Gardening is a popular pastime, and yet many experience difficulty depending on the season and location. Greenhouses and polytunnels provide the perfect solution for growing plants, flowers and vegetables. They offer control over the environment, enabling gardeners to extend growing seasons, protect plants from extreme temperatures and pests, and give plants the best chance of thriving. Using greenhouses and polytunnels can take the frustration out of gardening and allow gardeners to be creative and experimental, while still achieving great results. With the right knowledge and setup, these structures can help gardeners to produce healthy and abundant harvests all year round.
What are greenhouses and polytunnels?
Greenhouses and polytunnels are covered structures used for growing plants and vegetables. They are suitable for growing plants and vegetables year-round, no matter the climate or the season. Greenhouses and polytunnels can extend the growing season by providing a controlled environment for plants, free from extreme temperatures. Greenhouses and polytunnels can be used on their own, or alongside other gardening techniques, such as gardening indoors or in a raised bed. Greenhouses are glazed structures, allowing light to enter and warm air to escape. They are usually built from wood, metal, polycarbonate panels or a combination of these materials. Polytunnels are typically opaque, protecting from extreme temperatures, but not from light. They are made from polyethylene, polypropylene or polyester. Polytunnels are often used in vegetable growing.
Benefits of greenhouses and polytunnels
The benefits of using greenhouses and polytunnels are as follows:
Extending the growing season: Greenhouses and polytunnels allow gardeners to extend their growing season, enabling them to get a head start on the growing season, and to continue harvesting plants and vegetables during the cooler months.
Growing during unusual weather: Greenhouses and polytunnels allow gardeners to continue growing during extreme weather, such as drought or frost, protecting plants from these adverse conditions.
Protection from pests and diseases: Greenhouses and polytunnels protect plants from pests and diseases, including weeds, rodents, insects and diseases.
Growing in less suitable locations: Greenhouses and polytunnels can be used in almost any location, including difficult or less suitable areas, such as balconies, rooftops or gardens with limited space.
Vegetable growing: Greenhouses and polytunnels can be used for vegetable growing, helping gardeners to maximize their harvest and enabling them to grow crops earlier in the year.
Flowers: Growing flowers using greenhouses and polytunnels enables gardeners to create beautiful indoor displays while extending the growing season outdoors.
Plant research and experiments: Greenhouses and polytunnels provide a controlled environment, allowing gardeners to experiment with different growing techniques, including hydroponics and aquaponics.
Plant research and experiments: Greenhouses and polytunnels provide a controlled environment, allowing gardeners to experiment with different growing techniques, including hydroponics and aquaponics.
How to choose the right greenhouse or polytunnel
Before purchasing a greenhouse or polytunnel, it is important to consider the following:
Growing area: The growing space available will determine the size of the greenhouse or polytunnel needed.
Materials: The materials used in constructing the greenhouse or polytunnel will affect the cost, lifespan and appearance.
Roof: The roof will affect the amount of light entering the greenhouse or polytunnel, and the amount of heat retained.
Floor: The flooring material will affect drainage and the ease of cleaning.
Ventilation: The amount of ventilation provided will affect the number of pests and diseases, and the amount of water retained.
Cost: The cost will depend on the materials used, the size and whether it is pre-assembled or not.
Location: The location of the greenhouse or polytunnel will affect how much light it receives, and the temperature.
How to set up your greenhouse or polytunnel
Before setting up your greenhouse or polytunnel, it is important to choose a suitable location. It should be protected from strong winds, but still receive enough sunlight. The greenhouse or polytunnel should also be accessible to the gardening tools used. To set up a greenhouse or polytunnel, follow these steps:
Mark out the location: To ensure the greenhouse or polytunnel is placed in the right place, first mark out the location using wooden posts, bricks or string.
Prepare the ground: The ground should be level and well-drained, so it doesn’t overflow with water. Add a thick layer of gravel to improve drainage.
Build the structure: Build the structure using wooden posts, bricks or a combination of these materials. If using wooden posts, they should be treated against rot, otherwise, they will need replacing regularly.
Add the lining: Add the lining to the structure, attaching it at the top with cable ties. Suitability will depend on the greenhouse or polytunnel.
Add the doors: Add the doors and windows, and attach the roof.
Add extra supports: If a wall is sloping, add a support to prevent it from falling over.
Add a floor: Finally, add a floor to protect the ground from rot and to make cleaning easier.
Tips for growing in a greenhouse or polytunnel
When growing in a greenhouse or polytunnel, follow these tips:
Use a balanced fertilizer: Use a balanced fertilizer, or add compost to the soil every few months, to keep plants healthy and growing vigorously.
Harvest when fully grown: Harvest plants when they are fully grown and have ample time to ripen, to get the best results.
Rotate plants: Rotate the plants regularly to reduce the risk of disease.
Control pests: Grow plants resistant to pests, or use natural pest control methods, to keep pests at bay.
Harvest rainwater: Harvest rainwater to water plants and soil, especially during dry spells.
Harvest rainwater: Harvest rainwater to water plants and soil, especially during dry spells.
Manage water: Water plants and soil when dry, but avoid over-watering to prevent disease.
Use plant supports: Use plant supports, such as pea netting and twine, to protect plants from pests and diseases.
Protect from extreme temperatures: Protect plants from extreme temperatures, especially during hot weather, by covering them with a light fabric, such as muslin.
Controlling the environment in a greenhouse or polytunnel
It is important to control the environment in the greenhouse or polytunnel to create the best growing environment. To control the environment, follow these steps:
Assess the location: Assess the location where the greenhouse or polytunnel will be built, to ensure it gets enough sunlight.
Set up the structure: Build the structure using wooden posts, bricks or a combination of these materials. If using wooden posts, they should be treated against rot, otherwise they will need replacing regularly.
Add the lining: Add the lining to the structure, attaching it at the top with cable ties. Suitability will depend on the greenhouse or polytunnel.
Add the doors: Add the doors and windows, and attach the roof.
Add extra supports: If a wall is sloping, add a support to prevent it from falling over.
Add a floor: Finally, add a floor to protect the ground from rot and to make cleaning easier.
Common pests and diseases in greenhouses and polytunnels
When growing plants in greenhouses or polytunnels, it is important to identify the common pests and diseases that could affect your plants. It is also important to keep in mind that not all pests will be visible, so it is important to regularly check your plants to spot any problems early. Always follow recommended pest control practices to prevent problems as much as possible.