Occasionally Phalaenopsis orchids may fall foul of a type of rot. There are many different types that can affect orchids, but this time, we appear to be dealing with stem rot. At the base of this Phalaenopsis orchid there is a small patch of black tissue, which appeared after the bottom three leaves turned yellow and fell off. One leaf at a time is normal – but three? No.
Stem rot is caused by water accumulation on the stem of a monopodial orchid. The plant tissue begins to decompose and turn black, and if left untreated, can cause the orchid to perish. It is usually preventable, but commonly happens when our plants get water in-between their leaves. A simple way to prevent it would be to remove the excess water, or try to avoid splashing onto the orchid itself in the first place.
I decided to do an emergency un-potting to be able to get at the dead tissue easily. Unfortunately, it looks like the stem rot has affected more of the stem tissue than I first thought. I am attempting to treat this with hydrogen peroxide 3% and cinnamon. The hydrogen peroxide 3% should kill off the rot, whilst the cinnamon helps to dry out the affected area, preventing it from spreading to the rest of the plant.
She will require a re-pot and will be placed higher up in the plastic pot to help reduce the risk of this happening again. I have noticed how small her root system is compared to other orchids in my collection, but she is still young.
I’ll keep you up to date on whether this treatment works – hopefully this rot has been dealt with in time to save the orchid.