Equipping Your Greenhouse
Buying theand putting it up is not, unfortunately, the only expense with which you will be faced. You can certainly start the ball rolling without any added equipment and gadgets but you will soon want to expand your interests.
For instance, you may well find that staging is not included in the basic price.
This is where you might start reaping the benefit if you have bought a wooden greenhouse because it really is quite easy to make and install your own staging if you wish to.
For most purposes, it is a good idea to have staging on just one side of the house; preferably the south or west. This is so that the smaller plants on the staging will not then have shadows cast on them by the taller ones standing on the ground along the other side.
On the staging will obviously go all the seedlings etc. that you will be raising in the normal course of. However, it can also be used for in pots or other containers that are in the greenhouse during the early part of the year for forcing.
The ground on the opposite side of the house will be used for standing pot grown trees on. In some cases where a larger than usual greenhouse is being used, this border on the other side of the greenhouse may be planted with, or , or possibly a . Normally, however; the tree fruits mentioned are against the back wall of a lean-to house where they take up very little room but revel in the sunshine and warmth.
Depending on the kinds of fruit you are growing, or intend to grow, you may find that temporary staging is more convenient than a fixed set-up. If this is the case, one of the most convenient materials is corrugated asbestos, or its modern equivalent. This can be placed on legs to raise it to the desired height and then covered with gravel or lightweight aggregate for a level surface. If the sheet is large, drill someholes in the troughs.
You may also find it handy to have shelves as well as staging in the greenhouse and, here again, this is often where a wooden house scores over a metal one.
Shelves can go on either or both sides of the house, depending on how much you need, but never make them too wide or they will need special strengthening to make them safe and sound; 6-8in (I 5-20cm) is about right. They can be usefully employed for holding seed-trays and pots up to about the 5in (13cm) size. The whole object of the exercise is to make the most economical use of the greenhouse and its heat but, at the same time, to grow what you most want; in this case, a fair amount of fruit.
Some thought will also have to be given to the floor covering, both under the staging and over the rest. The normal routine is to leave it as bare earth under the staging; this allows drainage water from above to soak away and you’d be surprised at just how many shade-loving plants you can grow in pots under there.
Ashould be made down the middle of the house and, here, you can use a number of materials. Remembering that this area is going to take a lot of use, it should be covered with something durable like paving stones, concrete or bricks. It is really a question of which is going to be the cheapest and easiest to come by.
If a large number of trees in pots or other containers are envisaged, it might pay to continue the hard-standing right up to the other side but, usually, the pots are stood either on the bare earth or on slates or tiles.
However, something is required under the pots or you will very soon find thatwork their way into the compost and create serious difficulties with the watering and the structure of the compost in the pots. As a temporary measure for use at certain times of the year, slatted duck-boarding can be put down for the pots to stand on.
From the fruit’s angle, insulation from the cold will not be needed; most of the plants that we will be growing in the greenhouse are perfectly hardy. However, if you want to keep a reasonable winter temperature in the house during the winter for other occupants, bubble plastic is a godsend. For the fuel that it saves, it costs very little and has the advantages over a single sheet of polythene of giving better insulation against the cold and also of being much less likely to encourage the formation of condensation. That has always been the curse of single-thickness polythene sheeting.
The opposite requirement to insulation is shading and this is going to be needed in the summer to stop the temperature rising dangerously high.
Whitewash has long been the traditional material for shading. Painted on the outside of the glass, it keeps a lot of the sun’s rays out without creating gloomy conditions inside. There are more sophisticated equivalents now though, possibly the best being one that almost disappears when the sun is in, but which intensifies when the light strengthens.
Although these are perfectly satisfactory, the netting kind of shading is better, provided that you rig up a system for raising and lowering it as the conditions dictate.
The Rolls Royce treatment, though, is a set of roller blinds that are pulled up and let down as required. Needless to say, this is also the most expensive system.
On the same subject of keeping the plants cool, it is well worth fitting an automatic opener to at least one of the roof vents. This ensures that some cool air is getting into the house even when there is no one there to look after it.
As heating is not the main requisite of fruit under glass, it will be sufficient to say here that the most you will normally be called upon to provide is sufficient to keep the frost out once growth has started in the spring. Always remember, however, that spring starts a good deal earlier under glass than in the open. With this in mind, a paraffin heater is usually ample. However, it must be a good one so that fumes and smoke are not given off; these will seriously damage young growth and blossom, as and when they appear. The blue-burner type is normally the most satisfactory. A step up in efficiency, and less likely to give any problems, is the propane-burning type.
As far as watering the plants is concerned, it must always be remembered that you can never rely on enough water falling as rain. This is an obvious comment for plants in the greenhouse, but it applies equally well to those in pots which are standing out in the open.
There are several aids to watering, such as drip-irrigation kits and capillary matting, but most gardeners will rely on their own judgement.
Grapes and peaches planted in the border soil will normally have enough water at the roots once they have been established for a few years; they are roughly the same as trees planted in the open. However, during periods of water stress in the summer, it could well be necessary to provide them with extra. This is particularly important when the fruit is setting and then swelling.
Most trees growing in pots will be outside during the summer and will need attention every day; if they run short of water during the growing season and when they are carrying fruit, they can well suffer.
How often they will need watering is anyone’s guess; it depends on the weather, the amount of root in the pots, the size of the plants and how much the natural rainfall supplies. To give a rough guide, though, they should be looked at every day during the growing season in case they need watering. When the surface of the compost dries out, it will be safe to water because, provided that the drainage is as good as it should be, any surplus will run through. Having already moved slightly into the cultivation side of greenhouse fruit growing, it would be as well not to proceed further without looking at the subject in a much more general way so that, in effect, we start at the beginning.
The idea ofin a greenhouse probably conjures up a picture of Georgian orangeries. Not a bit of it; you can perfectly well use the old 8 x 6ft greenhouse that you’ve been keeping in. The only difference is the scale of the operation.