Why do you say not to mist plants?

[h_sto...@yahoo.com]

Hi Dennis,

This is Helen from Guatemala again. I want to thank you for your past
advice and help. My orchids are doing great, except the masdevallia
lost a leaf to a green caterpillar before I noticed it (the little
guys are attacking my rooftop container garden these days). The
dendrobium has a promising looking shoot and the oncidium is growing
what I assume is a new pseudobulb (a little green egg shaped thing at
the side of an old pseudobulb).

I have read the recent posts and notice that a couple of times you
recommend against misting plants. Is this a general recommendation,
or just for humid indoor envoronments? I mist all of my plants to
varying degrees depending on their different needs, except of course
during the rainy season when it would be totally redundant. I have
read especially that orchids should be misted frequently or kept on a
pebble tray; I have been misting them. I don't mist them at night, or
on frosty mornings, but I also don't worry about misting them in the
afternoon since it's always breezy on my terrace.

Thanks as always for the help! I do appreciate it and enjoy having
someone to share my successes with.

Helen

[dennis...@aol.com]

Hi Helen:

Glad to hear your plants are doing well! People generally mist in an
attempt to maintain a high humidity around their plants, but during
those times when humidity is really low it is such a temporary fix as
to be a waste of time. When the weather is hot in the summers here
(the SF Bay area)the humidity tends to get very low. Misting may raise
the humidity around the plants for a few minutes so you think you are
helping but you are really not. In the winter when the heat is on it
is the same story. In areas where air conditioning is used, misting
also only provides a brief spike in humidity.

Then when it is cool or cloudy, misting may cause leaves to stay damp
for too long and encourage fungal problems. The only plants I like to
see misted frequently indoors are mounted plants, where the roots will
tend to dry out very quickly. And mounted plants can utilize the
misted water.

I would much rather see people mitigate humidity problems with
humidity trays, humidifiers, houseplants, groupings of plants, plants
in clay pots, fresh air, and things like that. Then they can mist and
shower their plants when they water them, making sure they are dry by
nightfall. Many orchids will do just fine with a relative humidity
that stays between 40% and 60%. In all the years I have grown orchids
indoors, I have never misted them habitually, and have never had
humidity related problems.

Outdoors or in a greenhouse, where air circulation is good and plants
are certain to dry off quickly misting is fine. It is a good technique
to "freshen" the plants when it is hot, and to keep them from drying
out too quickly. It also keeps the leaves clean and can discourage
attack by mites.

Sincerely,
Dennis

[h_sto...@yahoo.com]

Thank you, Dennis.

I have always had a misting habit even when I lived in the US and kept
my plants indoors, and I must admit I have wondered about how long it
could have an effect! During my vacation I could mist several times a
day, but work schedules interfere with that. I have always had good
luck with plants, but my three current orcids are my first try at
orchid care. I got a hose recently and have been wetting down the
cinderblock wall where the plants are hung, thinking this would
probably raise humidity longer than just misting them. When the rainy
season comes in a month or two, it all gets easier!

I appreciate your comments and help, and what you say makes lots of
sense!

Helen