Is your greenhouse full of plants? If so, the water in the pots will help to increase the humidity. If the greenhouse is empty, it will be hard to keep it high unless you have a water source.

You can check out my post The Greenhouse.....Its Alive, once you see how many plants I have, you will understand why I ask the question. I dont have humidity problems.

My floor is old bricks. They are on a clay base with sand swept into the cracks to stabilize them. Water drains into the ground and humidity is given up from the ground. My feet stay dry even when I water. If laid correctly, the floor is even and will last for many, many years. I can easily use my hand trucks to move plants which I can't do in heavy gravel or mulch. Mulch and gravel will build up like a bulldozer with gravel or mulch when I try to scoot big pots across the floor.

Thank you everyone for the suggestions. My greenhouse is filled with orchids (not as many as orchiddudes) and a few plants that can't take the cold outside. I take it that the flooring material under the benches won't really matter as long as I keep my plants well watered? The pavers in the walkway does help with the dolly to move plants in and out. I will try watering more often than once a week and see if that helps.
Orchiddude, how do you keep air circulation with that many plants?

I have the opposite problem of too much humidity in my Rion 8x16' GH. I had to add extra fans to move the air around better, water less and be careful about spills. I have a crushed packed limestone gravel floor.

If you don't have a lot of plants can you sit you container in large shallow pans of water.

I start seeds in Styrofoam cups with holes punched in the bottom of them and then sit tham in plastic trays like they sell at Lowe's garden shop and pour a inch of water in the pans it works really well

Thank you for the replies. Does too much air circulation reduce humidity? My greenhouse is 17 x 24 and has 2 20" circulating fans on the top to move air around. Should I turn off the fans now until I really need them during the summer? Is packed limestone good to keep moisture? Can I fill a couple of mortar tubs with water and place them in the pathways since I can's set my orchids in water? Thank you for your patience with all these questions while I try to figure this out.

Couldn't you just use a humidifier? They're pretty cheap, use little electricity and should be able to raise the humidity.

Don't turn off the fans or mold can become a real problem. I had to add several more fans once the GH was closed for the winter. Fans don't effect humidity. I'm not sure if the packed limestone is the cause of my high humidity. I did buy several used cheap humidifiers and found I didn't need them. I now have them in my plant-sun-room in the house. :)

What is your humidity at night? I can't imagine a g/h this time of the year not dripping with humidity, or at least mine does on dark dreary days and at night.

For orchids you need the fans circulating air 24/7.

Pea gravel or limestone gravel under your benches will definitely increase your humidity. I have limestone because it is the cheapest around here. When you water your plants, it soaks into the gravel and then into the soil. For two days we had super sunny weather and the g/h temps went to 90 with the humidity at 50%. By 7 last night, the humidity was 85% and the temp was 62. Today we have no sun and it is 75% right now - drip, drip, drip - with the heater running.

In the heat of summer, during the day my humidity will go under 30% if I don't thoroughly wet the gravel but at night, it returns to 80%.

Add gravel and then you may want ideas to reduce the humidity.

Brooke

Thank you everyone for your comments. I will put some pea gravel or whatever is cheaper here down and see what happens. I never thought I would have a problem keeping humidity up here on the gulfcoast. :)

Hey,
Yes, I do run a fan. I have a fan over my gas heater. Just a box fan. It runs day and night 24/7. Thats all I have. It keeps everything nice and happy.

DON'T use pea gravel where you are going to walk. You want crushed gravel that will pack down not pea gravel which rolls.

Trust me, pea gravel is horrible to walk on. I'm so sorry I used it.

Thank you for the responses. I will run my fan above my heater to help it distribute the heat in the greenhouse.
Buyorsell888, I have pavers for my walkways, but was thinking about putting the pea gravel under the benches. How is your greenhouse humidity with all that pea gravel in it?

I have pea gravel in my smaller HFGH and it doesn't so much for the humidity. It still stays around 30%. I have no idea why it's a more than twice that in the larger Rion.

Greenhouser,
thank you for that infomation/observation. This will really help me in deciding what to put under my benches.

I don't check the humidity so I don't know. I just know I almost twist an ankle every time I go in. Hate the stuff.

I just put up a new solexx oasis and was thinking about putting rubber mulch under the benches and pavers down the middle. Does anyone know about rubber mulch and whether that would be a good alternative to gravel?

Thinking of pouring concrete for my new greenhouse. I am new to gardening I really enjoy it and iam learning everyday. I was wondering if concrete is the way to or not. I live in louisiana so summers are truely hot. But winters are wet and temps do drop below 30. Any advice?