Polytunnels For Growing Vegetables & Fruit:

They can give your growing season a boost by as much as one month at the beginning of the season and also lengthen your season by up to the same period depending on the weather. But the best thing is they give your plants protection from late frosts and allow you to work on your vegetables in bad weather.

Your Polytunnels Size, Design And Installation:

Well this all comes back to you planning your venture, whether it be for your self sufficiency or a small or even large business venture. In your planning you must allow for companion planting and also allow extra space for the planting of certain plants which will attract insects which will attract predators of the pests which will try to attract your vegetables. So as a rule of thumb with this in mind you should add 25% to the size of polytunnel you require for your vegetables.

Make sure you purchase the tape or other protection which is applied to the steel to stop the plastic rubbing and eventually ripping as our Irish wind can make this situation worse if the protection isn't in place. Also plan where and how your polytunnel is to be sited by taking note of which direction the worst of the winds come from and also where the best sun traps are.

Do not site polytunnels in an area which water collects as water logged polytunnels are useless.

You will also need services like water and maybe electricity, so this must be taken into account and the expense of laying on these services must be added to your polytunnel costs.

If you intend to use a raised bed system then these should be installed and filled before erecting your polytunnel as this will be much easier done without the plastic covering installed taking note of where the plastic will be as you don't want to put anything inside your polytunnel which will end up poking through or rubbing on the plastic when this is applied to the frames. Also keep your raised beds the correct distance from the sides of your polytunnel otherwise your vegetables wont be able to grow upright as they will be crushed against the curve of the polytunnel. This is also important in choosing your polytunnel design as the best ones for growing along the sides are the ones with good height straight sides before the curve starts. This will allow you to grow tall plants like beans all along the sides of your polytunnel.

Polytunnels can get very hot and very dry in the summer months so your watering system should be well thought out before you start installing other equipment inside the polytunnel and not after, so make a plan before you purchase anything of what you intend to grow in there and then build your whole system around that plan.

You do not want your water system to freeze up in the winter and spend each spring digging up pipes and having to start repairing all your pipe work. Bury the water pipes to your polytunnel at least 18" deep and then either insert a stand pipe inside the polytunnel or a ground trickle water system with pipe work lying along the surface of your beds. Vegetables in a polytunnel could do with a good soaking to knock any pests off their foliage.

Ventilation in polytunnels is critical because on hot sunny days the temperature inside goes sky high and if not too hot to work in it could also be too hot for your vegetables. So as well as the front or main door it is best to have a back door as well so the two can be open on those hotter days and ventilate the polytunnel. It is also a healthy thing to do so any pests or diseases can be naturally ventilated away out of your polytunnel.

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