Alpine house: Construction of sandtables

[Michael Mauser]

Hello,

as promissed I want to give some more impressions of our botanical garden in Tübingen and a little 'how-to-do' (better: How we do) the cultivation of Dionysias.

The first post is about the construction of our sandbeds in the propagation house.
We had some advice and ideas from Michael Kammerlander, perhaps the best Dionysia grower in Germany (beside some unbelievable Irises and other bulbs). In 2005 we visited him the first time and had a look at his houses, the construction of the tables, his tufa-wall and shading-system.

This is the plan how he build his tables - an easy not expensive way made of wood and pondliner:


As we wanted to build the tables a strong way we decided to use aluminium (this winter we had the possibility to rebuilt the interiour of an old propagationhouse, so I took the chance to take a lot of photos).



The aluminium is 8mm thick so that a skilful craftsman (not me!) can drill in holes for screws.

With a good saw the aluminium sheet was cut in size.


The sideparts have to be fixed to drill the holes in the right way.



As said it's not so easy to drill in 8mm thick material.


but our master of tools is just perfect!


On the  floor of the table we drilled two 20mm holes to have the possibility to let out water of excess.


....more will follow tomorrow.



Michael

[Graeme]

thanks Michael - very impressive - that's how they managed to get screws in the side...........that is one chunk of aluminium

[ian mcdonald]

My home made (many years ago) and cheaper version (see photo). The staging was made from "handy angle" from a reclamation yard. On the staging I placed corrugated iron. I can,t remember where the wood for the boxes came from but it would have been either cheap or free. I lined the boxes with pond liner. Small holes were made in the pond liner at the bottom to allow excess water to seep through. The boxes were filled about one third with sand. The left hand box was then covered another third of the way up with coir and bark chips. This serves as a site for pleione. The box at the end of the greenhouse was filled another third with a lean mixture of potting compost, consisting of sterilised soil, sand and fine grit. I bought some pieces of flat stone from a well known UK builders supplier (about 50p each). The stone looks like mica schist. These were set on edge to replicate an outcrop, for cushion plants. The box on the right has been left with just the sand in it. This is used to take cuttings and "park" new plants until I decide where to put them. The system is not that good looking but it works. The greenhouse is an ordinary 8x6 with an additional louvered window in the left side, away from the prevailing wind. img. 1010076.

[brianw]

Mine were similar Ian. Pressure treated gravel boards for sides, water proof ply for base. Angle iron fencing posts for legs to the ground bolted internally inside the "box", and then pond liner shaped and pinned to the top edge. Used sink wastes for drainage. The first must be over 30 years old and one has only been used outside of a greenhouse. Made a 6' long once for a friend with 6 legs but mine were each only 4' x 3'.

[Michael Mauser]

Thank you guys for showing a working and resonable way to build a home for alpines. We did it the expensive way it the botanical garden. If I could grow plants at my home (at the moment we raise 3 children, so no place for plants!) I would do it like Brian and Ian.

But now I continue with part 2 of the building of the sandbeds.


To fill in water we put two modified pipes in the corners over the 20mm holes.




There are some gaps covered with fleece and wire-netting to keep the gravel and sand out. But they are big enought to let water in and out.


View from top.



The seams of the box where made tight with silicone before fitting the tubes.



Then we moved the box into the alpine propagation house, two men where enough to do this job.
Before filling it's nessesary to wash everything thoroughly.

[Michael Mauser]

To have good humidity conditons in the sandbed its important that water can move. So at first we put a layer of drainage gravel in (about 5 cm high), there is space in-between the stones to let water flow.




On the gravel we put a fleece to separate the sand.




Filled with sand


Level the sand.

But don't fill the tubes!


Ready for plants


In our propagation we have now 8 sand tables like this, each measures 105 cm x 225 cm x 20 cm. Sounds like a lot of space, but it isn't (there are always plants on the floor...).

The next thread will be about propagation, to keep our collection of Dionysias alive it's indispensible do have enough reserve and to spread plants to others.


Best wishes,

Michael

[Graeme]

I am truly impressed - I would have probibly ended up welding the aluminimum - it is really great to see how different people build things

[Yann]

How much water will you add each time in the tubes? the height of gravel?

[Michael Mauser]

Hi Yann,

sorry for that late reply.
You are right, we add up water a bit highter than the level of the gravel so that the sand can soak water. After a day we open the hole in the bottom of the table to let the surplus water run out. So we don't have permanent "standing water" in the table.

At the moment I'm packing my backpack for a two weeks trip to Iran - I'm very happy about this!


Best wishes,

Michael