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Growing Vegetables in a Polytunnel

Updated: Nov 18, 2020

What is a Polytunnel

  • Polytunnel (also known as a hoophouse, polyhouse, hoop greenhouse, or grow tunnel) is generally made from steel and is covered polythene, poly for short (heavy plastic)

  • They are usually semi-circular and elongated in shape, however square polytunnels do exist

  • The polytunnel is heated by incoming rays from the sun

    • The interior heats up due to the fact that the sun is warming the soil, plants, and anything else in the polytunnel faster than the heat can escape

    • Heat is retained by the objects in the structure and by the walls

      • The poly cover traps the heat inside resulting in an increase in temperature

  • The poly that is used is specific to the job

    • It is manufactured to resist UV rays and can have a thermal, anti fog (anti condensation) cover to prevents moisture dripping down

  • Double layer polytunnels use a blower fan to inflate the area between the layers

    • This keeps the poly tight, and creates an installation barrier

  • Temperature and humidity inside a polytunnel can be controlled by equipment such as fans inside the structure or by opening and closing doors, vents, windows, (whichever your structure may have)

    • Some polytunnels feature roll up sides

  • Polytunnels are much cheaper to build than greenhouses and they sure much of the same purpose, protecting plants from the elements

    • They provide crop protection from: animals, wind, rain, heat, cold, sunlight

  • Polytunnels create a micro-environment that provides higher humidity and temperatures, allowing the growth of many fruits and vegetables even when they are not necessarily in season

  • Unlike a greenhouse they can easily be taken down and moved to a different location

"Polytunnel gardening extends the growing season because it warms earlier in spring and stays warmer longer in the fall"

Why use a Polytunnel

  • Polytunnel can be used to produce a wide range of plants for consumption or decoration

    • In milder climate growing season can extend into the winter months

  • A polytunnel can be used to increase heat and humidity for plants that require it, as well as allow gardeners to grow crops that otherwise would be difficult to grow in their region

  • Disadvantages

    • Irrigation must be set up for watering

    • Although they can keep pests out, problems can build quickly in the enclosed space

What to Plant in a Polytunnel

  • Tomatoes

  • Peppers

  • Eggplant

  • Asian greens

  • Salad greens

  • Peas

  • Cauliflower

  • Cabbage

  • Potatoes

  • Onions

  • Radish

  • Carrots

  • Cucumbers

  • Strawberries

"We recommend planting raised beds inside a polytunnel, this avoids having to walk on soil to get to plants, Raised beds also allow you to build soil to improve growing quality"

Looking After a Polytunnel and its Plants

  • Instal a thermometer so you can track the temperature fluctuation

  • Insure that dors, windows, vents are open when it gets really hot out so that the interior does not overheat and harm plants

  • Structure should be washed inside and outside once per year to get rid of any dust/dirt build up

    • Want to ensure the maximum amount of light is able to get through poly

  • Poly layers should last 3 to 5 (some lasts up to 10) years before needing replaced

  • Be use to patch holes in poly before they get to big

  • Keeping plants as healthy as possible is best defence against pests and disease

    • Make sure polytunnel has good airflow and ventilation

      • Instal fans and open doors, windows and vents during nice weather

    • Check plants regularly and address any pest or disease problem asap.

    • Use crop rotation practices

    • Do not over crowd plants as this can prevent adequate airflow around plants

We highly recommend a poly tunnel to extend your growing season! Below are some quick order to your door, ways to get started!

And lastly, we are so happy you have decided to start your gardening journey! We know your going to be hooked when you harvest your first homegrown vegetable. If you are new to veggie gardening and not sure where to start?

You can get a full complete newbie guide here -> CLICK HERE


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