raised beds or pots and bags in polytunnel?

[nat'n'lou]

Hi,
I was just pondering the pro's n cons of either raised beds or pots n growbags in a polytunnel.
Some friends of ours have the same tunnel that we have and built a raised bed around the inside edge whilst we opted for pots and growbags last year.
To me it looked like they had a lot more in the same space and their yields seemed bigger but that could have been down to me being less green -fingered
I was just wondering what folks thought about any pro's n cons?

Cheers Nat

[Kristen]

I grow in the ground in my cropping greenhouse. Watering is much easier than containers (when I had Tomatoes in containers they needed watering three times a day in mid Summer ...) Irrigation is easy with leaky hose - much more tricky to automate irrigation of containers (if you want to be able to go away for the weekend, for example)

I replace the soil each year using a mixture of compost heap and rotted manure. The compost heap is pretty rough material (I'm not a composting fanatic, not enough time or energy!) but it is gorgeous when it comes out of the greenhouse at the end of the year. Unlike my clay soil it is not heavy to work / barrow about.

The beds in my greenhouse are lowered, rather than raised, to provide maximum cropping height to the roof. I reckon I can get at least one extra truss on my Tomatoes as a consequence.

[nat'n'lou]

Thanks Kristen
I must admit watering was.a bit of a pain... mmmmmmm leaky hose irrigation, this is something I need to explore..
Cheers Nat

[marchogaeth]

I've got beds. This was to raise my plants above what can be an evil winter water table as I grow all year round. I haven't actually completely replaced any bed soil yet (Season 4) but I do tend to chuck compost/manure, chopped nettles/comfrey around and as beds get high or I need to fill pots I scoop it out of there and then top up again. I am however, constantly aware that one day a bed will probably start to fail at which point I will replace it down to a good depth. I can't drip water because my water is gravity fed from a stream so can be very grubby (I am allowed to do this). However, I would not want to because my aim is, actually to keep the soil's surface dry so humidity is low - I've never had blight in the tunnel and I don't want it - I am in a very high risk area. I water through bottles/bottle towers sunk into the beds and mist things like cucumbers (although I fully accept that they probably under perform as a result so I so an extra one).

Also, I am on site every day because it's my garden not an allotment.

I have tried using bags on beds and have been disappointed, even when I have really slashed the bottoms to let the roots through. I'm just not sure why.

Do check out this thread. It's not all me! There are lots of ideas there and it would be really good to see it more active. Check out the companion thread as well (Link in post one) as we need to share our mistakes as well as our successes. Also if you put up a picture of your space you will always be able to link to it when asking for help which is just as important as your location when asking for advice.

Pob lwc!

[nat'n'lou]

Thanks for this marchogaeth
I will upload some pics as I'm sure we didn't really utilise the space to its full potential and thanks for linking to the other threads.. I will explore them covertly whilst under the guise of working in the morning
Cheers Nat

[nat'n'lou]

Hi,
This weekend I will be putting raised beds in my polytunne. It's 4m x 2m with a small slab path up the middle 3m long so I was thinking of building a 'u' shaped bed but how deep do I make them? Our local timber merchant has got some 20mm x 150mm treated but do I go for 300mm or 450mm(12" or 18")
Also the floor is 20 mm gravel do I put weed fabric in the beds before filling or will it be okay to just fill on top of the grave??
Cheers Nat

[Sarico]

I grow in the ground in my cropping greenhouse. Watering is much easier than containers (when I had Tomatoes in containers they needed watering three times a day in mid Summer ...) Irrigation is easy with leaky hose - much more tricky to automate irrigation of containers (if you want to be able to go away for the weekend, for example)

I replace the soil each year using a mixture of compost heap and rotted manure. The compost heap is pretty rough material (I'm not a composting fanatic, not enough time or energy!) but it is gorgeous when it comes out of the greenhouse at the end of the year. Unlike my clay soil it is not heavy to work / barrow about.

The beds in my greenhouse are lowered, rather than raised, to provide maximum cropping height to the roof. I reckon I can get at least one extra truss on my Tomatoes as a consequence.

I'm interested in this considered that I have a greenhouse at the plot. Is my first year and I want to plant in be. So is like a big planter bit open at the bottom and every year you just empty it. Maybe ill give a go one side I'm bed and other half in container.

[Jungle Jane]

If you're putting it on top of gravel/weed fabric,roots won't grow through it,so I'd go for 18"deep or do you want things to grow deeper in the ground under the gravel,without a weed barrier,then it wouldn't need to be as high as 18"? Some plants like depth,Tomatoes like to be planted deep,depends what you want to grow?

[marchogaeth]

I think it's like Jane says. When I made mine, we sunk the paths by digging the top soil out of them and using it to fill the beds. My beds are only about 12" deep on top of the soil but I don't have any barrier to the roots. What I cam to say is that I have had minimum weed problem. If you keep on top of any weeds in the tunnel they soon become a thing of the past. If you really want a weed barrier but don't think you'll need one for ever one of the best things I have used is newspaper. I made an outside muck heap for my courgettes etc. I dug down about 2" and use the top soil in the tunnel, I then lined the bed with wet newspaper. I used the local and opened each issue flat. There were just no weeds coming through that and it was on grass, nettles and creeping buttercups. The bed is still clean even though the paper must have rotted and the roots gone through it ages ago.

You could also consider doing 12" now and if it's a bit thin, put another row on next winter!

[Kristen]

Hi,
This weekend I will be putting raised beds in my polytunne. It's 4m x 2m with a small slab path up the middle 3m long so I was thinking of building a 'u' shaped bed but how deep do I make them? Also the floor is 20 mm gravel do I put weed fabric in the beds before filling or will it be okay to just fill on top of the grave??

What's under the gravel? If it is just soil I'd be inclinded to remove the gravel and plant in the soil. If you put a membrane down, and soil / compost on top, you will be creating a "container". I find it much easier to grow in the greenhouse soil - much less hassle with watering, with containers there are much more severe issues with drying out and water logging.

You might get some weeds in Year One, but unlike outdoors you won't get weed seeds blowing in, plus the hot and dry conditions in the greenhouse will mean that less weed seeds germinate, and personally I've never known it to be a problem. (It probably was in Year One but I can't remember that far back!)

I don't have raised beds in my greenhouse, in fact I lowered them - to get more cropping height (e.g. for Tomatoes & Cucumbers) to the roof


Replacing soil (done annually, although that frequency probably isn't necessary) with 50:50 compost heap & rotted manure

#
Planting Tomatoes


The "lowered" beds - for more cropping height

[nat'n'lou]

Thanks for all the input folks, I will probably dig out the gravel because it's fairly decent soil underneath. We put weed fabric and then gravel originally to level out the ground as we intended to grow in growbags but I can now see the benefits of growing directly into the soil. We have plans to grow a multitude of different crops year round ( just waiting for the how to grow fruit and veg in a polytunnel book)
Thanks for all the advice folks and I will post some pics of my labours
Cheers Nat