Home › Flower Cultivation › Article

What causes white granules and mold on Phalaenopsis roots, and how do you deal with it?

Flower Cultivation By Grace Miller 0 views
Have you ever noticed dense white spots sprouting from the roots when growing Phalaenopsis? Don't panic, this could be southern blight or Leucocoprinus birnbaumii fungus. Today we'll teach you step by step how to tell them apart and give first aid. 1. Identifying southern blight. Southern blight is an extremely stubborn fungal disease! In the early stage, white thread-like growth appears on the roots, as if wrapped in a layer of

Have you ever noticed dense clusters of white specks appearing around the roots when you grow Phalaenopsis orchids (moth orchids)? Don't panic - this could be southern blight or the fungus Leucocoprinus birnbaumii. Today we'll teach you step by step how to tell them apart and give first aid.

I. Identification

Southern Blight

Southern blight is an extremely stubborn fungal disease! In the early stages, white thread-like growth appears on the roots, as if they were wrapped in a layer of white cotton fluff. In severe cases, the root system dries out, becomes hollow and rots, and eventually the whole plant wilts and dies!This pathogen reproduces extremely fast. Once infected, if not treated promptly, the Phalaenopsis orchid will most likely"face more danger than safety"!

Leucocoprinus birnbaumii

Those of you who often grow Phalaenopsis orchids in bark have probably seen this little white mushroom! Although Leucocoprinus birnbaumii has a scary name and contains the word"toxic"

II. First Aid

First Aid for Southern Blight

Emergency repotting: as soon as you notice an infection, take the Phalaenopsis orchid out of its pot, gently loosen the roots, and clean off the old potting medium, such as bark and sphagnum moss, to avoid secondary infection from residual pathogens.

Sterilising soak: prepare25% carboxin wettable powder and dilute it into a1000-fold aqueous solution, and soak the Phalaenopsis roots completely in the solution for30minutes to eliminate the pathogen thoroughly.

Dry thoroughly: do not pot it straight up after soaking! Put the Phalaenopsis orchid in a cool, ventilated place to dry for1-2hours, letting the moisture on the root surface evaporate naturally to prevent dampness from triggering a second round of disease.

Repot in fresh medium: use brand-new potting medium such as sphagnum moss and bark, together with a clean pot, to replant it. It is recommended to mix a small amount of carbendazim powder into the potting medium to boost the preventive effect.

How to Deal with Leucocoprinus birnbaumii

Bottom-watering with carbendazim: put the pot into a carbendazim solution diluted1000-fold and soak it for30minutes to kill the mycelium in the soil. Afterwards, remember to put the pot in a ventilated place to dry thoroughly.

Increase light: this little mushroom is afraid of light! Move the Phalaenopsis orchid to a windowside spot with indirect light and make sure it gets2-3hours of light a day, avoiding harsh direct sun, to suppress fungal growth.

Improve ventilation: open the windows regularly for fresh air, or use a small fan on low speed to blow a little air, reducing the humidity around the pot.

III.Daily Prevention

1.Scald new potting medium with boiling water or sun it for3days to kill potential pathogens.

2.Phalaenopsis orchids are epiphytic plants and are afraid of waterlogging! Water only after the sphagnum moss has dried out completely, and promptly pour off any standing water in the saucer after each thorough watering.

3.Every week, pull the potting medium aside a little to check the roots, so problems are spotted and treated early.


Related Articles