Miltoniopsis grow in areas in South America where temps don't usually go above 80 degrees during the day and temps around 55-58 degrees at night. Try to keep plants cooler in summer by potting in small clay pots. Keep moint to encourage evaporative cooling at root zone. Ususall 1200-1500 ft candles of light during summer but may be increased during winter months when cooler temps prevail. Best left undisturbed for a few years as they resist repotting. Milts are light sensitive and bloom best in May-June when days are longer and light is brighter. Low concentrations of fertilizer are best as roots seem to be sensitive to salts.
Light should be relatively shaded. Direct sunlight burns the thin leaves within a short period of time. The cool-growing species need approximately 1,200 foot-candles, while the warmer-growing species require closer to 2,000 foot-candles. Hybrid pansy orchids can take and enjoy higher light levels in the 2,000 fc range. is critical for the cool-growing plants. Unless temperatures are kept under 80 F, they may not flower. The minimum temperature is 50 to 55 F. Thus, these are really better thought of as intermediate growers because they need intermediate temperatures throughout the year - not too hot, not too cold.
Water must be plentiful and the medium must drain perfectly. In their native habitat, the plants are drenched almost daily and, because of this, they are intolerant of salt buildup, so leaching every fourth or fifth watering is important when growing in pots. When they are not getting enough water or humidity, the leaves have a tendency to grow with accordion-like pleats. Humidity should be about 50-60 percent because of the plants' need for abundant water. Less humidity will stress the plants and can lead to susceptibility to disease, though too much humidity is worse than too little.
Fertilize at the same level as other orchids: half-strength, balanced fertilizer every two weeks. This can be reduced by half during overcast weather or in winter. A blossom-booster formulation is beneficial in (March-April) when plants approach their flowering period.
Potting should be done after flowering when the new growth is starting. Miltoniopsis should be repotted every other year as they are intolerant of stale conditions. The cool growers (Miltoniopsis) do well in small pots. Any suitable potting medium for fine roots such as 70 percent seedling bark with 15% charcoal and 15% Perlite. For some reason, shallow pans work better than deep pots.
