194 GARDENING FOR BEGINNERS 



Phaius, The P. grandifolius section and the hybrids that have 

 been derived from the intercrossing of the various varieties, may be 

 placed in the intermediate-house. They like a close, humid atmos- 

 phere while in active growth, and when the growths have matured they 

 remain dormant for several months, during which period only sufficient 

 water will be required to keep the plants plump. A compost of good 

 fibrous peat, a little loam, and a liberal sprinkling of rough sand meets 

 their requirements, and the drainage must be clean and ample. 



Sophronitis grandiflora. This is the most charming of the 

 miniature cool-house Orchids. The deep orange-scarlet flowers are pro- 

 duced in the depth of winter and through the early spring, when they 

 make a brilliant display, lasting for some weeks. This Sophronitis is 

 suitable for growing in pans, which may be suspended near the roof 

 glass. The potting requirements are the same as for the Mexican 

 Lselias. 



Vanda. The bulk of the Van das, although closely allied to in- 

 termediate-house Orchids, require a warm, close atmosphere during the 

 growing season. There are a few exceptions, and one of the best of 

 these is the azure-blue flowered V. caerulea. This species may be grown 

 in the cool-house or in a vinery, the shade from the vines in the latter 

 structure being sufficient protection from the sun. An ample supply of 

 moisture during the active season of growth is required, and a dry and 

 cool condition during the resting season. Grow the plants in baskets 

 suspended from the roof, where with the vines they may be freely 

 syringed. The potting compost should be renewed each year, and 

 consist wholly of broken crocks and living sphagnum moss. 



Zygopetahim. Such species as Z. crinitum and Z. Mackayi are 

 easily procured, and should be grown in the intermediate-house. The 

 potting compost of loam, fibrous peat, and sphagnum should be pressed 

 moderately firm about the roots. The plants should not be disturbed 

 more than is absolutely necessary. 



Insect Pests. Many insect pests infest Orchids, but the pests to 

 be most dreaded are thrips. These get into the central and most tender 

 portions of the plants and if not detected cause much mischief and 

 anxiety. Small as they are they soon cause a damping spot such as 

 would be made at first through pricking with a pin. This soon changes 

 colour and results in a brown burnt-up appearance and permanent dis- 

 figurement. These are what are termed by gardeners the yellow thrips. 

 Black thrips are larger and are more easily destroyed. The eggs of the 

 latter are deposited on the under sides of the leaves, and may be removed 

 with a soft sponge. The best preventive is to fumigate with XL- All 

 Vaporiser about once a fortnight, and to spray with the liquid pre- 

 pared for the purpose by the same firm of manufacturers ; but only spray 

 in warm, bright weather, and when the outside conditions are favourable. 

 Scale is destroyed by carefully cleaning with a brush and sponging with 

 weak soft soap water. Cockroaches are most destructive to the young 

 roots and tender flowers. These may be trapped by placing jars of 

 treacle and water about the stages, or phosphorus paste " chases." Wood- 

 lice are also destructive to the young roots, and may be captured by 



