Mounts outside. Roots grow thinner

[Tschimm]

Three weeks ago, I put most of my plants outside.
My Brassavola venosa grew roots like crazy when it was inside. But since its outside the roottips grew very much thinner and towards the mount.
That happened with other Brassavolas too...

Humidity inside was constant 75-85%
Outside its about 45-70 during day and 70-90 during night.
Temperatures inside where 18-22C
Outside 15-25C
The mounts are hanging under a tree and get full sun in the morning.

Does anyone has an idea why this is happening ?
Is it because they got more water as usually? (It was often raining)
The roots also seem to turn towards the mounts.

[Ray]

Pure speculation on my part, but I would credit a reduction in water uptake and/or greater drying rate. Additional air movement and lower humidity will do that. The reaction to grow toward the mount is natural - that's where the plant more handicaps anchors itself and where detritus accumulates, holding moisture.


Ray Barkalow
firstrays.com

[Tschimm]

Thanks Ray.
But if I was an Orchid and there is a reduction in water, I'd grow a thicker velamen, not a thinner.
Or do you think the plant is dehydrated and can't grow thicker roots because of that ?

The plant seems to be ok. Many new growths.
I'm not worried, just curious:-)

[My Green Pets]

It's the sun, the roots have been exposed to the sun suddenly and they can't handle it.

[katrina]

I've seen this at this time of the year too and I've always just chalked it up to the root tips growing so fast that the velamen is having trouble keeping up w/the rapid growth.

As long as you don't bruise or damage the roots, in time you'll likely see those areas "fatten up".