[Ebook Việt Hoá] The Instant Guide to Healthy Houseplants: Calceolaria crenatiflora (Slipper flower, Lady’s slipper, Pocketbook plant)

English

The Calceolaria is a native of the cool slopes of the Andes Mountains in South America. It needs similar conditions to survive as a houseplant and is therefore the ideal choice for a shady room or a windowsill out of the sun, where few other plants will thrive. Although it is possible to raise them from seed, they are usually sold already growing in a 6-in (15-cm) pot. Buy them just before the flowers completely open. Flowers should last 2-3 months in cool conditions but may wither in days if kept in dry, heated rooms. Keep the soil moist, but do not mist the leaves or flowers. The soft stems and leaves attract greenfly, particularly when the flower buds first appear. Treat immediately or the  plant may not flower. 

Light 

Protect from direct sunlight at all times but give good light from late autumn to early spring. Keep in shade while flowering. 

Temperature 

Maximum, 50-55°F (10-13°C) for best flowering. Flowers deteriorate rapidly at temperatures over 65°F (18°C). 

Water 

2-3 times per week, water to keep soil moist but not waterlogged. Flowers will collapse if plant gets too dry. Water daily in very hot weather and make sure soilless media does not dry out. 

Feeding 

Feed with diluted liquid house- plant fertilizer every 14 days, using half the manufacturer’s recommended amount. 

Humidity 

Does best in fairly dry, well- ventilated rooms. Do not spray. If dusty, gently dust leaves and flowers with cotton swabs or a small paintbrush. 

Soil 

Use loam-based potting soil or soilless media. 

After flowering 

Plants are generally discarded after flowering is finished. 

Support 

• 1. When in full bloom, the plant is top heavy and may fall to one side. 
• 2. In winter, before flowers appear, insert 4 small sticks around edge of pot. Later growth will hide them, and the plant will be held upright. 

What Goes Wrong 

• Leaves grayish, small buds and flowers: Needs feeding. Give diluted liquid houseplant food every 14 days while plant is in bloom. If in soilless media, feed every 5 days. 
• Leaves pale and soft, leaf stalks tall and straggly: Too dark. Move to a lighter location but protect from direct sunlight. 
• Sooty deposit on foliage: Excreta of whitefly, which will be seen on underside of leaves. Spray with pyrethrum-based insecticide or insecticidal soap according to manufacturer’s recommendations until no more adult flies are seen. 
• Blotchy yellow marks on leaves: Calceolaria yellows, caused by poor light. Occurs when plant is dying back after flowering. 
• Small, round, yellow spots on leaves: Leaf hopper. Spray once with pyrethrum-based insecticide. 
• Plant wilts, leaves have papery edges: Root rot, probably contracted from fungus in soil. No cure. Discard plant to keep fungus from spreading to other plants. Do not reuse soil. 
• Brown marks on flowers: Sun scorch, likely if plant is too dry. Soak pot in water, and avoid drying out in future. May also be caused if flowers are sprayed; avoid doing so. 
• Distorted growing points, especially at flower buds: Greenfly. Spray with pyrethrum-based insecticide. Repeat in 10 days. Weekly preventative spraying recommended, as Calceolaria is very susceptible to greenfly. 
• Flowers turn brown and deteriorate, leaves yellow, plant wilts: Too hot and dry. Keep in a cool, shady spot. Maximum temperature, 65°F (18°C). Plant may be saved by moving to a cooler place. 
• Fluffy gray mold on plant: Botrytis. Possible causes are watering into center of, or heavy condensation settling on, plant. Spray with benomyl twice in I0 days. Prevent by watering carefully into soil and keeping plant in a well-venti- lated room. 
• White powdery film on stems or leaves: Powdery mildew. Spray with fungicide containing zineb. Spray again in I0 days if necessary. 
• Foliage distorted with pale streaks: Viral disease. No cure. Destroy plant, as insects may transmit disease to other plants. Do not reuse the soil.
• Leaves limp, dark and soggy. Soil dark and sour-looking: Waterlogged, due to over-watering or poor drainage. Stop watering until soil is nearly dry and ensure that drainage hole is clear.