Once you have started a hydroponic home garden and become accustomed to the case and simplicity of soilless plant growing using the simple method described in this book, you may well feel —if you have the space—that you would like to extend your unit. In the case of indoor pots and troughs this may be just a matter of multiplying the number of containers. However, where circumstances permit, other possibilities exist. For example, one can frequently lay out a small roof garden or use balconies and backyards or the edges of paths for interesting and profitable displays of hydroponics. Even in winter, it is quite simple to use polythene sheeting to erect cheap covers, plant houses, cloches, and similar shelters for tender plants outside the house. Glass-enclosed verandas protecting front doors or french windows also provide scope for tiers of attractively arranged containers. Of course, at cold times, it is necessary to fix up some form of heating, cither by connection to the house installation or from electric heaters and paraffin stoves. Finally for those with a greenhouse or conservatory already available, conversion to hydroponics has numerous advantages. In hot regions, the merits of garden plant houses which afford shade and cooling sites arc well known.