INFORMATION AND CULTURAL NOTES IN THE 
GROWING OF ORCHID PLANTS 
TEMPERATURE — The word “Intermediate” following a heading of the plant lists, 
means that these plants do best in a house whose minimum temperature is 55 degrees 
to 65 degrees at night. A night heat of 55 degrees as minimum on extreme cold nights 
and 60 degrees in moderate weather will be better for the plants than a higher temper- 
ature, especially if they are in bloom. In the day a 60 to 75 degree temperature is good 
and in the summer as low as outside conditions will permit. ‘Cool’ means a minimum 
temperature of 40 to 55 degrees. We have indicated below the type of house each 
variety prefers but we have seen amateur growers successfully growing plants of mix- 
ed varieties in one house merely by utilizing the various parts of the house for the 
individual plants that need the cooler or warmer end. This is soon discovered by the 
observant grower. 
AIR—Air must be given at all times when possible. The house must have free air, 
day and night, from May to September and at all other times when the weather per- 
mits. The air of the greenhouse must never be permitted to get stale or musty. 
Oftentimes a small crack of air will prevent this. The more air used, the more water 
will be required to maintain humidity. 
WATER—Orchids want a fairly moist atmosphere, which means a humidity of 70 
degrees or more. This can be maintained by watering between the pots and damping 
the walks and under the benches once or twice a day. There are many devices now 
sold to record the humidity of the greenhouse. In winter, water is best given to 
the plants in the morning so that the surplus will dry off before night. It is im- 
possible to lay down certain rules for watering as the general conditions surrounding 
the plants in their native homes vary greatly. As a rule, most orchids plants need a 
liberal supply of water. Newly potted plants should be watered sparingly for several 
weeks until the new roots are established. On cold cloudy days when temperatures 
are low, very little water is needed. In the summer when the air is very drying a 
light spraying overhead two or three times a day is needed. Cattleyas especially love 
the light overhead syringing several times a day on bright sunny days. All plants 
must be so placed as to allow all surplus water to drain off. 
SHADING—From early February to late October shading must be provided. Outside 
roller blinds are far superior to any other method as they can be left up on cloudy 
days and raised in the afternoon when the sun is low. Satisfactory results can also 
be obtained by shading with white lead and gasoline, which should be applied lightly, 
just enough to exclude the direct rays of the sun. In a house having full exposure 
to the sun in the winter, orchids will need shading to some extent. Cheesecloth stretch- 
ed a few inches from the glass will provide heavier degrees of shading for those species 
which require it, such as Cyripediums. 
POTTING—Species bloom at stated seasons, but the hybrids are of irregular habit, due 
perhaps to their mixed origin, they blossom and need repotting throughout the year. 
This makes it difficult to make a rule as for the potting but the best time to repot 
hybrids is after they have bloomed. A plant is generally repotted every two or three 
years. Many plants should not have their root action disturbed and should not be 
repotted every year. Three general rules are (1) when the compost decays (2) when 
the plant does not thrive due to faulty drainage (3) or when they have outgrown their 
pots. 
