Advice needed from other Paph. sanderianum hybrid growers

[Laura81]

I have had a Paph Oberhausen's Diament crossed back into Paph sanderianum for about 4 years. It's potted in a 2 inch clear plastic aircone pot with a mixture of small coconut husk bark, hydroton, coir, sponge rock, and a top dressing of crushed oyster shell. I flush it thoroughly twice a week with tap water, followed by DI water and I fertilize lightly once a week. It's currently outside for the summer and gets morning sun. I also mist the roots once a day. During the winter, it was grown on a humidity tray under a T-5 grow light.

The issue is that while it does put out leaves and roots, it doesn't seem to be much bigger overall than when I first got it, and it never seems to add additional leaves. It will put out a new leaf, and then the oldest leaf will die off. It seems to put out about 2 leaves a year, but the new leaves haven't gotten longer than 5 inches or so.

Is this normal? Any cultural suggestions are welcomed!

[Brutal_Dreamer]

The key here is that it is crossed with Paph. sanderianum. This is a very slow growing slipper orchid. Patience.

cheers,
BD

[Laura81]

So it's pretty normal for Paph sanderianum and its hybrids to form new leaves, while not necessarily growing larger in overall leaf-span? Just wanted to make sure I'm not doing anything dumb with it as far as culture goes.

[Brutal_Dreamer]

So it's pretty normal for Paph. sanderianum and its hybrids to form new leaves, while not necessarily growing larger in overall leaf-span? Just wanted to make sure I'm not doing anything dumb with it as far as culture goes.

Normal for the ones I've grown and am growing.

cheers,
BD

[Abrielle107]

It's summering OUTSIDE!? How? With our soaring temps of late?

[Halloamey]

Though Sanderianum and its hybrids are slow growers, 4 years is a long time for a plant to remain of the same size. I have 6 different Sanderianum seedlings that I bought last year. Though I grow in very different conditions and the genetics may be different considering the other parents of the cross, I have had remarkable growth. I also observed that the number of leaves in the fan seems to remain consistent just +/- 2 leaves, the new leaves they produce are progressively bigger. I will ask my mom to take a few photos so that I can share them with you. What occurs to me is that may be your plant is just recycling the nutrients, so there is nio net growth. From the photo it seems it is getting more light than necessary and a bit water stressed. I have been using slow release fertilizer with my Paphs and have good results with it, as it provides controlled low levels of fertilizer at every watering.

[Laura81]

Unfortunately, I have pretty much no sunlight in my apartment during the summertime, so all the orchids get to go out on the patio, which is shady except for a couple of hours in the morning. The warm temperatures and humidity seem to be very helpful for all the other orchids, as they all are in active growth.

I have seen a lot of conflicting information over how much light P. sanderianum prefers. Some say that they need lots of bright light, others say more shady conditions are best (compared to other multi-floral paphs). I'm always really careful not to over-fertilize, since they are very sensitive to salts. Please message me with the name of the slow-release fertilizer, if you don't mind.