Thank you to Dorothy Searle for this article which featured in our Spring 2015 Newsletter.
My alpine house is only six feet square, but I have a lot more useful space in it than you would expect. Basically, it’s an ordinary aluminium-framed greenhouse, but the difference is in the brick base, which is also the outer wall of a low-level plunge bed. The inner wall, of the same brick, surrounds the path, so that the plunge-bed is U-shaped. The path itself is slightly lower than the ground outside, so that it’s easy to reach the plunge bed. There’s a step just inside the sliding door and another outside.
This is the MK2 version of the base, built with engineering bricks.
The first one, in my previous garden and beautifully built by my late husband, used ordinary house bricks, and they began to flake after a few years.
There’s another plunge bed above the first one, in the form of deep aluminium trays on legs. There are three units; the one across the end is five feet by two and the two at the sides are four feet by twenty inches. They were supplied by Two Wests, who call them ‘alpine benches’. The standard version has a shelf under the deep tray, but Two Wests modified them for me so that, instead, there are tie-bars at the bottom between the legs – directly under the edges of the units. The inner legs of the benches rest on the wall of the lower plunge bed, but the outer legs rest on little pillars made from bricks standing on end. There is room to stand (with care) on the inner wall to reach the roof for cleaning and for releasing trapped bumble bees.
Both plunge beds are filled with sand which is not so sharp that it hurts my hands but is not so soft that it stays excessively wet.
The greenhouse itself was chosen carefully: the centre panels at the end opposite the door and on each side couldn’t have diagonal struts, and the whole structure needed to be tall. There are six louvres in all – one above the benching and one below on each side and at the end. There are two roof vents, opened and closed automatically by thermostatic devices set to open at the lowest possible temperature. I had a suitable strip-light installed, but no heating; I find that I rarely need even to use bubble plastic insulation, but I do live in sub-tropical Southampton.
In practice, I grow mostly cyclamen and bulbs, arranging the plunged pots to suit their summer watering requirements; having three separate units on the top level makes this easier. Plants that want some shade go on the bottom level and those that love the sun on the top. The green watering can in the doorway seems to be a very efficient cat deterrent.