humidity and tropicals

My next expirement to master my greenhouse Humidity
have any of you tried to control low humidity in an arid region ?

(see below for my conditions)

I have ordered (with a 30 day satisifaction guarantee)
6253 Charley's Portable Fogger
is a Charley's exclusive item, available only from Charley's Greenhouse Produce cloud-like mist
Imitate the foggy mists of tropical jungles! Your plants will thrive in this super-fine mist that hangs in the air and drifts through the foliage. It is very effective for cooling, as well.
Ruggedly built for long life, the centrifugal fogger is maintenance-free - no nozzles to plug up! Coverage is up to 250 sq. ft. Portable: simply fill the 1-gallon reservoir, or use parts included to connect built-in float valve to garden hose for full-time water supply. For automatic control, add a timer or humidistat.

2 gph out put. Rotate exhaust head to direct for, or remove head for maximum output. Size: 14" diam., 19" H. 5-ft. grounded power cord. 115 volts, 0.9 amps. Micron size is 20 microns, with fogging head it is 10-15 micron.

“I just love my new fog machine. I can testify that it really does do what it says it does. I am 100% thrilled with it. It wasn’t long before it began to make a real difference in the growth of my orchids.”
– Ralph Velez, Westminster, CA

and a 6147 Prewired Humidistat
Automatically controls your humidifier or misting system. Ready to use:
1. Plug humidistat into 120-volt outlet
2. Plug your humidifying equipment into the humidistat
3. Turn the control dial to desired setting.
Range 20% to 80% relative humidity. 6 ft. power cord with series plug included. Use with line voltage. Positive OFF setting. 125 VAC. 6.5 amps.

inside my greenhouse ======
Temp 69 - 61 degrees with two 1500 electric oil heaters running
RH has been 50 - 37 % now with two household humiditifieds running
(total output of .5 GPH)
I basically have 3 types of plants in my greenhouse
1. Bananas - which are dieing one after another
2. Elephant Ears - which are hanging on but not growing
3. Brugmansia - which are doing better than the others and have a few white flys which I am spraying as discussed on other threads

my climate =======
I am in zone 9 - 15 miles east of Sacramento California
for the past month my weather has been as follows
rain 3.7 inches
max wind 38 mph
low temp 25 degrees high temp 85 degrees
Rel Humidity 32-94

currently it is 2 pm and it is 50 degrees with a RH of 38% outside

other sources of advice =====
several sources that warn about excessively low humidity ======

1. "Greenhouses for Homeowners and Gardeners" ISBN 0-935817-51-4
Very dry air can reduce rooting of cuttings and cause leaves to wilt
Where plants are grown in very dry conditions, transpiration from the leaves will be greater than moisture intake by the roots. The growth and vigor of the plants will be reduced.

2. "Ortho's All about greenhouses" isbn978-0-89721-463-6
When Humidity in the Greenhouse stays below 50 percent for long peoiods, plant growth suffers, because leaves lose water faster than they can replace it.
Most plants do well with a relative humidity from 50% to 70 percent, but many tropical plants prefer 80 percent.

3. all references spend considerable time warning as Tigerlilly did of the risks of too much humidity

I'm not sure that lack of humidity is the reason why your plants aren't doing well. There are lots of people in California who grow EE's, bananas, and brugs without artificially increasing the humidity. Not to say that they wouldn't also do fine if you increase the humidity, but those plants can definitely be grown with CA's natural humidity levels so if they're looking really unhealthy there's a good chance there's something else going on.

the ones growing outside (prior to the last few cold nights)
look much better than those in the GH

differences
outside very wet, colder and more humid !

so I don't think wetter is better ??
nor colder better ??
so my last guess in the low humidity !

I still don't think it's lack of humidity that's causing your problems. As I said before lots of people in California grow those plants without adding humidity. And lots of people here overwinter them in greenhouses without humidifiers and don't have problems. Some extra humidity certainly isn't going to hurt them, but I think you need to keep your eyes open for other problems. When I have problems with plants in the GH looking unhealthy, it's usually either bugs of some sort (you already mentioned you had whiteflies on at least one of them), or a bit of sunburn on the leaves if their spot in the GH is sunnier than where they'd been before, or heat stress if the GH got too hot during the day, or a watering issue (too much or too little). I'd say my most frequent problems are watering related, I find it's a lot harder to get the watering correct in the winter in the GH than it is for my outdoor plants in any season.

I'm not trying to discourage you from getting your humidity up, as long as you're careful not to make it too high your tropicals will enjoy having a bit more humidity. I just don't think lack of humidity is causing the problems you're seeing so I'm encouraging you to consider other things as well.

I know my watering is not correct
they always seem to be wet in the greenhouse
the surface of the soil and the leaves look and feel dry
but just below the surface the soil is very wet

so I don't water very often 7-10 days between light waterings !

I added pictures to my website so you could the difference
Oct 27 vs today http://www.rader.org/garden/GH_humidity.htm
as I look at the pictures it is worse than I thought !!

The browning edges on some of your leaves look more like salt/fertilizer buildup to me rather than damage from low humidity. And some of the yellowing and then dying leaves look like it could be overwatering.

