Help, something is blistering my orchid cactus leaves. Picture is
posted on alt.binaries.pictures.gardens. I've got two or three varieties of
something Wife calls "orchid cactus" growing in the greenhouse. One (the
most beautiful when it decides to bloom) has this blight that I can't seem
to slow down. I don't want it to spread into the others until I learn
something about control.
Each little spot seems to start with a little watery blister, and then
dry up into a much harder brown blister. I thought at first it was some kind
of a bug inside the early stage blister. I popped one or two open and using
a 10x glass looked for something squirming or with legs...... nothing I
could identify.
Is this ailment something anyone knows about? And also I'm sure that
there is a better name for the plant than "orchid cactus"..... maybe some
help there too!

Thanks in advance!
Lynn (really rank amateur greenhouser)

Your plants are epiphyllums, commonly known as orchid cacti. Your condition
is rather common. While it could be caused by sucking insects, the spots are
more commonly caused by either water left on the plants in full sun causing
sunburn (water drops act as lenses magnifying the light to burn small round
patches), or by overwatering at a time of the year when the temps are lower
and the plant cannot use or get rid of excess water. Epiphyllums are rarely
hit by fungi, at least on the "leaves" (stems). And the most common insect
problem is mealybug which is easily seen. Give your plants a winter rest by
reducing water and fertilizer especially if they're not in full sun or
receiving full natural light, depending on your location. Good growing.
Gary
"Lynn Coffelt" wrote in message
...
Help, something is blistering my orchid cactus leaves. Picture is
posted on alt.binaries.pictures.gardens. I've got two or three varieties
of
something Wife calls "orchid cactus" growing in the greenhouse. One (the
most beautiful when it decides to bloom) has this blight that I can't seem
to slow down. I don't want it to spread into the others until I learn
something about control.
Each little spot seems to start with a little watery blister, and then
dry up into a much harder brown blister. I thought at first it was some
kind
of a bug inside the early stage blister. I popped one or two open and
using
a 10x glass looked for something squirming or with legs...... nothing I
could identify.
Is this ailment something anyone knows about? And also I'm sure that
there is a better name for the plant than "orchid cactus"..... maybe some
help there too!

Thanks in advance!
Lynn (really rank amateur greenhouser)

Your plants are epiphyllums, commonly known as orchid cacti. Your
condition
is rather common. While it could be caused by sucking insects, the spots
are
more commonly caused by either water left on the plants in full sun
causing
sunburn (water drops act as lenses magnifying the light to burn small
round
patches), or by overwatering at a time of the year when the temps are
lower
and the plant cannot use or get rid of excess water. Epiphyllums are
rarely
hit by fungi, at least on the "leaves" (stems). And the most common insect
problem is mealybug which is easily seen. Give your plants a winter rest
by
reducing water and fertilizer especially if they're not in full sun or
receiving full natural light, depending on your location. Good growing.
Gary

Thanks for all that good information. The overwatering and/or too much
fertilizer is a condition that is quite possible. We used a LOT of water to
keep the pot heavy enough to keep from falling off the shelf. Dumb, dumb,
dumb gardening, I know...... perhaps lazy is also a factor.
Thanks again!
Lynn

"V_coerulea" wrote in message

Your plants are epiphyllums, commonly known as orchid cacti.
Your
condition is rather common. While it could be caused by sucking
insects, the spots are more commonly caused by either water
left on
the plants in full sun causing sunburn (water drops act as
lenses
magnifying the light to burn small round patches), or by
overwatering at a time of the year when the temps are lower and
the
plant cannot use or get rid of excess water. Epiphyllums are
rarely
hit by fungi, at least on the "leaves" (stems). And the most
common
insect problem is mealybug which is easily seen. Give your
plants a
winter rest by reducing water and fertilizer especially if
they're
not in full sun or receiving full natural light, depending on
your
location. Good growing. Gary "Lynn Coffelt"

wrote in message ...
Help, something is blistering my orchid cactus leaves.
Picture is posted on alt.binaries.pictures.gardens. I've got
two
or three varieties of
something Wife calls "orchid cactus" growing in the
greenhouse.
One (the most beautiful when it decides to bloom) has this
blight
that I can't seem to slow down. I don't want it to spread
into
the others until I learn something about control.
Each little spot seems to start with a little watery
blister,
and then dry up into a much harder brown blister. I thought
at
first it was some kind
of a bug inside the early stage blister. I popped one or two
open
and using
a 10x glass looked for something squirming or with legs......
nothing I could identify.
Is this ailment something anyone knows about? And also
I'm
sure that there is a better name for the plant than "orchid
cactus"..... maybe some help there too!

