Help! Newbie caring for seedling.
 

Hi! So the newbie I am, I accidentally ended up with 2 very young plants. I tried to look for care information on internet, but most I could find was that young plants require more water.

Any additional tips would be very appreciated!

1. Very young Tolumnia. Came in tiny basket bare rooted. I potted up in bark and sphag. Put a half amount of slow release fertilizer. One baby leaf died off since I got it, but there is new growth that is getting bigger.

2. Very young Oncidium. Came bare rooted. I potted up in sphagnum moss. Bottom leaf dried up, and some of the other leaves are curling a bit inwards. Not sure if its normal? Maybe my humidity is too low?

Thank you in advance for your help! I am attaching photos. They are both very small.

I would take the Tolumnia out of the sphagnum moss right now and read this thread:
Darryl Venables on Tolumnia - DVOS September 2018
They need to dry out every day.

Your home is probably centrally heated right now, warm and low humidity, right? If so I suggest a tiny Oncidium like that would do better in sphagnum moss. Get a fair amount of moss wet. Unpot the plant and shake off as much of the current medium as you can without damaging roots. Wring the moss out as tightly as you can. Wrap moss tightly around the plant's roots. Cram it tightly into the pot.

Water when the top of the moss is approaching crisp. Don't soak all the moss in the pot; just run water over the surface for one second. It will diffuse through the moss and leave it evenly moist.

Tiny Oncidiums can grow in fine bark, too.

Thank you so so much for the quick response!!!

I have gone and repotted the tolumnia in a mesh pot with medium sized bark. Hopefully this will dry out better. Some of the roots were rotted, so I think it was definitely too damp for too long.

I also did what you told me to do with the oncidium. I had no idea you could pack the moss tightly. I thought it always had to be airy! I am already learning so much here.

I watched a lot of tutorials, care videos and read articles, but they all say different things, which really confuses me. I know care is different for different environment, so not all size fits all, but some say oh this orchid likes to dry, and others say, oh they don't like to dry!

It is very helpful to be able to actually communicate and interact with people that give you those tips, so you can ask more specific questions, and they can give you specific answers.

Thank you again, so much! I hope they will do better with the new set up. I wish I could have gotten "easier" orchids to start with!!!

My little seedling/plug sized oncidiums are in a oncidium mix from repotme. They are doing well. I would be super careful with the sphagnum moss as it can rot the roots since it tends to stay wet. My plants are putting out new roots and looking good. I am in the same boat you are in with it being dry. A friend of mine suggested getting an essential oil diffuser (you can get one from Walmart or Amazon for like $20-30) and running it near the plants. I am trying it out and I sat a hygrometer near by and it actually is keeping that area nicely humidified at about 55%. It was also suggested to me to get a seedling/germination heat mat (but you don't have to) and did that. I don't know if its made a huge difference or not, but the plants seem happy for now.

Good luck with this all. I have had Phalaenopsis orchids for years and decided it was time to branch out....not knowing that plug care is a bit different than my mature plants. So far, my plants are doing ok!

People make the mistake of getting the sphagnum soggy wet. Unless the plant uses the water within a few days, yes, the roots may rot. If used as I described it works very well for tiny seedlings.

Hi! I'd never heard of using essential oil diffuser. I guess it acts as a humidifier? I didn't mean to get a seedling, and I got it by an accident in a way (it came as a "bonus" with my Tolumnia order). I hope I can keep it alive! I'm definitely not skilled enough to raise a young orchid!!! Sounds like you have a lot more experience than me with orchids, so you have a better chance of success! Hope it will grow big, and you can show us the blooms in....4 years? Hahaha.

Seedlings are quite a bit more challenging imo and explaining what is more challenging or how to overcome those challenges is hard to describe, also most of us are also learning as we go still. I could link some basic care guides but you've read those.
As long as you know how much light to give, the right temperature for it and how much to fertilize it then the challenging part is figuring out how to water it.
ES has explained his method. Others never compact their moss. Then others don't use moss at all. There are lots of different media's that can be used.

Some media's can be overwatered so you have to water those carefully or the roots will rot. My preferred method is using media's that are hard to overwater. You can pick the right mix so that if you give it a quick spray once a week till a bit of water runs out the bottom, that will keep enough for a week but you couldn't do the same with sphagnum as ES described it would get too waterlogged.
But finding the right media for the environment and the plant you have comes from trying out different things unfortunately.

People always so do x y and z and never to repot too many times.

But what if the person trying x y and z doesn't follow the instructions 100% and ends up overwatering. Or the media is too compact. Long term the roots would rot. It is a very complicated matter if one gets really technical about it but it does help to understand what it is we as growers are trying to achieve - more so I find than what substrate we actually use. Sometimes the substrate size is more important. Are we using slotted pots that dry faster or regular pots that need more aeration because they have less ventilation holes?
Those are the important aspects we need to think about and get better at with every orchid we grow. We learn and try to do things better for the next orchid we get...

