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Yet More Greenhouse Building

Today’s plan was to get the greenhouse finished but that wasn’t to be. We got started mid-morning with me drilling some holes in the base so I can bolt it down to the slabs. Although it will be very heavy once the glass is in, never underestimate the power of the wind.

I remember telling a plotholder that he needed to fix his greenhouse down and being sent off with a flea in my ear as he explained how heavy it was with the glass. One storm later he had a pile of broken glass and twisted aluminium and I manfully resisted the urge to say ‘told you so’.

Val made a start putting the rubber stripping on the glazing bars. What a job! It’s not particularly difficult, just fiddly and boring. By end of the day she’d finished all but the bars in the roof. My neighbour Clive came down again and put the opening lights together.

The first one took a bit of time, but the next three were done in a trice. It was then we realised we needed an extra nut and bolt in eight of the glazing bars. So undo from the ridge, loosen the bracket nuts and slip an extra bolt down the channel in the bar. Sounds easy, took the best part of an hour!

Clive got one of the doors together but by now the sun was setting and it was getting chilly. It doesn’t help that my cold is lying on my chest now so everything is punctuated by coughing fits. However, it’s got to be finished before we get some windy weather so nothing to do but plod on.

Greenhouse Design

I was asked “Could you explain your reasoning for the solid (slabbed) base rather than leaving beds for direct planting?” in a comment on my last entry on constructing the greenhouse

Primarily, I didn’t have a choice. The base has to be level and the site is quite sloping. So we dug in on the high side and built a wall on the low. Filled the interior with rubble and slate waste (which is cheap as chips here) before slabbing over.

In my last large greenhouse I had borders around the edges and used it for growing tomatoes, peppers etc but the small greenhouse only had one soil border, the rest being slabbed and using benching for seedlings and pot grown. The big benefit to soil borders is that, like the ground, they hold a lot of moisture so don’t need watering as frequently. That’s useful if you don’t have an irrigation system or don’t visit the plot too frequently.

The drawback with soil borders is that the soil gets tired, by which I mean the nutrients become exhausted and pests and disease can build up. The answer here is to dig out the top six inches (at least) of soil and replace with fresh compost. This can be quite a task, moving over a cubic yard of soil in a confined space where an enthusiastic swing of the spade breaks the glass.

I’ve also found that peppers and cucumbers can do better in pots. Restricting their root growth seems to push them more to fruiting than foliage. The plant that you really have to watch with watering is the tomato. Irregular watering, especially allowing the plant to dry to drooping point almost guarantees blossom end rot.

Most grow-bags fail to provide enough compost or water reservoir for tomatoes when used as directed but inserting a large bottomless pot into the bag and growing in that does work a treat. At the end of the season the bags and compost can be added to the plot as soil improver quite easily.

Another option I considered was to build a long box or similar filled with compost for the tomatoes but as we’re here to water every day and I know the extended grow-bag system works well it seems like a lot of extra work for no real benefit.

You can’t garden without doing some work, but there’s no need to make a rod for your back.

Posted in Allotment Garden Diary
2 comments on “Yet More Greenhouse Building
  1. graham lindley says:

    here just a quick thing i discovered , i gave up using grow bags and borders , visit your local supermarket and ask if they can sell u the buckets the fresh flowers come in , drill a few holes in the base fill with compost and water retention crystals and plant aways , i always use this method now for tomatoes , cucumbers , peppers and chile , at the end of the growing season empty buckets on to plot , store , wash well and start again, i purchaced 50 buckets for £5

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