If you’ve noticed small spots on your orchid blossoms that aren’t natural parts of the petals, you may have a problem with Botrytis cinerea. Also called gray mold or just botrytis, this disease is common among Phalaenopsis and Cattleyas flowers and can sometimes affect other varieties too. Here’s what you need to know to protect your houseplants from infection.

What Is Botrytis?

Botrytis is a fungal infection that develops when mold spores land on an orchid and start to grow. They cause small, dead brown spots that are sometimes surrounded by a ring of pink. The infection can get worse, making the spots larger; in severe cases, the spots may develop into an interconnected web.  However, this fungus is not systemic where it's harming your plant.  Not to worry, it's only affecting the current blooms.

What Causes It?

Botrytis spores are present in the environment but aren’t always able to grow directly on your plant. You’re more likely to see spots on flowers when there is a high concentration of spores, which can happen when dead flowers and leaves are left in or near a flowerpot or when other plants nearby are infected. 

Moisture also plays a critical role. Botrytis and other fungal infections need lots of water to develop, which can happen when your plant’s growing medium has poor drainage or the environment has high humidity.

How Can You Prevent It?

First, gently remove the flowers from affected plants.  Once the effects of botrytis appear on the flowers, it can't be reversed. Also, remove any dead plant parts that may be harboring mold. 

Spread your orchids out to allow for air circulation between them, make sure the area is well-ventilated, and lower the humidity. When you water the plants, water the base of the stem, not the flowers or leaves, as moisture sitting on the plant makes it easy for fungus to grow. Time your watering early enough in the morning so the medium can dry out by the end of the day and won't sit wet overnight.

For beautiful orchids to decorate your home in Hawaii or on the mainland, turn to Akatsuka Orchid Gardens. Based in Volcano, HI, this family-owned nursery provides a wide selection of tropical plants, including unique orchid hybrids found nowhere else. They guarantee your plant will arrive healthy and offer tips to help you keep it that way. Call (808) 967-8234 with any questions, or check out their selection online.