Sometimes on young plants, we see an odd situation
to new growers.
We will see circumstances where the leaf curls
up into a tube or it rolls over, showing the
underside of the leaf to the light.
Why is it doing this?
Essentially the petal is shading itself, right?
When the petal rolls over, it shades itself,
reducing the amount of light that is striking
the photosynthesis area.
By reducing the amount of light striking the
photosynthesis area, we see a reduced need
for water.
Why does this occur?
The plant is protecting itself from the transpiration
rate that is being induced by the lighting.
So under what circumstances does this happen?
Sometimes we have a young plant that we have
just transplanted.
We’ve taken it away from its gentle fluorescent
lighting.
We’ve now put it under HID lighting, which
is more intense, demanding a greater rate
of transpiration, and the plant is young.
It hasn’t established an aggressive root
mass yet.
The root zone is unable to take up enough
water to meet the transpiration rate that
the aboveground atmosphere is inducing, so
there’s not a huge amount of things you
can do about this.
You could spray a cloning wax like an anti-transpirant
to reduce transpiration that would make it
a little bit easier for that young plant to
handle the rate of photosynthesis that’s
being induced by the lighting.
You could back the lights off, so it’s not
as intense.
You could raise the humidity a bit, but at
the end of the day, this is not a serious
problem.
New growers look at this and they say, “Oh,
my goodness!
What’s happening?”
But this is really one of the easiest problems
you could deal with.
All you need to do is let that root mass dry
out.
In other words, don’t overwater it because
as the root mass dries out, the roots are
really going to rip through that medium and
establish their size.
Then the next time you water that medium like
if you use a root stimulator, you’re going
to have much more root growth in that medium
to take up the water that you’re giving
it, which will then match the aboveground
rate of transpiration.
They will definitely grow out of this minor
problem.
Don’t be too concerned.
Sometimes this can happen with plants that
are growing super fast.
If the aboveground growth is so fast, then
it’s outpacing the root development, you
can see the same problem.
Just remember: it’s not super serious.
You can back off your lighting and generally
plants will grow out of this problem.
