Posted on 08.07.2022 |
Added in Sheila May's Blog
One thing leads to another – Erecting the new polytunnel
So FINALLY after all these months of one thing leading to another, we are about to deal with the new polytunnel. To show you where it is going to go, I have positioned a bench on the patch of ground in the photo below. The paving stone you can see is where the entrance to the previous net tunnel was, clearly showing that we had to extend the area by another 5ft (almost 2m). You can see that we are part through deturfing the path alongside the line of Swiss Chard in front of the bench.
Site of new polytunnel 14 4 19:-
The new tunnel was going to be 20ft x12ft (6.1m x 3.66m) and having learned from putting up the original tunnel that it is REALLY difficult to get the plastic to lay flat over a tunnel that is on a steep slope, we tried hard to make the surface much flatter:-
However, because of time constraints (it was getting late in April and we needed to get the tomatoes into the polytunnel asap), and the fact we were still harvesting the Swiss Chard, we excavated the bare minimum of ground needed to site the tunnel, leaving the creating of the path round the poytunnel for later in the year. You may be able to see the mounds of soil the dumpy barrow has just deposited higher up the slope?
As you will have glimpsed in shots in the past two months of the finished polytunnel, it looks very different from the original. You may remember I said that one problem we discovered with the polytunnel we had was we always wanted more ventilation. I decided that I wanted the new tunnel to be mesh part way up the walls from the ground to give good ventilation, and then plastic up from there. This involves a completely different construction method to our original tunnel, as with a wholly plastic tunnel, you bury the hoops, AND the plastic in trenches round the polytunnel and back fill. With a mesh tunnel, or part-mesh tunnel, the hoops are set on “feet”, or baseplates, that are cemented/buried/bolted into the ground (depending on what surface you are trying to erect on.) Here you can see the first baseplate going in:-
In order to make a rectangle, and be sure of the site of all your baseplates you need two very high-tech bits of kit – a triangle you make yourself to size out of bits of batten, and two long pieces of string that you string from one corner diagonally to the other, and then measure each bit of string to see if they are the same length or not (if they are HURRAH it's a rectangle, if not, lots of rude words, and “finessing” is required, I leave it to your imagination how that worked out for us to begin with…..):-
The following shot shows the hoops gradually going in – and how close it is to the chard!:-
We also wanted sliding doors rather than conventional swing doors, to maximise growing space inside the tunnel. The following shot from 12 May shows how the back sliding door frame is created, and the wooden edging that we had to add at the base of the polytunnel to level up the site. As you can see, “level” in our context means that the side nearest the bottom of the slope has to be built up so that we don't have to dig another 30cm into the chalk hillside across the rest of the 12ft (3.66m) to get it level.
16 May, here you can see the front sliding door frame (a double width door) and the tensioning bars for the mesh all in place.
I decided that I wanted the mesh to be as high up the side of the polytunnel as possible – it comes as a 1m deep roll – so it is not quite a metre, to allow for the ends to be tensioned into their bars top and bottom. Here's the mesh fitted but not yet tensioned round half of the tunnel:-
17 May, the chard is sacrificed so we can get access to get the plastic over the tunnel:-
Then the plastic was slung over:-
To tension it you fix the plastic into the top of the bar that you tensioned the mesh into on one side of the polytunnel, pull it over the structure, and then you SWING on it on the other side to stretch it out before poking it into the tensioning bars on the other side. Really. Feet off the ground swinging! The manufacturers show an employee swinging from the plastic in a video on their website. Himself did try it to tension the plastic round the doors, but I was too chicken to take my feet off the ground! You need to pleat the ends into the door frame and attach. Here it is all cut to size on 20 May:-
Back sliding door fitted, (we should be on the Sewing Bee with that standard of pleating!):-
Another thing we had learned with the original polytunnel was that if you watered tomatoes in pots, even on trays, on a bare earth floor, weeds grew! So we wanted to put weed suppressing membrane down in the new tunnel. To do this, we had to flatten the ground and ram it flat – here he's just got to the end of the ramming process by the front doorframe on 27 May:-
Not a moment too soon – the very next day, I started planting up my tomatoes:-
Only a month late!! As you can see, they are quite big already, and bursting to get into their bigger pots. As you can imagine, they then romped away – here is a shot from 11 September showing the vines laden with fruit:-
I assumed that year they hadn't reached the height and vigour they used to in the old polytunnel because they went in late. However, the same thing happened the following year, with leaves getting yellower quicker, and the crop finishing earlier than I am used to. I eventually deduced that it was because unlike the old tunnel under the birch trees, this polytunnel was in full sun, so even with the added ventilation, the leaves were still frying in the more than 45 degree heat. I decided I would have to erect some shading. I assumed this would be something on the outside that I would put up for part of the year, (like a tall windbreak). When looking into some materials that I could use however, I discovered that I could buy something that looked just like the mesh at the bottom of the polytunnel, that I could attach inside the tunnel – and so that is what I did for the 2021 season. As you can see, here, (17 May 21), not only are the tomatoes all in situ already, the high-tech fixing mechanism is some bamboo canes and garden twine….
This certainly helped with the tomatoes growth and kept them healthier through the summer. Here's a shot through them on 15 September 21 showing much greener leaves, and lots of lovely tomatoes:-
Let us end with a view across the gravel garden on 25 July last year to show the star planting combination of the Yucca filamentosa in full flower, with the Hemerocallis fulva flowering behind it, and the Leucanthemum x superbum behind that. Also visible are two self-seeders – the Teasel (Dipsacus fullonum) behind the Yucca, and the Verbascum olympicum behind the Shasta daisies:-
The Shasta daisies are planted in the final bed of the gravel garden that I have yet to tell you about, so I shall do that later in the year. Next month I shall be showing you some of the flower variations in my self-sown hardy geraniums.