So far the book has covered “Cultivation in the Open” – now it’s time to go under glass:
Since tomatoes are by no means hardy plants, there are obvious advantages in growing them under glass. Given a little artificial heat, they can readily be grown from seed and furthermore they can be “started” much earlier than plants grown in the open. This in turn means a considerably longer fruiting period and consequently it is possible to obtain a much greater crop of fruit per plant. So much for the credit side. On the debit side there is the undeniable fact that tomatoes grown under glass are subject to more forms of pests and diseases than those grown outdoors. The best protection against these various troubles is careful cultivation and a scrupulously clean greenhouse.
Let me start, therefore, with a note about various types of glasshouse structures.
Glasshouse Structures
A rather forbidding term, but a necessary one ! The tomato is such an accomodating plant that it can be grown successfully in houses of widely differing character and I would hesitate to claim that any particular size or type is the ideal. Much depends upon the size, shape and postion of the garden as well as upon the ideas and resources of the gardener.
Perhaps the commonest type of glasshouse is the span-roof which can be anything from 8 to 20 feet wide, from 8 to 10 feet high, and as long as the garden and owner dictate. Where there is a high wall with a southerly aspect, a lean-to-house may be the best proposition, but the lean-to itself should not be made too wide nor carried too high: 10 feet is ample. With this type of house, the glass should be carried down as near to the ground as possible so that prepared beds can be made on the “floor” of the house. As we shall see later, ventilation is a most important factor in tomato cultivation and thus, if a new house of any type is being erected, remember to ensure that there are ventilators as low as possible at the sides as well as in the top of the roof.
There is no need to despair if neither a span-roof nor a lean-to is avaliable or practical in your garden. A glass-covered porch or veranda has been known to produce a good crop, while today there are several small sectional structures avaliable which, although really only giant cloches, are in effect small unheated glasshouses capable of carrying very fair crops of tomatoes.
This mention of heat introduces another point. Tomatoes can be grown very successfully in unheated structures but such crops are, of course, later than those brought on in a regulated temperature. Small built-in coke boilers with water-pipes of 3 or 4 inches diameter are probably the most economical and reliable for the amateur. Electric heaters are more expensive but have the advantage that they can be thermostatically controlled, while a third alternative is the modern type of small oil-burner, which is inexpensive both to buy and run.
Finally, as I have mentioned earlier, outside crops can be brought on much earlier if they are given the protection of cloches.
What I’ve especially enjoyed about working my way through this book from the ’50s is noting what feels different and what feels the same. This passage does mark a passing of time. Yesterday’s interview with Neil highlighted the decisions gardeners now take regarding the cost v value of heating a glasshouse. I’m sure given the modern day context of affluence and technology compared to nearly 60 years ago – it would be a surprise to the gardener of yesteryear to learn that a heated greenhouse is now a luxury which the humble home grown tomato – no matter how delicious – can’t justify !
And that the greenhouse is now seen as protection against the main enemy of the tomato – blight. Whereas Mr. Cuthbert’s view on tomatoes was clearly very similar to the 50s view on babies – which is outside in the fresh air – the more, the bonnier !
