Pros & Cons of a Big Polytunnel

Polytunnels come in a huge range of sizes. Ours is a bit on the big side for a family of four (21 x 40ft) and there are pros and cons to this. With our inclement Irish climate having a lot of space under plastic is great because many vegetables that would just be drowned outside manage to flourish. The extra few degrees on sunny days really helps to boost ripening and growing rates of plants in the tunnel. Extending the length of the growing season is invaluable adding a month or two to either side of the normal time available. By choosing the varieties carefully there can be crops available year round from the tunnel (winter greens, chard, year round salads etc). Last but not least, having a dry wind free spot to work away in the garden is fantastic, even when it's lashing rain you can still happily potter in the polytunnel.

The downside is that there is a lot of space to manage and keep under control. This need not be too difficult. When the tunnel is first erected there's no need to get all the beds into commission in the first season. By using mulching, some areas can be left dormant for a year or two so the task isn't too daunting. As the years go by dormant beds can be sewn with green manure which will prevent weeds taking over and can have an advantage over mulching in that it doesn't become a slug hotel. The only other downside of a large tunnel is the annual cleaning of the plastic. Over winter and autumn a green algae grows on the plastic and cuts out a significant amount of light so it's important to clean it off before spring. This means wet work with chilly hands. Getting a few folk in to help can boost the moral and make it a social event. When the job is done hot chocolates all round go down a treat.

Comments

[cc in California]

Another advantage of the poly greenhouse is that you can start seeds much earlier in its protected microclimate. Is that beets in the picture?

[Sue]

I've got a slightly smaller one 12ft x 25ft and am finding it brilliant, we've just harvested the last of our cucumbers and we have been living off the salad crops from it all summer, and as you say gardening on a wet and windy day is fantastic when you are under plastic!!

Sue xx

[Allotment Blogger]

Oh this is very interesting as our allotment site is constantly debating the pros and cons of having a polytunnel for communal use. Thank you for sharing this information, it will really help our discussions!

[Ben Short]

Hello. Do you leave a gap between the beds and the inside of the tunnel?

[Rebecca (Sallygardens Smallholding author)]

Hi there, yes they are beets, boltardy variety.

No we don't leave a gap between the plastic and the side beds.

[jg]

Hi, I will soon have a 30 X 14 Polytunnel, I wont be able to use all the space in the first season so I am wondering what green manure is and where I get it.
What site would you suggest for good seeds, planters and compost.

[Rebecca (Sallygardens Smallholding author)]

Try the Organic Centre, Rossinver, Ireland, for green manure seed packs. Green manure are plants which are grown for a certain period, then dug back into the soil as a form of soil preservation and fertiliser.

[Andy]

Does it cast much shade. If I were to place one on my allotment would it affect my neighbour. Say with a 12 x 20 ft

[medieval clothing]

oh that's great, with that you could also help fight global warming. thats an awesome thought of yours! anyways, i like your banner

[soldes air max]

Pruebe el Centro Orgánico, Rossinver, Irlanda, para los paquetes de abonos verdes de semillas. El abono verde son plantas que se cultivan durante un período determinado, y luego cavar de nuevo en el suelo como una forma de conservación de suelos y fertilizantes.