Thanks in advance!
Lynn (really rank amateur greenhouser)

Water drops cannot act as a magnifying glass.

--

Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8
Sunset Zone 5

On Thu, 29 Dec 2005 08:09:48 GMT
"Travis M." wrote:

[]
]
] Water drops cannot act as a magnifying glass.
]

Travis, you seem fond of unequivocal statements... I'm not
sure if you're trolling or what, but a water drop certainly can
act as a magnifying glass. Imagine the geometry of a drop,
it's easy to see how it acts as a lens.

Don't take my word for it, google "water drop magnify physics"
and follow any link, the first will do.

Just wanted to clear that up for anyone without a physics
degree.

-E

--
Emery Davis
You can reply to ecom
by removing the well known companies

"Emery Davis" wrote in message

On Thu, 29 Dec 2005 08:09:48 GMT
"Travis M." wrote:

[]
]
] Water drops cannot act as a magnifying glass.
]

Travis, you seem fond of unequivocal statements... I'm not
sure if you're trolling or what, but a water drop certainly can
act as a magnifying glass. Imagine the geometry of a drop,
it's easy to see how it acts as a lens.

Don't take my word for it, google "water drop magnify physics"
and follow any link, the first will do.

Just wanted to clear that up for anyone without a physics
degree.

-E

Agreed, but one cannot burn the leaf or plant part it is resting
on. It is far too close.

--

Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8
Sunset Zone 5

"Travis M." wrote in message
news:c2Wsf.3597$yx.3019@trndny01...
"Emery Davis" wrote in message

On Thu, 29 Dec 2005 08:09:48 GMT
"Travis M." wrote:

[]
]
] Water drops cannot act as a magnifying glass.
]

Travis, you seem fond of unequivocal statements... I'm not
sure if you're trolling or what, but a water drop certainly can
act as a magnifying glass. Imagine the geometry of a drop,
it's easy to see how it acts as a lens.

Don't take my word for it, google "water drop magnify physics"
and follow any link, the first will do.

Just wanted to clear that up for anyone without a physics
degree.

-E

Agreed, but one cannot burn the leaf or plant part it is resting on. It
is far too close.

--

Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8
Sunset Zone 5

The water droplet myth explained so even those WITH a physics degree can
understand
Still showing up in some popular garden literature is the notion that
"day-watering" or water droplets can burn plants. The notion says that
sunlight is "magnified by the water drop on the leaf to cause a leaf burn.

Anyone who ever burned ants, paper or anything else using a magnifying glass
and the sun knows that the magnifying glass did not burn the ant if it were
placed directly on the ant. Rather, it had to be held a distance (focal
distance) from the ant to concentrate the sun's rays enough to burn the ant,
paper, etc.

If this notion were true, all gardeners would cover all their plants prior
to every rainstorm.

Farmers would not be able to prevent widespread "leafburn" after rain clouds
gave way to sunshine. The root of this notion may have come from the
effects of applying poor-quality water high in dissolved salts. As water
drops evaporated from leaves,the salts left behind could cause a leaf burn.
This will often happen if the water is from a tap hooked to a water softener
system........and probably a lot of other reasons there would be high salt
concentrations in the water that I'm sure if those who want to Google the
hell out of the day, will be able to find.

The sun just came here Travis, wait 5 minutes and you'll probably get some
too!

Val in Ballard (just south of Travis) Washington

"Valkyrie" wrote in message


snip

The sun just came here Travis, wait 5 minutes and you'll
probably
get some too!

Val in Ballard (just south of Travis) Washington

It didn't last long.

