The Garden Under Glass

40 THE GARDEN UNDER GLASS and sharp sand to further ensure porosity. This should be thoroughly mixed, and used when moist so that it will hang somewhat. The plants should be potted up as soon as they are received from the nursery in clean, well-drained pots which will comfortably contain them, and the soil will need to be well firmed. Careful watering is essential, for if the centre of the ball of earth becomes dry nothing short of Immersion for several hours in a pail of water will remedy the evil. Subsequent potting is best done about a month after the plants have flowered. At each potting the ball should be reduced in size to make room for fresh compost. Flower heads that are faded and seed pod should be removed, and until growth is completed detention in a warm house, with daily syringing, is advised. Later, after due hardening, they may be stood outside for a couple of months though not in full sunshine. If it is intended to force azaleas they should be brought into heat gradually. Hard forcing is not advised. Good varieties are Deutsche Perle, Vervæneana, Empress of India, Reine des Fleurs, Baronne de Vriere and Sigismund Rucker. The great enemy is thrip (see Greenhouse Pests). Begonias, Tuberous and Fibrous-rooted Without the begonia our greenhouse would not be so bright either in summer or winter. Some regard it as a difficult subject because they have not managed to get their seeds to germinate, or have fonnd the bulbs rotten after drying off. These difficulties are easily surmounted. Let us deal firstly with the tuberous section. There are doubles and singles of all shades and they can be grown from seeds, from tubers, or from cuttings.