Laelia lobata v. Alba - active root tips, but shriveled new roots

[tuandatn]

Hi again!

I recently bought a Laelia lobata v alba, bareroot and severely dehydrated with very few viable roots. The pseudobulbs were terribly depleted, almost completely flat. Potted it up in a plastic pot with leca (non s/h), and laid a layer of sphagnum moss to keep humidity around the rhizome, and for a soft landing for any new roots. It started putting out roots very quickly but I've noticed that when the velamen starts to set, the roots appear shriveled, as though dehydrated. Anyone have a sense of what is going on, and whether this is a cause for concern? One of the new roots has developed a brown spot, but it appears to be dry, well demarcated and not spreading, so really my major concern is why supposedly healthy new roots with active tips would seem shriveled, even with sufficient moisture from the sphagnum. Could it be that since the orchid as a whole is dehydrated, even the new roots show signs of dehydration as the plant recovers? I've also fertilized lightly (half strength, weekly), but could it be due to excess fertilizer? Can't tell if it's in happy conditions or not!

Thanks for any and all input/advice.
TuanDat

[estación seca]

That may happen if the plant wobbles and scrapes the root tip on a piece of medium or the pot; if it isn't watered often enough; if humidity is low; if tiny bush snails or other pests eat root tips.

What is your relative humidity?

[tuandatn]

Not sure about relative humidity as I don't have means to measure, but the sphagnum is right there at the base of the rhizome and I have kept it fairly moist--it never dries completely, and I mist often. I can't imagine how I would be able to provide any additional humidity given my growing space.

It's especially odd because the root tips are all perfectly intact and going strong! It's only after the velamen sheath sets in (not sure exactly how to phrase this...) that the roots appear shriveled. I've dealt with snails before so sprayed hydrogen peroxide on the bareroot plant before repotting, but will certainly keep an eye out for pests! I was mostly curious if this pattern of root abnormality is clearly indicative of any particular ailment, but it sounds like it may not be!

[Louis_W]

Seems normal to me...

[Roberta]

Looks normal to me. Make sure that it is firmly potted, so it doesn't wobble, and let it do its thing. I grow this species in a wood basket with large bark, It's a Catt... likes to dry out between waterings) It is a root machine.

[tuandatn]

Originally Posted by Roberta

Looks normal to me. Make sure that it is firmly potted, so it doesn't wobble, and let it do its thing. I grow this species in a wood basket with large bark, It's a Catt... likes to dry out between waterings) It is a root machine.

I like root machines! A couple questions for you:

I've heard it can be a shy bloomer--anything you've noticed that increases the likelihood of it flowering regularly?

Unfortunately it was barerooted before the newest pseudobulbs were finished growing. The two youngest pseudobulbs have completely halted growth, are roughly 1-2in long, and less than pencil thick in diameter--they are fairly flimsy. Do pseudobulbs that have halted growth ever re-initiate growth, or is it kind of like once it stops, it stops? I've noticed new eyes bulging and developing, so the plant is growing, but not the two pseudobulbs that were mid-development.

Finally, is there retrograde hydration of pseudobulbs? That is to say, if the only roots are on the front of the plant, as the root system develops, will if rehydrate the older shriveled pseudobulbs to any appreciable extent and plump them up, or should I resign myself to the flat, wrinkled old pseudobulbs?

Thanks so much! Very interested to hear your experience with the lobata. I love the alba form, and have my eyes out for the concolor 'Jeni', but it's very difficult to find anywhere!

[Roberta]

Remember, ideal potting time has nothing to do with development of GROWTHS... it's all about roots. Fortunately this species is not as picky about being potted/barerooted at the wrong time. It will recover. The old pseudobulbs are the plant's reserves. They lose roots and shrivel in the normal course of things, in the meantime get the plant through the rough patches. IF you don't have a good root system, leave all the rootless p-bulbs, you can clean things up the next time you repot it, in a couple of years. By that time the rootless old p-bulbs will be shriveled and brown, no worries, force of nature.

I don't know how well it performs in "captivity" ... in my southern California back yard it blooms most years (got more reliable as it got larger), it gets whatever Mother Nature throws at it in terms of weather. It gets the same treatment as the L. purpuratas (meaning no pampering). Maybe not quite as reliable as the purpuratas, but pretty good and getting better.

Here are a couple of photos of mine from this year, it is just finishing its bloom.

[isurus79]

The roots look fine to me, but ES is correct that bush snails can cause that kind of damage. No need for hydrogen peroxide on the roots, in fact, I would suggest removing it altogether from your orchid care regimen. I've seen it do nasty things to roots and doesn't actually target what you want it to.

Lobata grows fully exposed to sunlight on the cliffs above Sao Paulo and definitely needs high light to bloom. I grew it next to my Cattleyas in strong Texas sun and it didn't bloom. I put it in a much brighter place and it blooms just fine, so you'll want to hit it with tons of light to get flowers. No need to rush though. I'd get those roots roaming throughout the pot before hitting it with crazy bright light.

[tuandatn]

Originally Posted by Roberta

I don't know how well it performs in "captivity" ... in my southern California back yard it blooms most years (got more reliable as it got larger), it gets whatever Mother Nature throws at it in terms of weather. It gets the same treatment as the L. purpuratas (meaning no pampering). Maybe not quite as reliable as the purpuratas, but pretty good and getting better.

Here are a couple of photos of mine from this year, it is just finishing its bloom.

Roberta, absolutely stunning!!! I wish I could just throw all my orchids outside, but alas...Mother Nature has a different temperament in New Jersey. There's something about a shy-bloomer that makes it all the more rewarding when the blooms come. I have a few orchids that have been around for years, and only this year have they started blooming (due to maturity, not bloom shyness), and it's been worth the wait!

---------- Post added at 10:29 PM ---------- Previous post was at 10:25 PM ----------

Originally Posted by isurus79

The roots look fine to me, but ES is correct that bush snails can cause that kind of damage. No need for hydrogen peroxide on the roots, in fact, I would suggest removing it altogether from your orchid care regimen. I've seen it do nasty things to roots and doesn't actually target what you want it to.

Lobata grows fully exposed to sunlight on the cliffs above Sao Paulo and definitely needs high light to bloom. I grew it next to my Cattleyas in strong Texas sun and it didn't bloom. I put it in a much brighter place and it blooms just fine, so you'll want to hit it with tons of light to get flowers. No need to rush though. I'd get those roots roaming throughout the pot before hitting it with crazy bright light.

Stephen, thanks for your insight. I did read about the cliff-dwelling nature, which is why I thought it would do fairly well in non-s/h leca. I wasn't so modest with the light...it is in a south facing window, on a seeding heat mat, about 8inches from a 30W grow light...but under those conditions, it's pushing out roots and 3 eyes are swelling so I just assumed it was happy

Regarding the hydrogen peroxide, what would you recommend in its place, for snails? I've just heard of it recommended to sterilize and kill certain pests when needed. Haven't seen root damage from it so far, but don't want to risk it if there is a safer effective alternative!

[Roberta]

For snails, I don't think hydrogen peroxide would even be particularly useful. A couple of Board contributors have had good luck with strong coffee for bush snails - (nothing else kills them, snail bait doesn't work on them) I am sure that someone will jump in with the particulars.

I actually don't grow my L lobata all that bright - it's under 60% shade cloth. (But in the summer I'm getting sun the entire day, so it's not only intensity, it's duration) I have had it for about 15 years, maybe more. I got it as a division (not a seedling) but it still took a few years to get to the "reliable" stage. So, patience... You obviously have to protect it in colder weather, but actually in the summer, it should be pretty happy outside, loving heat and humidity.