It is not possible to deal with frame and cloche gardening proper here. It is a specialised subject to which a whole site can be devoted. However, it should be realised that frames, in particular, can take over much greenhouse work. Many of the low-growing subjects and pot plants frequently given greenhouse space could just as well be grown in frames for much of the time. These include favourites like cinerarias, calceolarias, and the like. Frames can be easily, and economically, heated with electric soil warming cables. Dormant plants can be kept in frames, and much propagation and seed sowing can be done in them. All this gives much more free space in the greenhouse, which could perhaps be put to better use for taller plants. It certainly allows the greenhouse to be used for more decorative plants or the stages during which plants become the most suitable for display. Cloche protection can be given to the more hardy plants before they are perhaps taken into the cold or unheated greenhouse for display. They can also be used for protecting bowls and pots of hardy bulbs.
Frame recommendations are given where appropriate in this site. Frame design and the constructional materials follow much the same lines as greenhouses and similar advantages and disadvantages apply. It is frequently useful to have shady frames, and for this reason the north side of a greenhouse is a convenient place to have frame space. Sometimes the frames can be placed or built in contact with the greenhouse side. This helps to conserve warmth. Sometimes frames can be heated from a greenhouse heating system, more usually when hot water pipes are employed. Generally, however, electric soil-warming cables will be found the most convenient. Suppliers of soil-warming cables will recommend suitable types, ratings, fittings, and air-war1ning cables for frames if given the dimensions and temperatures required. It is also possible to heat a frame with a small paraffin oil heater placed in a sunken pit in the frame. Care is needed with ventilation. Oil heaters of the type used for placing under cars are not suitable since they are likely to give out fumes.
The ground covered by a frame should not be used for growing. It can be treated in a similar manner as suggested for greenhouse floors. It can also be covered with plastic sheeting so that pots can be stood on this out of contact with the soil. Modern lightweight frames are also useful inside the greenhouse for use as propagators, and also for covering plunge beds.