182 ORCHIDS : HOW TO GEOW THEM SUCCESSFULLY. 



D. C. W., SUFFOLK, asks : When the white fleshy roots of Orchids grow 

 over the outside of the pots, what is their proper treatment ? In many cases 

 my pots are quite large enough for the Orchids, but their own roots will climb 

 over, and after a time seem to wither, whereas those that keep on the surface 

 of the pot do not, but keep on growing. I put all mine in pots after reading 

 your remarks at page 39, and so do away to a certain extent with the risk of 

 too great a change of temperature. 



REPLY. Where it is possible the roots should be guided or trained to 

 penetrate the compost, doing so when the young points of the roots are close to 

 the surface. Help is given by making holes in the compost with a small 

 pointed stick, into which the roots enter more freely. When the roots grow over 

 the rim and are a few inches long, they can often be brought on to the surface 

 of the pot and pegged into position. 



QUESTION 2. In potting Cypripediums you say, " pot just above the rim 

 of the pot ; " so many writers say below the rim. Can you give more fully 

 your reasons other than probably the obvious one, that they succeed with you 

 your way? 



REPLY. It is frequently found that when the compost dries quickly the 

 plants do well, but when it remains in a wet and sodden state the plants 

 rarely do so well. Orchids are partial to a good supply of moisture at the 

 roots, but it must pass quickly away. Cypripediums are not so impatient in 

 this respect, yet they generally require a large supply of water, and in such a 

 case the plant derives benefit from being slightly elevated above the rim, in 

 consequence of not being so liable to be over- watered. 



W. A. G-., SOUTH WALES, asks : Could you tell me the reason of the 

 enclosed leaves of Odontoglossum vexillarium turning the colour they have ? 

 The plants have grown well in the Odontoglossum house during the summer ; 

 the leaves came out luxuriantly but all crinkled in ridges, and then turned this 

 brown colour. I have now got the plants in the Intermediate house, and they 

 seem to be doing better. 



RKPLY. The leaves of Miltonia (Odontoglossum) vexillaria are badly 

 marked by yellow Thrip. The irritation caused by these little pests by 

 puncturing the foliage and feeding upon the sap of the plant was effected when 

 the leaves were in a young and tender state, and the brown marks on the 

 foliage is the result. Thrip always attacks the young growth, down the centres 

 of which tobacco powder should be dusted. New growths often come crinkled 

 in ridges, but ultimately become smoother. This crinkling, however, is not 

 natural or desirable, and the leaves are sometimes affected in this way even 

 when grown in an intermediate temperature, yet it occurs more frequently 

 when the temperature is kept too cold or the roots too wet. You did well 

 to remove the plants to an Intermediate house. 



