Life in the Polytunnel

Some things sit on my to do list until it's too late to do them. This I find is an excellent way of clearing the list!

Cleaning the polytunnel was one such job, but out of the blue last week I summoned up the enthusiasm to undertake the yearly task. Another week and it would be too late as there would be too many plants in there to get to the polythene walls.

The outside is quite easy, though reaching the top is a challenge. The inside is more tricky, particularly the roof as everything drips back down in your face. This is one reason to do this on a cooler day too so the drops are not boiling hot.

I use Citrox on the inside, a natural disinfectant which contains extracts of citrus fruit. It is antibacterial and antifungal.

The difference between cleaned and not cleaned.

The polytunnel is the ideal place to work when it's cold and raining. On the other hand it is not the ideal place to work when it is sunny, temperatures rapidly escalating to 40+ degrees.

It provides a unique climate.

Ideal for a dust bath but 

all poultry are now excluded

The challenges:

No rain, so watering must be done manually. Extreme temperatures, meaning that dehydration can be astonishingly quick in trays of seedlings. Low night temperatures. Limited ventilation.

The advantages:

Protection from winds. Protection from sparrows, pigeons etc. Warm soil. Excellent light levels compared even to a windowsill or conservatory.

The classic use for a polytunnel is to grow what I refer to as Mediterranean crops. Peppers, aubergines, melons and tomatoes do particularly well. In fact for some of these it is the only way to guarantee a ripe crop by the end of the season. These are high value crops which earn their allocated space.

Early mangetout just about to come into flower.

Turnips and early potatoes.

But the space is not required by these crops year round. In early spring there is time to grow some early crops which wouldn't be possible outside for another couple of months. I squeeze in a crop of early potatoes, mangetout, turnips and carrots. All of these are harvested before the Mediterranean crops can go into the ground. Once things heat up the polytunnel becomes too hot for these cool weather crops. This year some of my turnips are already bolting (producing flowers in response to hot conditions, which often makes root crops tough and woody).

Polytunnel Plan, rotation year 6.

This plan is flexible. I don't grow all of these plants every year. 

Another really positive advantage of the polytunnel is as a place for raising seedlings. As I've alluded to seedlings growing in relatively small soil volumes such as seed trays or modules can easily die if the soil dries out. But this challenge is more than outweighed by the warm temperatures and in particular the light levels. I find that all but the most tender of seedlings can cope with dips in night time temperatures. If necessary they get the added protection of a cloche or fleece.

Raising seedlings in the polytunnel.

Some of these are ready to go outside just as soon as we get some rain.

One final use of the polytunnel is to hold young plants overwinter which have been started in the autumn. When light and temperature levels lift in early spring, these plants have a huge head start.

With the polytunnel all cleaned I decided to plant my tomato plants. The literature says to only plant tomatoes in the soil when the first flowers have appeared. I don't really know why you need to wait, so this year I have taken the risk and planted them before that time. Sometimes you just need to get things done when you can.

I grow many varieties of tomato of many shapes, sizes and colours. Last year's experiment of growing them up strings worked well. I actually use baling twine which is never in short supply on a smallholding and has a multitude of uses. I loop one end under the plant plugs and tie the other to the polytunnel frame. The tomatoes are planted quite deeply, up to their first true leaves, as they are capable of putting out extra roots from the buried stem.

I always grow too many from seed, just in case they fail, which they rarely do! And I always struggle not to plant too many. Any spares get given away to encourage others to grow their own food.

I can fit a couple of dozen plants down one side of the tunnel (actually half of one side). This year I have carrots down the other side as they grow brilliantly in the tunnel and are protected from carrot fly. I decided to double the tomato capacity by overplanting these with tomato plants. Hopefully they will grow together on different levels.