--

Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8
Sunset Zone 5

Sorry, Travis, but I partially disagree with you. While your general
statement is true, there are specifics that can certainly vary.
First, you do not have to be at the focal point for damage to occur,
particularly over time. Heating of the tissue under the droplet can cause
necrosis. Secondly, the water droplet may be almost spherical on hydrophobic
waxy surfaces thus shortening the focal length. And thirdly, the thickness
of the waxy layer can add more distance to the focal distance and in effect
raise the focal point closer to the surface. While it's agreed that this is
probably not the cause of this epiphyllum's problems, it's certainly not out
of the realm of possibility, which you seem so certain of, for other cases.
Gary

"Travis M." wrote in message
news:c2Wsf.3597$yx.3019@trndny01...
"Emery Davis" wrote in message

On Thu, 29 Dec 2005 08:09:48 GMT
"Travis M." wrote:

[]
]
] Water drops cannot act as a magnifying glass.
]

Travis, you seem fond of unequivocal statements... I'm not
sure if you're trolling or what, but a water drop certainly can
act as a magnifying glass. Imagine the geometry of a drop,
it's easy to see how it acts as a lens.

Don't take my word for it, google "water drop magnify physics"
and follow any link, the first will do.

Just wanted to clear that up for anyone without a physics
degree.

-E

Agreed, but one cannot burn the leaf or plant part it is resting on. It
is far too close.

--

Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8
Sunset Zone 5

On Thu, 29 Dec 2005 08:09:48 GMT, "Travis M."
wrote:

Water drops cannot act as a magnifying glass.
Nice to come back after a hiatus and find you still don't know shit
from shinola!

http://www.google.com/search?hl=en&q...gnifying+glass

"Tom Jaszewski" wrote in message

On Thu, 29 Dec 2005 08:09:48 GMT, "Travis M."
wrote:

Water drops cannot act as a magnifying glass.
Nice to come back after a hiatus and find you still don't know
shit
from shinola!

http://www.google.com/search?hl=en&q...gnifying+glass

Water drops on a leaf for instance cannot magnify the suns rays
and damage the leaf.

--

Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8
Sunset Zone 5

Sounds like edema to me, and not unusual on thick-leaved plants. Check this
out to see if this looks like your plant's problem:
http://www.uwex.edu/ces/wihort/gardenfacts/XHT1116.pdf

Suzy O, Zone 5


"Lynn Coffelt" wrote in message
...
Help, something is blistering my orchid cactus leaves. Picture is
posted on alt.binaries.pictures.gardens. I've got two or three varieties
of
something Wife calls "orchid cactus" growing in the greenhouse. One (the
most beautiful when it decides to bloom) has this blight that I can't seem
to slow down. I don't want it to spread into the others until I learn
something about control.
Each little spot seems to start with a little watery blister, and then
dry up into a much harder brown blister. I thought at first it was some
kind
of a bug inside the early stage blister. I popped one or two open and
using
a 10x glass looked for something squirming or with legs...... nothing I
could identify.
Is this ailment something anyone knows about? And also I'm sure that
there is a better name for the plant than "orchid cactus"..... maybe some
help there too!

Thanks in advance!
Lynn (really rank amateur greenhouser)

Thanks to everyone for all the help. This last one about edema, and the
pictures on the "link" seem to fit quite well. I've pretty near stopped
watering the one plant with the problem, and it has grown some new leaves
(is that what they are called?) without the blistering. I'll try to be more
aware in watering when it begins to heat up again here in NW Washington.
Lynn

"Suzy O" wrote in message
...
Sounds like edema to me, and not unusual on thick-leaved plants. Check
this
out to see if this looks like your plant's problem:
http://www.uwex.edu/ces/wihort/gardenfacts/XHT1116.pdf

Suzy O, Zone 5


"Lynn Coffelt" wrote in message
...
Help, something is blistering my orchid cactus leaves. Picture is
posted on alt.binaries.pictures.gardens. I've got two or three varieties
of
something Wife calls "orchid cactus" growing in the greenhouse. One (the
most beautiful when it decides to bloom) has this blight that I can't
seem
to slow down. I don't want it to spread into the others until I learn
something about control.
Each little spot seems to start with a little watery blister, and
then
dry up into a much harder brown blister. I thought at first it was some
kind
of a bug inside the early stage blister. I popped one or two open and
using
a 10x glass looked for something squirming or with legs...... nothing I
could identify.
Is this ailment something anyone knows about? And also I'm sure that
there is a better name for the plant than "orchid cactus"..... maybe
some
help there too!

Thanks in advance!
Lynn (really rank amateur greenhouser)