I bought my two greenhouse nearly 10 years ago, second hand off eBay. I have a "propagating house" 10' x 12' and a "growing house" 10' x 30'.
I've been very happy with them, never thought I would "need a bigger one" ... until now!!
... I have a couple of issues:
Overwintering stuff is a chore. I tend to have lots of plants in pots, growing on, which although probably hardy do benefit from not getting sopping wet being stood outside, and then their rootball freezes solid. So I squeeze them into whatever covered space I can find, and watering them in the early Spring is haphazard. It would be SO much easier just to stand pots on beds in the vegetable plot that have finished cropping in, say, October ready for the winter. I also have some tender things, a large Orangery that I can store the bigger things in, but those that are marginal I'll prefer to just "chuck" in the greenhouse.
Box Overwintering
Then there are crops that just need some season-extension, in addition to things that need more heat like the Tomatoes, Cucumbers, Melons, Peppers and Aubergines which I grow in my Cropping House. I already use part of the cropping house to grow Sweetcorn and Dwarf French Beans for an early crop, and Chard and Lambs Lettuce for overwintering, but it would be nice to plant Potatoes and Beans early and not have to worry about a late frost. I used to plant "early-ish" and be out at night with a torch covering them up with fleece ... but I grew tired of that, so now I plant a few early Potatoes in containers but the rest are planted out late enough to be sure that they will not be above ground until frosts have finished. So I miss out on decent early crops.
Lastly, there is my heavy, clay, soil which is impossible to get onto early in the season, particularly in a wet season like this (and last year too).
So I have been thinking for some time that I should perhaps get a multi-span polytunnel. But I don't really want to "force" my Summer crops, just to keep the winter rain off them, and any late frosts and thus I need really good ventilation in the Summer - I might want to keep some heat in at night, but try to limit heat-gain during the day - and I figure that would be hard with a polytunnel.
So I decided to cover the whole vegetable plot in glass :shock:
Commercial Greenhouses go for next to nothing on eBay, because of the effort to take them down, and put them back up. But I reckon it represents a really cost effective purchase. So I have bought a couple (wasn't sure one would be big enough!) which will cover my whole vegetable patch which is around 600 sq.m. that included a couple of round corrugated / lined rain water tanks.
Hope this is going to prove to be a good idea! swapping outdoor growing for protected growing, as I will have to do 100% of the irrigation and no doubt have more issues combating bugs. I figure that I will solve the irrigation with leaky hose as I already use that on at least half my vegetable crops, so ramping that up to 100% won't be hard, and I will use my stored rainwater for irrigation (I already have the whole garden plumbed with 32mm MDPE for irrigation).
But I'm starting to get cold feet!
Here's my sums:
I reckon it will take two people 2 weeks to take down a 60' x 40' glasshouse. The ones I have bought are substantial - made by the, sadly now defunct, Robinsons of Winchester - not the lightest tin structures that can possibly be made and which I see been erected on the Fens (known as Venlo?). They have full end-to-end ridge ventilation which can be opened almost to the vertical; Glazing bars screwed on (stainless screws), all glass is 2' square. Very few different types of parts - its all very modular. Needs some tools, which I already had most of, and the hire of some things - like a cherry picker / Genie lift which makes getting the roof down easy. Then the hire of a flatbed to get the bigger bits back, and the cost of either the commute petrol, or a B&B. So basically I reckon that a couple could take a fortnights holiday and disassemble one and get it back to base. Then put it back up over time / winter, all for the cost of perhaps £ 500 - £ 1,000 hire. I saw one commercial glasshouse, sadly too far away from me, sell for £ 1.51 (which I took to be the second bid on eBay - which is to say that the first person bid 99p and was not prepared to pay a penny more!!). Many of them get no bids at all ... but perhaps no one is as daft as I am? :mrgreen:
If you have any thoughts I would appreciate hearing them, thanks.
