimal conditions created inside the greenhouse, any plant is suitable for under cover cultivation. Well, sometimes you would rather leave some crops outside, as long as they can cope without cover protection. There are also a few contraindications regarding space management in a polytunnel. In this Krosagro blog, we will talk about choices when growing under cover.
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What to grow and what not in a polytunnel?
In the last 10 years, the number of hobby and professional tunnels sold has increased sevenfold. This is probably due to the fact that many people now understand the benefits of cultivation under cover. Some gardeners use this facility as support for their activity, while others have based their entire production on it. The additional 60 days of growth offer a significant set of possibilities. Cultivation of tropical plants under cover, cultivation of slow-ripening varieties, creation of a seedlings and a year-round plantation are just a few possibilities.
Under cover
Polytunnel frames are hot-dip galvanized at production stage. This treatment protects them against corrosion, which would appear with permanent exposure to moisture. Elements thus protected do not deteriorate and remain functional for years. The foil on the structure maintains a favorable microclimate inside. Heat is stored under the plastic membrane, contributing to better air and soil conditions and for longer than in open field cultivation. Plants do not lose energy on protection against the cold, and focus on growth, flowering and fruiting.
Temperature in the greenhouse
During cold months, when outdoor temperatures increase gently, plants start to develop. The heat slowly intensifies under the cover and creates favorable conditions. In case of frost, plants are safe.
This is especially important for crops showing early signs of maturity. Sudden drops in temperature can lead to weakening of plants. If such conditions persist for a long time, it can even lead to their death. To avoid this, plants are covered with agro textile. In areas where winter lasts longer, a mini tunnel can be installed as an extra protection. It is a small construction, very similar to a full-size one. By combining small tunnel and a large greenhouse, growers have a chance to grow all year round, as well as protect more delicate varieties.
Space for crops
Krosagro polytunnels are modular steel structures that can be extended indefinitely. However, each space should be managed optimally.
Most gardeners use the soil in the greenhouse. If only one type of plant is grown inside, it is an effective solution. It is different story if plants with various soil requirements are being cared for in one tunnel. The greenhouse can be divided into sections, allocating spaces for garden boxes. Crops in suspended pots, mounted to the frame, is a viable alternative with steel polytunnels. However, this should not be implemented with PVC or aluminum constructions. Both materials are not resistant enough for this type of weight. It is also worth considering varieties and coordinated cultivation for every available site.
Plant care in a polytunnel
What to grow and what not to grow in a polytunnel? Most garden tunnels are used to cultivate fragile vegetables or flowers. These, being more vulnerable to damage, develop under cover. Resistant perennial plants should be sown outside, leaving the greenhouse for the more delicate ones. When planting, it is good to take into account dimensions of the fully grown crop, considering the width and height of the greenhouse.