 |
|
|
Growing plants in a trough is one of the most satisfying ways of viewing one's treasured alpines. MAKING THE TROUGH Firstly, obtain your polystyrene box. Consider even the smallest of them as there is usually space to be found for a small trough. Consider too, that they can be readily modified by glueing two, three or even four of them together. The possibilities are endless. Next, make suitable drainage holes in the base of the box with a sharp knife or some such implement. I would normally make the holes around 25mm diam. and place them at 13cm intervals. The
basic ingredients for the hypertufa mix are readily
available from garden centres, nurseries or builders
supplies. They are Fine grade Portland Cement Gritty Concreting Sand Dark, Finely Sieved Peat
There are numerous blends one can use but I am convinced, having made over 30 of these troughs, that the best is:- 2 parts Sharp Sand 2 parts Peat 1 part Cement
The mixing is the most difficult aspect of the work to put into words but basically it is necessary to mix the ingredients dry so that a perfectly homogenous mixture is obtained. This is also why it is vital to use sieved peat. If any lumps are left in, they will not break down during mixing and will be seen all over the surface of the finished trough. In addition to being unsightly, these lumps will eventually decompose and fall out, leaving holes for frost to invade. You have been warned.
When a uniform mix has been achieved, begin to add water slowly, whilst stirring continuously. The mix needs to be "the wet side of moist." (To expand on this highly technical terminology, when a fistful of the wet mixture is squeezed, it should retain its shape without either oozing water, or falling apart. A bit like dumplings, if you will). When mixed correctly, it will remain workable for about thirty minutes. An adhesive is required to give the hypertufa a key to the polystyrene surface. There are many adhesives on the market but only two types are suitable. They are
PVA (Polyvinylacetate) and EVA (Ethylvinylacetate)
These are readily available in the form of white woodworking adhesives such as Unibond and Evostik amongst others.
When mixing and applying the hypertufa mixture, it is important to wear protective clothing, i.e. kitchen gloves (Marigold or similar). The wet mixture will ruin your skin, fingernails etc. and the lime content in the cement can be an irritant.
Firstly, stand the box upside-down. Coat the bottom of the box and one quarter of its sides with the adhesive and then immediately apply the hypertufa to the coated area.This is contrary to the manufacturers recommendations but if you follow my instructions, a complete bond will take place between the three components. Apply the hypertufa by hand, moulding it like modelling plasticine. This will give the end product a 'natural stone' look. Pay particular attention to edges and corners. These usually need an extra thickness applied to prevent damage. I would consider a thickness of 15mm to be adequate, so 20mm on the edges and corners should suffice. The overall effect should look like stone that has been hewn out of rock. Allow this to dry overnight.
Next, turn the box the right way up, coat the rest of the sides, the top edges and at least 5cm down the inside of the box with adhesive and again, immediately apply the hypertufa. Do not worry about getting adhesive onto the previously treated parts, a brushing of the hypertufa over that area will soon cover up any excess adhesive. Leave the whole to dry for a minimum of 24 hours before planting - longer if you have the patience (but then what gardener does?) TIPS Only make sufficient wet mix for one session. Don't be tempted to try to cover the whole box in one session. IT DOES NOT WORK Be safe: Use protective clothing where necessary.
Advantages: 1. The cost of obtaining the boxes is negligible 2. You can fill the car without carrying too much weight. 3. When finished, the troughs are a fraction of the weight of the real thing. 4.... and please, no offence intended here, but these troughs are ideal for ladies and the elderly, as they are lightweight and can be moved from place to place without too much effort, Because of their portability, it is possible to plant them with frost-tender plants which can be stood outside during fair weather and taken in during foul. 5. The polystyrene core gives these troughs an excellent insulation property. This provides the roots with a much more stable temperature than is experienced in natural stone troughs, a benefit in both summer and winter. 6. They make great gifts and raffle prizes at your local groups and chapters - (Ask Phyllis Gustafson of Oregon). Disadvantages The only real disadvantage, is that it takes a couple of seasons for the troughs to look "weathered".
|
|
