Green orchid root tips turn non-green - Orchid Board

Ross · #1 (**permalink**) 06-20-2007, 02:16 PM

This question regards several orchids in varying culture regimes (terrarium, non-terrarium) whose previously green root tips have ceased being green and end up just white like the rest of the root. I have one orchid (Amesiella monticola) in an orchidarium, whose previous fat warty white roots with new green tips, ran up against the continuously damp (not wet) sphagnum, then quit growing. They are not rotted, just blunt like something ended the growth. I have an Angraecum dideria in a mesh pot with bark and it had previously active growing roots (same fat warty appearance) that have started to lose the green end. Again, no signs of rot, drought, chewing, etc. I have a Sophronitis cernua with new active growth and one has a new root with lotsa green on end other growth had new root, but the end has stopped growing, but is still white. In all cases the roots get the green color you would expect after watering, it's just that they misteriously quit getting longer.

Is this all normal, or is it related to some cultural issue? Anyone else run into this before? I have a call in to Andy at Andy's Orchids, but he pulls plants for shipping on Wednesday and isn't available, so I thought I pick you all's brains

Oscarman · #2 (**permalink**) 06-20-2007, 03:06 PM

My experience is that the green tips are present only when the plant is in active growth. Otherwise the roots are all white, with the velamen covering all the way to the end.

Ross · #3 (**permalink**) 06-20-2007, 03:34 PM

Thanks Dave, but I think something else is afoot here because one (the Sophronitis) has one active growing root and one that quit. I know you are right because in general I see the same thing, but on these three something else needs to be looked at.

Charles · #4 (**permalink**) 06-20-2007, 06:29 PM

This is why I theorize that the plant will grow roots where it "thinks" it needs them. Responding to light, temp and moisture (all either more or less) the plant will shape accordingly. I have orchids that seem to "react" to different needs and stimuli.
I also know that conditions like dormancy and vigorous growth do come and go. Fertilizer can also cause a plant to "stop".

cb977 · #5 (**permalink**) 06-20-2007, 07:00 PM

Ross, send them down to me...I'll see what I can do

Ross · #6 (**permalink**) 06-20-2007, 07:03 PM

Quote:

Originally Posted by Charles

Fertilizer can also cause a plant to "stop".

I think you may have hit on the situation. I just talked with Andy of Andy's Orchids and he was not concerned. The reason was, he thought the plant was just getting accustomed to the local conditions. Well, the local conditions change as the the humidity and watering change

So I think we have a situation where the roots are healthy, they just aren't lengthening at a significant rate. This could maybe be temperature, humidity, etc.

Helen · #7 (**permalink**) 06-20-2007, 08:49 PM

I was just wondering about that today. The new orchid I bought on Sunday had three arial roots with nice long green tips, 2 on one side and 1 on the other....the single one's tip just seemed to scrivel up and stop, just since Sunday...I did fertilize the plant and I thought maybe I damaged the tip when moving it about or something like that....I was a little worried about it today though....ummm

Dorothy · #8 (**permalink**) 06-20-2007, 10:52 PM

The small aerial roots of my vanilla planifolia also did the same... dried and shrivelled up after I bought it in April this year. I definitely feel it was due to it's environment change. Now that it has adapted (and I have tried to give it what it needs), it's aerial roots are spurting all over the place

Sometimes a little patience pays off

Helen · #9 (**permalink**) 06-20-2007, 10:55 PM

I probably have to agree with you Dorothy...from a greenhouse environment to my air conditioned home...ouch! I have trouble getting the pot to sit upright because the pot is so small and the roots are outside the pot touching the table....Cloud's told me NOT to repot for 2 months until the orchids acclimatize to my home. it's going to be a rough 2 months...cuz I don't know what those little roots are going to do...maybe I should find a way to hang it up...LOL

Leisurely · #10 (**permalink**) 06-23-2007, 04:08 PM

Something that I have noticed with my plants is that if I grow them on the dry side they produce an abundant root system and the bulbs and canes are not as plump. I have a few cats growing in sphagnum that are kept moist for the most part and the root system is not as extensive but the pseudobulbs are so plump that some have split. The plants are probably just responding by saying that they don't need to make a lot of roots with all this moisture.