Whether we are growing salads, vegetables, herbs or exotic flowers, a polytunnel is an invaluable accessory for our growing needs and requirements. The advantage that this gardening enclosure will give us cannot be underestimated as it will cater for all or most of our starting and seedling crops and plants, before we decide to plant outside in our raised beds or row gardens. Regardless of what the weather is doing outside, we can begin our growing season in this envoirnment and that will bring serious benefits for our plants and vegetables harvest later on in the year.
Indeed, it need not be springtime when we can get the most value from polytunnels as we can use these pretty much nearly all year round. Depending on how severe the winters are, if we have serious snowfall and hard cold nightly frosts, then nothing willl happen until that type of climate has passed. Other than those conditions, we can practically use this enclosure throughout the year. The beauty about gardening with polytunnels is that they create a microclimate envoirnment and that renders the inside conditions very conducive for growing all or most varieties of vegetables, salads or herbs.
How big should a polytunnel be;
The overriding factor to take into consideration when thinking of purchasing a polytunnel is its dimensions. Firstly we need the polytunnel to be big enough height wise, so that we can work comfortably inside these, without having to stoop or bend. Our next priority is the quality or grade of the polytunnel polythene which will dictate the price that we pay for these accessories. A good quality polytunnel will cost that bit extra, but we need to remember that this enclosure will need to be able to withstand different weather extremes, ie, severe heat and cold, strong winds and also some frost and snow from time to time. The frame of this construction also needs to be strong, robust, durable and rustproof and all of those those elements need to be factored into our plans. The actual size will also be governed by our budget, that said, expect to pay anything from $150 upwards for a reasonably sized average garden polytunnel.
What else to look for in a polytunnel;
The other ingredients of a good quality tunnel would be that we have back and front doors for good quality aeration and ventelation. If we were able to have side windows also, that would be a bonus as this would help with ventelation and light. Powder coated steel tubing is the standard expected requirement for the structure of these tunnels and that would enable easy fitting and assembly. As for the doors of the tunnel, some have a zippered device for sealing the tunnel, but if we were able to get timber frames and doors, that would make our poly construction a stronger, sturdier option, for obvious reasons. One other idea worth mentioning and that is if we could bury 6-8 inches of the poythene cover underground at the sides and ends, that would prevent unwanted critters like rats, moles etc etc. from getting into our warm cosy enclosure.
The length of the tunnel itself should start at 15 ft, height wise, I would be looking at 7 ft at the centre and would look for a width of 10ft. Those dimensions would be ideal for a first timer or beginner and would give us adequate room for all our planting needs. With a width of 10 ft or more, that would enable or allow us to have a centre aisle of 2-3 ft, which would be plenty for wheelbarrow access, if required. The design could be pitched if needed, but the round design or shape is the more favoured option for these constructions as it allows the wind to pass over these seamlessly. The idea of having two doors or exits, is to allow the air to pass through the tunnel and prevent it from getting stale in one corner, if we had only the one exit door.
The inside of a polytunnel;
This is where the magic happens and as we have mentioned earlier, we have a warm humid microclimate in here which will greatly enhance and expediate the starting and growing of our vegetable seeds and seedlings. As soon as the polytunnel has been erected and fully assembled the next step is to plan the layout of our enclosure. We are talking about shelving and possible indoor raised beds or perhaps some elevated raised beds, which would greatly enhance our indoor gardening and growing experience. Another idea would be to attach some crop support bars from the inside frame of the polytunnel, which would enable us to grow climbing plants or vegetables like peas, tomatoes or peppers and so on. ( I have seen people use these polytunnels to dry and air their laundry and washing, but that’s for another day )
Costs and maintenance of polytunnels;
We have mentioned a figure of upwards of $150, but this is the price of a good solid roomy unit, which would be a great starting investment. We can go lower but expect the size and quality to be inferior to what we have discussed earlier. Can we get secondhand tunnels…absolutely, but we could be either lucky or unlucky with this option. There is no replacement or returns policy with the secondhand route, however, we could strike a good deal if we shopped around and knew where to look. These polytunnels are available to purchase at all garden centres, hardware outlets and also online. The online version comes with free shipping, a set of easy to follow assembly instructions and a guarantee of parts and wear, in most cases.
The polytunnel cover should last for 5 yrs or more and does so, if we are living in a sheltered location. The wind is the greatest enemy of these enclosures, so it’s always best to locate or erect these in a sheltered area. Every year, it would pay us to wash down the outside and insides of our poly canopy, thus getting rid of any unwanted moss or green algae lichens and this exercise would allow more sunlight to penetrate into the tunnel enclosure. The soil needs replenishing from year to year and as always remember to rotate crops and veggies, as this method would prevent disease and blight from getting a foothold in our soil. As ever feel free to contact us via, the comments section below, with any issues or queries and we will respond in due course.