Given what you said in your previous post about how the soil a few inches down stays really wet and you just give it a really light watering every week or so, those conditions are perfect for creating root rot and salt buildup. The EE's may not mind having wet feet, but for most plants having the soil around the roots stay pretty much constantly wet like that is not good. And when a lot of the soil is still wet and you're just adding a bit to wet down the top few inches of soil, salts from fertilizer, hard water, etc will tend to build up in the soil. What you need is some better draining potting mix, that way nobody will have wet feet, and when you do water, you'll be able to water more thoroughly and flush out those salts. I'd recommend checking out tapla's sticky threads in the Container Gardening forum, he explains very well about water movement in containers and there are some good recipes in there for container mixes that will drain well.

Charlies Greenhouse Portable fogger arrived today
It is a very solid impressive unit !!
I plugged the model 6147 Humidistat into the wall socket and set it on the table
next to my plants
I then connected the water to the faucet, It filled quickly and shut off
I plugged the electrical cord from the Humidifier into the Humidistat
and turned the control knob from off, The humidifier came on at 60%
It really puts out considerable vapor, you would not want it without the humidistat because it really blows the vapor out with it's atomizing screen !
It is cloudy and 50my $7 thermometers indicate at 1:10 pm
north end of table 68 degrees and 55% humidity
south end of table 68 degrees and 58% humidity
after one hour of operation
all fans are still off,
the munidifier, has cycled many times, dial at 60%
my $7 thermometers indicate at 2:20 pm
north end of table 64 degrees and 73% humidity
south end of table 68 degrees and 80% humidity
Outside
cloudy, 50 degrees and 82%
There is still no sign of wetness in the greenhouse !!
---------
The assembly only consisted of pushing the provided 1/4" tubing
into the garden hose adapter and the unit's overflow valve
charlies source [HYPERLINK@www.faran.co.kr]
it is labeled HR50 "made in Korea" Humidifier
the Humidistat states that "Typically 40% - 50% is a normal setting,
depending on owner's preference and plant requirements

ecrane3
In the past 2 months I have only fertilizer once and with time release fertilizer
The bananas are in a soil mix with 1/3 perlite ?

how often do you water them ??

With salt buildup, if you're not flushing the soil well when you water it doesn't matter how often you apply fertilizer, it's something that happens over time so even if you're only fertilizing as often as you're supposed to it can still happen (hard water can contribute as well). As far as the bananas--I'm not an expert on what should be in your potting mix since I don't grow them, I was just going off this comment:

If just below the surface is staying very wet, then you're not getting proper drainage and that can contribute to root rot. And since you're just doing light watering presumably just to wet the top inch or so, you're not flushing things through and that can help contribute to salt buildup in the soil.

During the winter, if we're having sunny weather I typically have to water most of my plants every 2-3 days, but the frequency drops if we have a cloudy rainy spell.

I think I will try watering more often and more quanity
It can't be any worse than I have been doing
I fill watering cans and let them acclimate to the GH before applying to the plants
so the water is the same temp as the plants and the chlorine has disipated

I now have the fans back on
it is 5 pm
the GH is holding at 70 degrees and 70% humidity

outside 48 degrees and 81%

Actually it could be worse--if they already have wet feet because your potting mix isn't draining well, then watering them more often will only make things worse (except maybe for the EE's, I think most of them tolerate wet feet). What you want to do is water less often but more thoroughly, that way you'll flush out the salts better but hopefully won't drown the plants in the process. I'm still worried about the drainage in your containers though, it really sounds like they're holding water too well. I'd really recommend reading tapla's threads in the Container forum that I suggested a couple posts ago.

The 6253 Charley's Portable Fogger $440.00 with the 6147 Prewired Humidistat from Charlies Greenhouse really makes a difference
using the LaCrosse wireless Data Recorder I get the results (see graph attached) every 5 minutes it takes a reading.
I have two of the $7 high/low high low therm/humidity which I validate the LaCrosse

the left half is the day befor installation
the right half is after

the weather outside is the same 30-50 degrees heavy clouds

May I ask how much this cost with the thermostat?

Speaking for myself, it is difficult to maintain the watering conditions in the greenhouse. I too experienced the containers staying wet for a long time. I experimented by doing a few things to fix that.. Like Ecrane says, the drainage in the pots is high on the priority list, so I changed that for this season. I also increased the air circulation by adding another fan. Now I have an upper and lower fan on high. I also put in a green house halide light, (I have a fiber glass roof) and these changes seemed to have brought more balance to the plants.. Things are healthy and growing, pots are drying out every 2 days. I have the plants organized by water requirements, ie plants that prefer to be on the dryer side, and plants that need watering more often. In past years not doing this presented overwatering issues with that group of plants..

Aside from that I'm sure I've only scratched the surface in keeping a greenhouse in balance.!

I only use mine for a couple months a year...so progress seems a bit slow.

the hunidistst cost $89

my experience is the same as yours, the pots do not dry out in the greenhouse
I am now giving them a thurough watering twice a week, even is they are not dry

the entire greenhouse is sprouting and growing much better

That's pretty good! I have two household humidifiers in my greenhouse, which does okay for the most part, but when it gets as cold as it has this week, I take my hose with the nosle and put it on mist, hold it in a 5 gallon bucket and let it mist up the green house. I like the idea of that hunidistst. Glad you posted the information. The 2 humidifiers keep the humidity at about 50 percent if I'm to believe the reading on one of the humidifiers that supposedly calculates the percentage.
I think the key this year is I've kept the heat higher , and the two fans...one hanging from the rafters and the other almost floor level. They have been drying out every couple of days and look the best ever, so something is going right!