Paph with affliction

[marjie]

Hi there! I'm pretty new to orchids - I just have two which I've been caring for without incident for a couple months.

Today I noticed the tip of one of my paphiopedulum's leaves was turning brown and had nasty looking black spots on the underside. Anybody know what this is?

Earlier in the season I had spider mites on a different house plant in a different room, which I treated successfully by spraying it with watered down dish soap regularly, so I went ahead and did that to this guy this morning just in case.

[estación seca]

Welcome to the Orchid Board!

What are your temperatures, day/night? Humidity? What kind of light does it get? How are you watering it? Are you fertilizing it? Do you know the name of the plant?

Spider mites rarely affect just part of one leaf.

[marjie]

Hey thanks for your response!

I keep the room around 68-70f. Humidity around 50-60%. Natural light in an East facing window though it is often cloudy here. I'm watering with tap water once a week, and lightly fertilizing every other week. I got it from orchids by hausermann, it was listed as Paphiopedilum Olympic Moon.

[estación seca]

It's what is called a complex Paph hybrid, or sometimes a bulldog hybrid, because the flowers are wide and full. They tend to be fairly easy to grow.

What you are seeing can be caused by not getting enough water, or by too much salt and mineral content in the medium. Not getting enough water can be caused by not watering often enough, or by sick roots. Paphs need very little fertilizer, much less than most other orchids. It is possible you're overfertilizing.

Unlike some other kinds of orchids, Paphs should never dry out completely. Try to water frequently enough that the medium never dries out. When you water, thoroughly soak the medium and let water run out the pot. Most people need to water them more than once a week.

What do you mean by "lightly fertilizing?"

If your medium is not drying out with your weekly watering, the roots might not be in good shape. I suggest gently slipping it out of the pot to check the roots. Paph roots look different from other orchid roots. They should be a rich brown to red-brown, and fuzzy.

It may have been in that pot for some time, and it may have old medium. When you slip it out of the pot you can see whether the medium is still fresh, or starting to rot and crumble. If it's crumbling and powdering, you can repot the plant with new medium. You could use fresh medium bark and the same pot, unless there are so many roots they are jammed in the pot. Paphs are generally repotted every year or two in the spring, but they rarely mind being repotted in off seasons if the medium is old and decomposing.

[Tango]

Hi,
There is not really anything to add to Estación Seca's response. Paphs are very slow plants and take months to stablish and start growing. I would only fertilize if they ask for it (if they show some new growth).
Hope your plant recovers.

[marjie]

Thank you so much! I'm really surprised cause everyone told me with orchids don't over water them ha ha.

I suspect it's the water and not the roots. I pulled the plant out of the pot and examined the roots and medium when I got it a couple months ago. Granted I don't have a great idea of what I'm looking for, but I saw lots of thick fuzzy brown roots snaking around not looking rotted.

Also recently some roots have grown out the bottom of the inner pot, and she's showing signs of growing another leaf. Which is why I started fertilizing recently. I was trying to do half the recommended dose, which is what I heard orchids like, but I wasn't measuring it very precisely so it's possible I put in too much.

[Tango]

Your plant will for sure recover. It's in good hands.
Be careful with the rule of 1/2 fertilizer dosis, many manufacturers tend to recommend very heavy fertilizing schedules... Which may be okay for lettuces but definitely not for orchids! Even diluted! Always look at the numbers in the label and compare to those on an orchid fertilizer bottle.
Orchids are extremely efficient at capturing nutrients from water, so no need to provide much fertilizer.

[estación seca]

Orchids are extremely variable. Paphs don't grow anything like Cattleyas. Go to firstrays.com and read about fertilizer, especially how to calculate doses. Paphs need far less than other orchids.

The orchid curator of the Huntington Gardens spoke to our society about slipper orchids. He talked about fertilizer. You can find my lecture notes if you use Advanced Search in the upper maroon menu. Put in search terms DVOS and Brandon.

[Paphluvr]

It looks like you have a plastic pot inside of a decorative ceramic pot. Do you take it out of the decorative pot to water it? If not, you could be getting a buildup of minerals or salts in the medium. Also, the plant can't dry out (breath) as quickly as if it were just a plastic pot sitting on a plastic saucer.

[Tango]

It's an impressive amount of information. Thanks for sharing!