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greenhouser

Other GHs - what is your humidity at?

greenhouser
16 years ago

What is the humidity in your GHs and are you venting them in cold weather? If so how? And how are you preventing a serious drop in temperature? I'm having a furry black mold starting to attack the plants. Several young tomatoes and now two flower boxes of begonias had to be removed. I also saw a white coating on an old monkey flower plant so dumped that outside also. I added another fan several days ago but that's not helping.

Comments (20)

  • orchiddude
    16 years ago

    I hope about 80 to 90 percent.I am not home to look right now. The higher the humidity, the more heat the air will hold, the more heat, the warmer the plants are. Plus it feels so good at 55 degrees.

  • wetfeet101b
    16 years ago

    I have the opposite issue during the winter.

    My climate gets really dry in winter so I actually need to add moisture into the GH during the winter time. I cant water the plants directly so I just water down the floor and repeat after a few days when necessary.
    During the day it could drop to the low 30%. At night it holds around 50%.
    In the rare cases of winter rain, the humidity jumps a bit but it does not happen regularly enough to be a reliable source of humidity.

    Humidity gets high in summer, but at that time venting the GH is not an issue as the outside air temperature is acceptable.

  • greenhouser
    Original Author
    16 years ago

    wetfeet101b

    That's about like my smaller HFGH. I would wet everything down as needed. But this Rion is holding onto the moisture, dampness, humidity.... whatever to the point some plants are molding out. I'm sure glad all my favorite cacti and succulents are here in the house with me. It feels like a rain forest out there. Today the sun came out for awhile so the GH went up to 70F and the humidity dropped to 60%. I had one door open for some fresh air until the temps dropped a few degrees. I didn't find any new mold/mildew victims. I just dug another fan out of storage and will put it out there as soon as my coffee break is over.

  • greenhouser
    Original Author
    16 years ago

    orchiddude

    My orchids are going crazy out there. :) A rescue phal is throwing up two spikes, others have one. All but one rescue den is also spiking and the oncidium is about to bloom. Nights I have a minimum of 59F, days can go in to the mid 80s because the vents open and let the excess heat escape. I'll bring them in when the flowers start to open so we can injoy them in the sunroom.

    The poinsettias got so nice I brought them all in for the holidays.

  • orchiddude
    16 years ago

    greenhouser...keep watching my post as I will be showing you the cymbidiums as they bloom. I have one right now that is so cool looking. Tons of buds and stems growing. Its the most wonderful place in the world. People that dont have greenhouses, dont realize what they are missing. Orchids love the greenhouse temps this time of the year.
    Rob

  • greenhouser
    Original Author
    16 years ago

    Thanks, I will watch for the pics. I don't have any cymbidiums. I haven't seen any of them in the stores here.

  • ohiojay
    16 years ago

    Mine is set for a minimum of 70% right now but with the greenhouse closed up it hovers closer to 90+ a lot. I have to keep the windows cracked a bit because of the heaters so there is some air exchange. Other than that, no venting unless the sun would shine a bunch during the day and cause the temps to go up enough to cause the automatic window to open.

  • greenhouser
    Original Author
    16 years ago

    ohiojay

    What do you have set for 70%? A humidifier? I removed the one I had in the Rion because it wasn't needed. It's now chugging away in my sunroom. :) I just checked the humidity about 15 minutes ago out there and it was at 78%.

  • sandy0225
    16 years ago

    Watch your watering, especially if your plants are really crowded. You might have to pull some cycles to sweat some of that extra humidity out. Heat, then vent, then heat, then vent. If your plants can take that low of temps, heat it, or use the sun to heat it to around 65-70, then vent it down to around 50, and repeat to pull that moisture out.

  • greenhouser
    Original Author
    16 years ago

    Sandy

    I've cut back on watering and moved some of the plants back into the smaller, cooler HFGH. I added more fans to move the air.

    Heating and venting like that isn't possible, both because we're not always here during the day and because on a limited income we can't afford to heat the great outdoors.

    The heat shuts off at 62F and the vents open at 70F so on sunny days there is venting.

  • jbest123
    16 years ago

    Greenhouser, maybe someone could lend you a "wet bulb" thermometer or check eBay. You can use it to check the actual humidity compared to the indicated humidity. Some of the equipment sold to check relative humidity is pure junk.

    John

    Here is a link that might be useful: Wet Bulb Thermometer

  • orchiddude
    16 years ago

    An easy thing to do is just open the door on a good cool day. The outside air is drier and will help dry out the greenhouse.

  • greenhouser
    Original Author
    16 years ago

    jbest123

    I don't understand the difference. If it's less or more with a wet-bulb reading, it would still have the same effect on the plants and I can't do a whole lot about it apparently. We just can't afford to have vents open and the heaters running. The sweat is running down the GH walls and mold grows on every leaf that falls. I have impatience seedlings all over the floor. It's not quite as bad with the extra fans these past few days and I try not to spill water. The Rion was at 79% humidity and the HFGH at 35%. I was able to leave the doors open on both of them today while the sun was out.

    PS I used use a web-bulb that came with an incubator I had years ago.

  • greenhouser
    Original Author
    16 years ago

    orchiddude

    That's what I've been doing. As long as the sun is out the vents open, and if I'm here I crack the door for better air circulation. The humidity goes right back up though when the vents and door are closed. Odd I haven't had this problem with the smaller HFGH.

  • jbest123
    16 years ago

    I have noticed the same differences in the humidity in the HF and Rion. And up here in zone 5 the humidity runs at about 60% in the Rion. The Rion is more air tight and gets warmer through the day and probably evaporates more moisture which condenses when everything cools at night. A quick fix would be to run a dehumidifier this winter and consider putting down a vapor barrier under your flooring material this summer.

    John

  • greenhouser
    Original Author
    16 years ago

    jbest123

    They're things to consider but with each of these things such as fans I'm losing more and more space for plants. There really isn't any room for a humidifier large enough to pull down the humidity in a GH that size. I wish the Rion had a higher roof. I could then hang stuff and not lose all the floor space.

    As for digging up the packed gravel floor.... that would cost a small fortune even if we could find someone to do it.

  • orchiddude
    16 years ago

    I would stop all watering unless the plants are growing. Open the doors and windows, vents etc..., let it dry out. In the small space watering the plants is what causes it and you will have that problem until spring. I would just keep everything on the drier side and see what happens.
    You could spray a fungicide on the plants to stop any foreign growth of stuff.

  • ohiojay
    16 years ago

    Greenhouser,
    I have a fogging system for my humidity. However, it is unneeded during winter. The heaters put off enough moisture to keep the humidity high enough for me. It has been averaging around 85% lately. My deep tropicals love it.

  • greenhouser
    Original Author
    16 years ago

    orchiddude

    I've cut back on watering and the other day crept all around and reached under the tables and taller plants to pick up as many dropped leaves and flowers as possible. I sprayed the toms and peppers again with Neem oil and the floor with Lysol. I moved those that dislike excessive humidity to the smaller HFGH after picking off the moldy leaves. I'm going to see if I can find one more smaller fan the next time I'm in town. The extra fans seem to have helped. I haven't seen any new "fur" growing anywhere. :)

  • greenhouser
    Original Author
    16 years ago

    ohiojay z6

    Some of my plants love the high humidity also, but some were being attacked with a gray furry mold and some tomatoes died. It was spreading to some begonias. There were some dead air spaces. Several fans took care of that.