High Density Vegetable Growing

If you’re serious about vegetable production then your garden landscape plan could include a polytunnel, a giant version of a cloche that’s big enough to stand up in. Like a greenhouse, but significantly cheaper, this large tunnel of hoops covered in taut translucent plastic sheeting makes plants of all kinds grow faster and can seriously increase the production levels of the average vegetable plot.

Polytunnel – Good or Bad?

The polytunnel often evokes strong emotions. Commercially they are loved by farmers as they extend the growing season at both ends and are reckoned to have almost completely eradicated the diseases that affect berry crops in wet weather. They reduce the use of pesticides and the higher temperatures inside allow us to grow vegetables that wouldn’t normally survive in the UK.

But those against the polytunnel point out its two-fold effect on water levels. The higher temperature inside causes the soil to dry out so they require more watering. Secondly the tunnel itself can cause rain run-off problems because water can no longer soak into the ground where the polytunnel has been put up.

They can be quite bright to look at in summer and the wind can whistle through them in winter. Although you do not require planning permission to put one up it might be wise to put it somewhere where it won’t be too obvious to neighbours.

Building a Polytunnel into the Landscape Plan

If you decide that a polytunnel is right for you then your landscape plan will need to take it into account. Even the smallest is pretty big so you’ll need some space. You might also have to factor in some landscaping to screen it from neighbours.

A polytunnel should run from north to south so that no side gets overheated in the summer and the door obviously needs to be in the most convenient place. There’s nothing to stop you having a door in both ends but if you don’t, make sure there’s an adjustable opening at the end with no door to allow through ventilation.

Construction Requirements for the Landscape Plan

Assembling and installing a polytunnel will differ from manufacturer to manufacturer but there will be some basics that won’t differ. Polytunnels rarely have floors so the soil needs to be in good condition and completely free from weeds. Polytunnels will accelerate the growth of any plant and that includes weeds! You could also consider putting down mulch or a weed barrier in sheet form as a belt and braces tactic.

The plastic cover of a polytunnel will eventually deteriorate through the action of the sun, wind and rain. They are usually guaranteed to last for four or five years but many users report getting seven or even eight years out of them. Cover life can be extended by putting ‘anti-hot-spot’ tape over the tops of the supporting hoops. This lessens the heat build up at this traditional weak point and is reckoned to extend the life of the cover by a year.

Plan for Success

If you are unsure about whether or not to include a polytunnel in your garden landscape plan, see if you can find other people in your area who have put them up and ask them for advice. Failing that, have a look on the Internet, there are plenty of articles and examples there.