Here is an article to help explain (yes boring stuff but very good). The article is all about air porosity and talks about plants in general. As we know orchids need even airier substrates than regular houseplants- I would estimate up to 40% for Cattleyas, compared to the 20% they talk about in the article:
Air Porosity and Water-Holding Ability of Media Components - Sun Gro Horticulture

edit: the article mentions pore space, air holding capacity and water holding capacity.

To understand the article it helps to know that the air and water holding capacity is when fully saturated. So for example rockwool has 65% water holding capacity and 25% air holding capacity which gives a total porosity of 90% (65% +25%)

When the media is completely dry all pores will be filled with air. When the pores are completely saturated with water then some pores get filled, some retain air.

Perlite has a total porosity of 65% which is comprised of 40% water and 25% air when fully saturated.

bark has a porosity of 80%, 60% water and 20% air at capacity

coconut coir has roughly 90% posrosity, 80% water 10% air.

An interesting proerty of cocnut coir :

although I am not a fan of coir, it holds 80% water vs 10% air so can be dangerous to use.

Moss varies widely, but genreally has something around 85% porosity, 70% water and 15% air

@Shadeflower,

Totally agreed. I'm still trying to figure to what works best in my environment for those plants. It will certainly be trial and error. Hopefully I can find the best setting for those orchids before they end up dead! But if they do, their death will not be in vein. I will learn and do better with the next one! :)

Thank you so much for the advice and link to information! Learning about orchids has been very interesting and intriguing. I'm enjoying it quite a bit.

BTW I'm using the tiniest pots for all my plants with mostly terra-cotta or net pots, so that I can avoid overwatering. Seems to work for me. The oncidium, I put in a 2 inch plastic pot with the sphag, and I'm watering it very lightly, just enough to be moist for the last 2 days. I will see how it responds. Hopefully it will do better!

Unfortunately, I haven't figured out the fertilizing part quite yet. This topic is EXTREMELY confusing, and it will take me a while to find what works for me. Nothing seems straightforward, even fertilizers!!!!!!!!

When it comes to fertilizers no person on earth agrees on the same thing it seems.

Most just buy one from the shop, job done. Very few of us seriously think about fertilzing and those that do, ie me and Ray mainly completely disagree and use widely different formulas.

The only thing I think we agree on is that they need plenty of micronutrients - as much as regular houseplants, they just need less macronutrients.

This is where it gets a bit challenging, you can buy a regular tomato fertilzier, reduce the strength by 4 to make it less strong but then you have reduced the amount of micronutrients by 4 also so although you will be feeding the right macronutrients long term they seem to lack the micronutrients then

If you feed the full strength feed they will get enough micronutrients but way too much macronutrients (macros' increase the Total dissolved solids (TDS) far more than micros)

Ok so that much (I think) we agree on which is why it is beneficial to add seaweed extract which contains a lot of micronutrients and vitamins.

I would say seaweed should form the basis of any fertilizer program.

Then what me and Ray disagree on is whether to use a grow feed or a bloom feed predominantly. I have recently switched to a bloom feed for my phals and have never seen more explosive growth. I can't explain it, nobody really talks about what would happen if you feed a high bloom feed while the plant is not blooming. Well it seems they do absolutely fine, leaves grow nice and strong, root growth in improved although I'm only doing the bloom feed for my phals and vanda's, the catts are still on a grow feed.

Now you might ask why am I being so fussy about it? For me it is simple. I tried the MSU feed this year for the first time and for the first time some of my dendrobiums that have flowered for the past 3 years continuously did not flower this year.

Then I lost a couple of plants and I blamed the strength or the lack of the plants had.

Overall a lof of plants started developing brown leaf tips. Leaves started getting darker, leaves started growing smaller and distorted.

I was not happy so I had to change something. Figuring out what had to be changed was tricky. Does one try addig calcium. MAgnesium, calcium + magnesium? I tried those and if the plants are lacking ca or mg then adding them is certainly beneficial but if it isn't ca or mg then adding those can make things worse.

Ok I thik I better leave it at that, I could end up writing an essay on the subject and it is only my opinion with others having a completely different opinion on the matter.

@Shadeflower,

Ahh interesting. I thought everyone was in love with the MSU fertilizer and had no issues. See, every single person says the fertilizer they use works fantastic, some despise the big name brands, some think organic is better, etc. And forget about NPK ratio. Every article and fertilizer has different ratios. I believe AOS recommends 20-20-20, but others recommend one with a dip in the middle... There is the "weakly weakly" method, slow release...

What I've gathered so far is that we want somewhere between 130-200ppm Nitrogen with more Nitrate % than Ammoniacal/Urea. And consensus seems to indicate yes, Calcium and Magnesium are beneficial, esp if you are using rain water or RO water.

I have a feeling I'm just gonna have to try one brand and see how my plants do. Honestly, I've never even fertilized my regular houseplants because before last October, I only had succulents, which I might add that I killed all of but one... but I have learned from my mistakes, and I currently have approx 30 plants that seem quite happy. Hey, succulents are hard!