This is my new GH. I sloped the dirt 3 inches front to back then put 2 layers of plastic down then the gravel. I have a vent fan to place in the top side part and a Dayton 240v heater to hang on the inside. I have two functional windows, one on each side and another 3 foot door on the back wall to keep all open in the summer time. I have been sealing all the seams. I have some extra windows to build a small Gh inside for seeds. Any advice would be great.
That's shaping up to one fine-looking GH. It sounds like you have everything well planed. What advice do you need now?
Ken
I don't know. This is my first greenhouse.
You might need more ventilation come warmer months and I strongly recommend it. The plan looks good for now but consider converting as many upper windows, opposite the exhaust fan, to awning. You would be hard pressed to have too much moving air in a GH at any time of year. Did I miss mention of circulating fans or are you relying on the heater? Buoyant, moving air helps prevent disease. My fans run 24/7 year around. Your GH has great potential for years of pleasure. Good for you that you re-purposed materials in such a creative way!
Yep, I agree on it all. I don't run my fans 24 hrs. though. I have two in each GH. They run approximately 12 hrs. in the spring/summer, and 6-8 hrs. in the fall/winter. I do have fans behind/beside my four electric heaters (two in each GH) that come on when the heaters come on. That usually occurs in the night-time hours but when we really get cold, they will cycle on/off 24/7. Thus, I may have four fans running at one time. Good air movement is extremely important in GH's.
Ken
I gave my opinion. Air does not stagnate in nature outside of swamps. In the scheme of GH costs, fans are inexpensive to run. Constantly circulating air is known to reduce GH disease issues.
Vince, if you plan to germinate and grow seedlings it would be especially helpfully to have moving air.
Thank you for the input. Im thinking of putting a ceiling fan in or a wall mounted fan in the top corner part to blow over things. Haven't decided which one yet. What about the humidity levels inside. Will the fan help worth humidity inside too.
I'm away and using a tablet to communicate. Will get back with you shortly. Consider that the air should smell fresh and you should feel a continual light breeze. I installed an overhead watering system on a timer but prefer to hand spray if I'm around. My humidity is maintained at 60-80%. Plants that need a dry rest are staged away from the water heads but have the high humidity.
hmmm plenty to think about. I have no fans. Not a huge issue unless the solar pool blanket is on (without it there are upper openings that continuallly cross vent
Gypsi, you really need at least a fan in your GH. That air movement will prevent a host of problems, from mold/mildew to insect infestation. Plants really need to dry out between waterings/mistings, otherwise they will be prone to develop root/crown rot. A simple box fan is cheap and uses little electricity.
Ken
It's probably most accurate to say that it depends on what you are growing in regard to greenhouse conditions. Many tropicals will be okay if you can keep them warm enough through the cold months and keep a rein on insects. Some folks use their gh's until warmer weather and then empty them out. But, if you intend to use a gh for year around growing and/or you are growing plants that struggle in average house conditions, then it is important to replicate a natural environment as much as possible. From the standpoint of the physical structure you Ideally need...
1) Heat that fluctuates between a proper daytime temperature and a ten degree drop at night.
2) Maintenance of humidity levels that are appropriate to both the plants and the season, e.g. most tropicals have seasonal temperature and humidity variations with winter being cooler and drier than summer.
3) A watering system in place that works for you and your plants. Keep in mind you may need breaks from the job. Inexpensive tubing with misters or mini sprinkler heads are ideal. The heads come as 360 or 180 degrees so you can direct the water. A timer for what days and length of watering can be easily attached. Even if every plant is not perfectly watered the humidity (see #3) will help you squeak through if you are away or not up to the job. My system is so simple the tubing is held in place with binder clips. I find these indispensable for all kinds of gh tasks.
4) Air movement from top to bottom or the reverse that best replicates an outdoor environment. Passive ventilation provided by cross ventilation that maintains temperature is not normally adequate though it might work with what you grow. I use a small Vornado under a protected shelf. It's been running 24/7 for five years. The air should smell fresh and buoyant. Evidence of watering, such as water on the glass or floor, should be gone within a few hours.
5) Proper shading when warmer weather arrives. This is a big one that gh'ers neglect because they are so worried about getting tender plants through winter. Next thing you know it's spring and sun is on the roof, not the south wall. If you grow plants with succulent leaves, be they Phalaenopsis or Cattleya orchids or Clivia, they will literally cook in an overly hot gh because of the high water content in the leaves. They look great all through winter and then they are gone in a few hours. Know when to put on shade cloth in your area and make sure to have it on your calendar. Don't delay because of rainy days. You may go out for the afternoon and find the sun came out. I speak from experience. Most people buy standard shade cloth, as I did for over twenty years but have long since switched to Aluminet. http://www.aluminetshadecloth.com/ It is wonderfully reflective so that more light comes in the gh but not the heat. I shared roll with a friend, not the more expensive custom grommeted. You may be able to find someone to go in with you if you need less than their smalles amount. On the hottest days my gh is 10 degrees, or more, cooler than the outside air. We are not called "Hotlanta" for 'nothin.
