Humidity

I am new to greenhouses and have a question about humidity. I mostly am growing mostly tropicals and live in Z9 Ca. How much humidity is to much. The day temp is about 80 and night is about 50 right now. No additional heat . No fans . Just a new greenhouse with automatic window openers and a aluminet cover. How do I tell if its to humid, not humid enough. I know you guys have been doing this for years and I would appreciate any help you can give me.
Thanks Linda

Bought a humidity meter,for 3 bucks at walmart in the hardware department,shows percentages and a comfort zone,which is between
30 to 50 degrees.

I was wondering the same thing, I am in the process of getting my greenhouse built and wanting to start out right and have been searching the web for answers also. I found a temperature/humidity combo thermometer but not sure what is the optimal temps it should read, I will have tropicals and brugs, cuttings in mine to start. Hopefully someone will come along and give some advice.
Thanks for posting
Vickie

Vickie, you and I have similar tastes! I also grow tropicals and Brugs, but, mostly am growing Hoyas now.
I have found my biggest problem to be spider mites in winter. High humidity is the best weapon against them and it is also a big problem in the winter. I am saving my pennies for a mist system, but, that will be awhile. Over the summer, I ran an misting hose around my GH and turned it on 2X per day. Problem in the winter is that the water is too cold to use it. I have several misting fountains running and try to mist my plants by hand whenever possible. Also, I try to mist the GH walls and floor whenever I can.
I have grown Brugs for 10 years. SInce they are spider mite magnets, I have given up on trying to keep them growing through the winter and opted to let them go dormant in the garage. Check out the Bubblers in the Brug forum!

Thanks Mel, I am new to brugs really, I received my 1st cutting last winter and grew one from seed but this last summer they were still to young so I am still waiting for one to bloom. I have just received several cutting now trying to root and I am hooked..Living in Texas I grew a lot of Tropicals so it was a big zone shock when I moved here but they seem to be doing ok.
Hoyas now I have not started any of them yet but I think I would love to try my hand at them, they are so interesting.
Thanks again,
Vickie

The desired humidity that you seek should be determined by the plants you are raising and the type of weather that you have. The 'average' humidity desired by most GH growers is between 50% and 60% humidity. Some plants need more and some require drier conditions....this is where fine-tuning becomes necessary.

Within anyone's GH, there are smaller microsystems that some fussier plants can be placed. I have sections in my GH where it is definately warmer and brighter than other spots. Likewise with sun (footcandles)....some areas are much brighter and some are much more shaded. Plants are placed in the GH according to their requirements, not according to a 'decor' or a 'convenience'.

My greenhouse is set for "Intermediate" conditions, and the GH is primarily for orchids. Most of my orchids require the 'intermediate' conditions, but others like it cooler or warmer, depending on the orchid. Those that like it cooler and shaded, are situation below the benches, where the lower area is cooler and somewhat covered from direct sun.

My GH is fully automated with an Aquafog mister, water, exahaust fan, and a Modine HotDawg propane heater. I use stat controls to regulate the temp and the humidity, and also have an alarm system in place that will sound in the house if the temp goes below tolerance.

The GH is set for about 60-degrees at night and the daytime thermostat is set for 72-degrees. Sunlight will increase the GH temperature which will turn on the exhaust fan at a certain setpoint. An increase in the GH temperature will also decrease the humidity since humidity is 'relative' to temperature. Having it automatically controlled to turn the Aquafog and exhaust fan on will allow for some 'freedom' in owning and running a GH. Like Meltn, I also hose down the floor for added humidity. I also spray GH walls and even shelving area where pots are, just to bump up and emulate what a natural climate might be like. Every so often, I even use the "Mist" setting on my hose to simulate a tropical rain.....Some orchids love the occasional water drenching.

If you are unable to get a fogger or mister for your GH, consider having open vessels of water -- the greater the water-surface, the greater your chance of elevating your GH humidity.

Also, consider getting a fan to circulate your contained airspace in your GH. Without it, the environment will become stale very quickly and it will set you up for many problems.

Hope this helps.

wow do I have alot to learn. I am growing mostly tropicals and burgs, ginger ect. I guess my first step is to get a humidity meter. I have a misting system but the water is cold. the greenhouse is about 60 at night and 80 during the day. I just put a heater in. No fans, I do have pots with water plants in them. I keep most of the plants outside during the summer but I'm scared to leave them out. All the burgs I have I started from seed. Its very exciting when they grow. Thanks so much for the help.

Wow Lynn, sounds as if you have a great greenhouse set up. I would love to see pictures! My next major purchace will be a humidity controlled mist system. I will also have to come up with a way to warm the water in the winter.

Jltbaw, the cold water from the hose during winter is my biggest dilema. It is easy to use the garden hose for misting during summer, but, is not an option when the ground water is cold. I use quart size pump up hand misters as often as I can, but, they just put a dent in raising the humidity.

Vickie, I will definately share some Hoya cuttings with my Tenn. neighbor! They do not do alot of growing in the winter, but, they do not loose their leaves like Brugs and many other tropicals.

Thanks Mel I sure would love to try some Hoyas, let me know.
We still have not been able to complete the Poly up on the greenhouse with the weather but I have gotten my heater, fan ready to go and will probably mist by hand until I can swing a misting system. I also have a couple 5 gal. buckets that I am going to fill with water.
There is so much information on here and so many great people to help.
Thanks all and thank you Jltbaw for starting this tread..

Mel, I'll start a thread next week and post some of the pics that I took when we grew our greenhouse. LOL

I'm not sure of your own setup but have one suggestion: since you don't have a misting system yet, what about getting yourself a larger water container to hold more water. Put the water container inside the GH and fill it with water. The warmth in the GH will keep your contained water at the room temperature (and the water temp will even rise during warm, sunny days). Add a submersible pump, then attach your garden hose and nozzle. When you plug in your pump, the water will pump out and the pressure will be good enough to mist your GH. If you're REALLY inventive, make a rotating 'cradle' to hold the hose and nozzle which will free you to do small tasks while your GH is being automatically misted.

We recycle our condensate from our heat pump and dehumidifier in the summer. That water is contained in a 55-gallon drum with a submersible pump. The water is used to water our vegetable garden. This season, we're going to capture rainwater from our roof so that the rainwater can be used on special GH plants and if there is excess, the water will be used on some of the perennial beds.

I love knowing that we can recycle some of our water, and the more water available, the more I can freely water the gardens here. Maybe this idea can help.

You know, that is super idea, Lynn! Thanks a million and I will look forward to your "show and tell" post about your greenhouse!

Here's a pic of the little meter I bought at walmart.