Paph Loosing Leaves
 

This is my first paph so I am nervous about it. It is a cross of Lorraines Pride and Sibling, the mottled leaf type.

I have had it for about three months. It initially had three leaves. I keep it inside hear a frosted window facing NE. Water is RO or RO with fertilizer. As per the grower, I let it sit in about 1/4 inch of water.

It has been doing great, going from three to six leaves. It budded about a month ago and was doing very well. The bud is bout three inches high at this time and may bloom in a few weeks.

The worry is that three leaves have yellowed and will fall off soon. I don't know if this is natural in a blooming paph but it is alarming.

Any comments?

Cheers.

Are the leaves yellowing from the bottom up, or are upper leaves yellowing?

What is the potting medium? I keep my Paphs moist but do not stand them in water. However, that probably works with large chunks of medium.

Paphs and Phals are fine with most tap water. I don't use collected rain nor RO on them, saving it for other orchids.

A photo would help. Paphs do shed the leaves of old growths as the new ones develop. But without a photo, can't tell if that the situation or something else is going on. Personally, I would not let a Paph sit in water. (Phrags, yes... but while Paphs need to stay damp, don't want to be soggy). What are your temperatures? What is the medium?

Attached is a snapshot. The potting medium is unknown, it was purchased earlier this year from a local professional grower.

Temperature is indoor 73-65F. Water is RO with Orchid Pro 7-8-6 1/4t.gallon every third watering.

The sitting in 1/4 inch of water was per the recommendation of the grower. Subsequent research has indicated this may be too much. In defense of her advice the thing was thriving, doubling in size over the course of months.

Cheers.

Where do you live? TEmperature, humidity can make a difference in "how much water". The top of the medium looks pretty coarse, so the bit of water to sit in may be correct for the combination. I pot Paphs in small bark, which is water-retentive, so then sitting in water would not be so great.

The leaf-yellowing looks normal to me - once that growth blooms, the rest of the leaves will eventually yellow and drop, but by that time you should see a new growth emerging. Paphs only bloom from a given growth once, so once that has been accomplished, the energy goes to new growth.

One thing to keep in mind... after this bloom, it could be 2 or 3 years before you see another. Also normal. Paphs tend to do a new growth as they bloom on the old, then put down roots (which can take another year) and then bloom once both the growth and roots are mature (likely another year) Once this bloom is done, you should repot - because they stay on the wet side, the medium for Paphs tends to break down pretty fast (like a year or two) so they need more frequent repotting than a Catt or Phal in medium that dries out more between waterings.

The top of the medium is small rock. Unsure about the rest as I would have to depot it.

The location is Southern California, Camarillo. It's inside with day/night 73/66F right now.

Interesting information. So the first growth will die off completely? But not before a new growth starts?

Are paphs monopodial or sympodial?

Thanks for the answers.

I've had great success with other orchids but this is my first paph. I doubt that they are my future, but tending to this one has been interesting.

Cheers.

Once it has done its blooming (no rush...) you'll be unpotting it at any rate. I'm sure that it could use that...

A note here... Paph roots look completely different than those of other orchids. Brown and fuzzy is a good root! So when you repot, don't go cutting roots, and handle with care, they tend to be brittle and you don't want good roots breaking off in your hand. Just rinse off gently under the faucet and add new medium.

Right, the old growth will die off but hopefully the new one will be well on its way before that - the new growth will be using the root system of the old one for a year or so until it develops its own.

Indoors is fine... this type of Paph (Maudiae type) grows under Phalaenopsis conditions, warm and shady. There are other Paphs that would do fine outside (even in winter) where you live (like the "bulldog" types, or anything with dominant Paph insigne or villosum)

Paphs are sympodial - new growths appear along a rhizome/stolon rather than from a central growth point. When happy, they can put out multiple new growths, forming a clump. Once there are multiple growths, with several at different stages, it blooms more frequently. But it's a pretty slow process.

Roberta,

Thanks so much. I was planning to repot after the bloom and it will be interesting to see the roots. If you have any ideas for a good medium for indoor use please advise. Ideally it would allow watering on a weekly basis, perhaps more in winter when heating lowers humidity.

By the way, I have spent some productive time at your website, thanks for the work at putting it up.

Cheers.

Thanks! Glad you enjoyed!

For Paphs, I use the small ("Classic") Orchiata bark. Rexius works OK too. (but if you use that, wear gloves, it has splinters) In a pinch, you can use plain old seedling bark of the sort that is used for Cymbidiums, but it will break down faster. Once a week is likely not enough - better to have good drainage and water more often. Others on the Board use the semi-hydroponic approach with good results. I can't advise there since I don't use it.

Paphs are monocarpic like Agave. They produce new offsets either before or after flowering. The growth that flowered will eventually die after flowering.

You're providing next to no fertilizer, and it will harm the plant long term. Read some in the Paph forum here about fertilizing. The flower on your plant may have formed before you bought it.

I agree with ES's remark about the fertilizer. For Paphs and many orchids it's good to aim for roughly 75-100ppm Nitrogen per week. The dosage you are giving now is only 20ppm per watering, so you'd have to water 4-5 times a week with fertilizer to be in that ballpark!

I looked up that fertilizer, and see that the recommended dosage is 1/2 tsp per gallon. Is there a specific reason that you reduced it?

The loss of lower leaves by what appears to be an otherwise healthy plant is a good indicator of insufficient nutrition; the plant is moving previously-absorbed nutrients from existing tissue into newly-growing tissue.

If properly grown, old growths can hang around for years after blooming, adding to the resource accumulation and storage for the colony.

I'll increase the fertilizer as per the previous posts. It does look like I was under-fertilizing. The very dilute fertilizer works so well on my phals that I used it with the paph.

It actually seems amazing that the plant was doing so well.
As far as the bloom spike, I watched three new leaves grow up over several months. I then noticed something coming out that did not look like a leaf and it turned out to be a bud.

So there was no bud when I bought the plant.

Thanks for all the help.

The buds of many monocarpic plants form a year or more before they can be seen. This includes Agave, Paphiopedilum, and biennial Allium (onion, garlic.) They remain microscopically tiny deep inside the rosette, with tiny leaves surrounding them that have not expanded yet.

When you plant a clove of garlic, or a small set onion, the flower may already have initiated.

Each fan of a Paph will grow for a while, then the terminal meristem forms an invisible bud deep inside the fan. That growth will not grow more new leaves, but already-formed tiny leaves near the meristem will continue to expand. The fan may produce more growths from the base, from meristems that didn't develop.

I suggested the bud on your Paph may have formed before you bought it, but remained microscopically small at the center of the rosette. The plant was coasting on the nutrients stored in the plant while at the nursery. As it expanded the bud, it ran out of stored nutrients. As Ray said, it is likely cannibalizing old leaves to sustain the flower.

estación seca,

Wow. Thanks for the detail.

Cheers.