From Sphag Back to Bark

[sandra]

Back in March I bought an Oncidium croesus and potted in bark, charcoal, perlite. A while later I noticed the ps.bulbs seemed shrivled and I wasn't overwatering or underwatering. Since I had some luck with sphag (on onc. and dend. seedlings), I changed the media to sphag for this plant. It began growing new ps.bulbs, the leaves looked healthy except for a few here and there that turned yellow. Now it's about 3 months since I've had it in sphag. and decided to check the plant out just a little while ago. ALL roots except where the new growth is, have rotted....completely! There are plenty of new roots where the new growth is but the entire plant aside from that has lost all it's many roots.

I don't get it how some people have such great results with sphag while others, don't. I understand the other dynamics that come into consideration when using this media but I thought the compensation in moisture obtained from sphag. would work in the plants best interest. I let it dry between watering but not completely and am wondering if I kept the plant too wet afterall.

It's back in bark, charcoal and perlite now and will stick to sphag. for seedlings ONLY! Live and learn.

[Michael_Exler]

Think of it as the circle of life.
Here is a dirty little secret most people dont know.
Once a SB has reached maturity is usually does not grow new roots, the roots come from new SB growth to support the new SB.
the old SB, now concidered back bulbs help nurish the new growth until the new SB has roots to support itself.
There for your back bulbs really dont need roots cause they are done growing.
I would be concerned with rot, but the natural course of an orchids life, such as Onc. and Catt. is to move forward and anything left behind becomes old anchorage.
I hope this helps

[kmarch]

Like pretty much all of us have to do as we go, it sounds like you are learning what kind of mix gives the best results given your watering habits and your conditions (temps humidity, etc., etc.).

As an aside, a funny thing about our habits, in my experience I have noticed folks are much more willing to change the mix that they grow an orchid in than it than they are to change their watering habits or their conditions unless they have a greenhouse). In the home growing conditions are sometimes hard to change, understandably but of those things that we can change, our habits, or the potting mix, many growers are much more connected to their habits.

[new_keiki]

Michael, I have a question. For how long can the mature bulb survive without roots? Actually I notice that with my oncidium I just thought the bulb isn't healthy. Btw, how many times does a bulb flower? Thanks in advance

[sandra]

Originally Posted by Michael_Exler

I hope this helps

Thoroughly Michael. Thanks much!

Originally Posted by kmarch

...many growers are much more connected to their habits.

Good old habits, those instinctive actions are really addictions almost impossible to change without going through withdrawls. I've got a heavy hand with watering. I should have known better.

[Anton]

As I say, you're ALWAYS on a learning curve with orchid growing, some of my plants do well in sphag, others don't, some do well in coir, others don't so i keep learning.

BUT, the skewers are the best thing since sliced bread.

[kmarch]

"ALWAYS" is right Anton. 10+ years here and still learning. I've spoken to growers who've had 20-30+ years of commercial experience saying things like, "I just heard that _____ grows his _____ using ____ so i tried it this year and I've got twice the growth. I can't wait to see what the flowers will be like this year!" Learn, learn, learn. It's one of the things I love most about the hobby. That and, well, the flowers of course.

[fred]

I must admit as most of us know I grow about 70% of my orchids in sphagnum moss I love the stuff.
It is hard to beat fresh sphag.

I strike my ps-bulbs in sphag plus all my oncid,s, odonts, mini catts sarcochilus, Masdevallias, and a few others are all grown in sphag.

What i find with growing in sphag the skewer method does not come into the use of growing in sphag.

Having said that the skewer does work well with bark medium.

[Cynthia, Prescott, AZ]

Well, there is also the possibility that the older roots were not of a type that was good for moss. There are changes that take place in roots when they first grow that are adaptations to the conditions they find as they grow. This is why the switch to semi-hydroponics is so hard on orchids as the roots are not the right type for low moisture at the top of the pot, and higher moisture at the bottom, and even some of the roots at the bottom will adapt to growing in water. So, you may have had a transition problem. Now, I hope you don't have another transition problem going back to bark with those new roots. If the new growth producecs a lot of roots, it should provide all the needs of the plant. Don't remove bulbs just because they have no roots. It is best if a plant has three bulbs in a row to store energy for the future activities of the plant.