I hope this helps. The above information pertains to the physical environment and not the culture of plants. I'm certainly no gh expert and have a pretty makeshift gh. In fact, I fondly call it the "greenhut". But I have had many gh's including attached and unattached, metal and wood framed, automated and not and have friends with unbelievably extravagant Victorian conservatories. Man, a computer gives one license to be long winded, yes? :>)
well it is pretty muggy in there with the waterfalls but I'm not seeing any problems with fungus or bugs at the moment. My ventilation is excellent, windows on 3 sides, high medium and low and almost as wide as the walls, when it's warm. Only time I might need a fan would be when I have the solar pool blanket on to BLOCK the winter wind. I had almost no produce last winter, just barely managed to keep a few outdoor plants and 2 geraniums alive.
So far swiss chard and the one rooted tomato seem to be quite happy with the humidity. I have several fans, will see what I can do tomorrow, but humid air does hold heat better
I read this whole thread and just noticed that you're right down the street from me (sort of). I know that for some, keeping the humidity down in winter isn't a huge problem but "swamp" is the natural state of things around here. If our State Flower isn't mold, it should be. We put our first gh up in late October and the fan runs on low 24/7. It's sitting just in front of the heater and tilted straight up so it draws air from the floor upwards. Ours is a temporary structure with no automatic vents so we open it up to let the whole thing air out every chance we have which so far, has been most days. I guess that's going to change this week though.
With the solar pool cover and one small heater, the temp in there has stayed exactly where we want it. Ours is full of tender tropicals and succulents and they are thriving. I have to be very careful about watering though. Even with all of the ventilation and the fan, the soil (including orchid mix) in many of the pots will stay moist for at least a week or more. Some things I'm only watering about once a month and the cacti aren't being watered at all. Everything is growing and blooming like crazy.
It sounds to me that you have a good handle on how to heat, how to vent, and how to move air in your greenhouse. I do almost the exact things though I have two heaters and four fans in each greenhouse. It is just so important to have good air movement (and of course good heat. It is 28 F this AM, down 25 degrees from yesterday AM). In my humble opinion, the reason I don't have all the problems with mold and pests in my greenhouses that people constantly complain about, is my air movement.
Ken
Ken, I feel like we have a good hold on the situation excluding the uncontrollable and ever present humidity. Every time I water I expect to find nothing more than a seething mass of fungus in there the day after. I'm sorely tempted to buy a de-humidifier. We've been lucky not to have much significant cold so far this year. It's supposed to be in the low 20's this week which will be 'teens out here in the boonies where we are. Hopefully we have our propane difficulties worked out so that we can crank up the back-up heat.
There is not much we can do about our humidity here in the Deep South. Constantly moving the air minimizes this problem though.
Ken
I still haven't put a fan in mine, but I have enough air leaks that humidity doesn't get over 50% very often now that i turned off the "rainmaker" pump on the stock tank and went to an internal circulating pump with some glass lids 3/4 closed. Our air is so dry here due to drought most of the time, it is tough to keep humidity UP.
The humidity in my two greenhouses is elevated even higher because of the way I built my flooring. I laid down 4" of cypress mulch and then covered that with a permeable flooring fabric. Not only does the cypress retain a good bit of moisture, releasing it slowly inside the greenhouses, but the floor is really comfortable to walk and stand on.
Gypsi, I sure do envy you. I haven't felt truly dried out since I moved from Tennessee to this bog. Finally broke down this year and accepted rubber boots as "every day wear". I understand the math but my mind still says that if the humidity is 100%, it should be raining.
ya'll worked harder than I did. I have a mud floor, but it is also my "water the foundation point" as my slab has dropped 2 inches on one corner due to the drought, so as the mud softens (grey water from my kitchen) I am sinking bricks to walk on. Really complex engineering there..
I don't like humidity but the drought is ridiculous and is really tearing some houses up.
vincemoore88, My formula for seed starting is simple. I have a scrap piece of Corian that I put on the bench under my heat mat. Then I start the seeds in flats with clear domes with bottom heat. As I harden off the seedlings I vent the domes. I quite often direct sow into 6 pack or plug flats. My heat mat will accommodate 2 flats @ a time.
As others have stressed air movement is the key, especially in new seedlings to prevent damp off and rot. I really like the job you've done in reusing all those windows. For your area they should work quite well.
