These days with very unpredictable weather it is good to have an alternative and be more in control of your growing conditions.
On a very small scale most of us use the same technology (principal) as a polytunnel when we cover a seed tray with a sheet of glass, put a clear plastic bag over soft wood cuttings or use an empty plastic bottle to protect seedlings . Whenever we do that, we create a micro climate around the plants, seedlings or seeds. The same applies when we use cloth and hoops to cover and protect crops.
The reason for growing under cover is to protect from cold weather ,wind and possible predators and create heat and shelter. It will extent the growing season because you can put the seeds out long before the soil has warmed up and also will protect sensitive plants from undesirable weather.
Cold frames are really mini Poly tunnels or green houses. Most people with green houses use them mainly for hot climate plants like tomatoes but a poly tunnel can be much larger and doesn’t cost the earth. IF you want to make the most of the poly tunnel you don’t use it just for crops which like a hot climate but also to start seedlings in pots and grow salad leaves throughout the seasons as well as having new potatoes in December or plant your peas in autumn to harvest long before anybody else does.
So far we have had a bumper crop of French climbing beans and are looking forward to some tasty sweet corn. The cucumbers are doing well and even peppers and aubergine are ripening at the moment. Some people also have strawberries growing in gutters and melons trailing along.
It all depends how big the poly tunnel is and how inventive you are.
Needless to say that by growing lots of crops on a small space you need to add nutrients to your soil to keep it healthy. So far comfrey, nettles and applying horsetail tea as antifungal treatment proofed sufficient to keep all our crops healthy.
As a biodynamic grower I also used the biodynamic preparations more often than I do on the outside.
For more info on Polytunnels go to www.firsttunnels.co.uk
For more info on biodynamic preparations see website or go to www.biodynamic.org.uk
The down side is watering and ventilation. IF main water is accessible, lots of options are available but if you need to use rain water you need to be a bit more inventive.
We came up with a new idea, which is still on trial! (so watch the space!). We attached plastic guttering to the poly tunnel at ground level, slightly angled to collect the rainwater running off the plastic. (use repair tape to attach plastic guttering ). The collected rainwater runs into a waste pipe which runs underneath the polytunnel and has holes drilled into it to spread the water.
That way, the rain water will be below the roots and make them grow down rather stay on the surface . IF it doesn’t rain, I recommend a good soaking rather than sprinkling a bit of water around which needs doing on a daily base.
Anyway, it is our first season with our Poly tunnel and we will report how the rain water system works.