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rootdiggernc

Your Best Greenhouse Advice?

rootdiggernc
16 years ago

Way Cool, I'm finally getting a greenhouse! I have it but it still needs to be put up, which starts next Tuesday!

Since I'm totally new to this (having a greenhouse) I would really appreciate everyone's best tips and tricks, Do's and Don'ts, things to consider?

It's a 10x12 kit, polycarbonate, 4 roof vents, double doors, from Harbor Freight. It will have electric and water run to it and by spring at least one of those automatic vent openers. Haven't figured out what or how to do plant shelves, but need to go cheap for now at least. What things should I absolutely have for it right away? ...and what can wait for spring? Thanks!

D

Comments (23)

  • nonews
    16 years ago
    last modified: 9 years ago

    There is a Greenhouse & GArden Structure Forum. I bet they will give you all kinds of ideas. Congratulations. Nancy

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    Thanks Nancy, I have been reading over there, but I know the folks here and appreciate their savvyness and good sense when it comes to all things having to do with gardening, lol... :D

  • trianglejohn
    16 years ago
    last modified: 9 years ago

    The biggest problem with greenhouses is that they create a perfect environment for pests and diseases as well as plants. When they are new they are like a garden of eden with few problems. But after years of use they can be a pain dealing with all the chemicals and pesticides. It is virtually impossible to set them up in such a way as to avoid this - it is the nature of the beast. So instead, think of how can you set things up so that you can break things down and really clean it every 3-5 years (every year if you develop a pest problem). Is there space nearby to move all the plants out and scrub the walls? Does it sit up higher than the ground around it so that hosing and scrubbing washes the pests out and away from the greenhouse? Is it under a tree canopy? are there large branches that could fall and damage it?

    Another problem with them is that they really take a beating from mother nature. Sitting out there in the hot sun, wind and rain all the time can stress and age the plastic, metal, weather stripping, etc, and the humid growing conditions can do a number on hinges and any sliding/locking parts.

    Most of the people I know that have backyard greenhouses eventually let them sorta fall apart and then get busy and do a major overhaul every 10 years or so. Some people break things down every 5 years or so and fix everything at once. Others kinda give up and neglect the whole thing until they have to have it torn down and hauled away. Even the commercial growers I know that have large greenhouses always seem to have a few that are barely standing up - they can be a lot of work.

    If it were me doing this I would pay carefull attention to where you place it - or set it up in such a way that you can move it if you find that your first choice isn't the best location. I would build up a raised pad of pea gravel or something similar that drains really well. And I would pay close attention to how things drain out of the greenhouse so that I don't cause more problems out in the yard with chemical and pesticide residues leeching out into the garden. I would try to place it somewhere that is easy to get to in the cold of winter so that I can spend time in it when the weather outside isn't gardening friendly.

    Nowadays I enjoy my temporary hoop house, which is just a flimsy greenhouse erected only for the winter. But I wish I had more space so that I could sit it in and putter around with propagating instead of just storing plants in it.

  • karen__w z7 NC
    16 years ago
    last modified: 9 years ago

    D, I'm just in the planning stages myself so have no personal experience, but I think air circulation is important to address now rather than waiting until spring. It will help keep your temperatures uniform and should also help prevent some of those diseases John mentioned. Karen

  • Ralph Whisnant
    16 years ago
    last modified: 9 years ago

    Deb, I second John's recommendation to cover the floor with several inches of pea gravel. I added 4-inches. I also bought a couple of rolls of porous landscape fabric and laid it on top of the gravel. It really helps keep things neater because once "stuff" gets into the gravel, it is really hard to remove. I only add enough heat to prevent things from freezing and this really helps with insect control, but it makes it harder to keep alive some things like coleus.

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    I really appreciate everyone's suggestions. We've already moved it to a different location. I was afraid the 1st spot might have water issues and with it being 10ft+ at the peak of the roof I didn't think it would look right near the house. The new spot (up the hill) will make it more difficult to run electric and water, but it can be done. I'm going to create a nursery bed/potting area on one side of it and a raised salad bed on the other. Something evergreen (maybe gardenia) on the north side and some deciduous shrubs (not too big) on the south side. Small pond in one corner on the inside and someday a waterfall at the front of it running down the hill to another pond. Yeah, only took me 20 years to get this so not sure how long before we do phase 2, lol.

    I had wondered about keeping the gravel clean. I was thinking about using some of the green indoor/outdoor carpet that we have left over from the wedding, where we sat chairs. Thought it would help to insulate it in the winter, then remove it in the summer. I don't want to do a whole lot with it in the summer once I can move things out of there and if I do my potting outside that should keep the debris to a minimum as well. I saw one greenhouse that used the paver stones on the inside. Looked attractive and would be easier to keep clean (blow) but wasn't sure how it would work overtop of the gravel.

    Don wants to find someone to weld the supports for shelving in and then use hardware cloth (I think that's the name) because on one side I need a place to hang very large hanging epi pots and they'll need to be put under the shelves to protect them from the full sun. I'm thinking I want one 18 shelf about eye level for small pots of things and then about a 30 inch shelf a little above waste high, which is where the epies will hang from on that side. They're going to also rig something to hang baskets along the center. The other side will have a storage area and then the standard 2 or 3 (haven't decided) shelves along that side.

    Along the back of it I'm going to winter my tall tropical houseplants. It's going to be so nice to not have that jungle indoors in the winter!!

    It has 4 vents, doors that are 37 1/2 by 75 1/2, and I have a large size industrial fan that should take care of moving air. I really don't think I'll need to worry too much about cooling since most of what's in there will be moved out in the summer and the vents/door etc should handle the warmer winter/spring days.

    I really hope to not resort to 'chemical' pesticides, maybe that's wishfull thinking? I've been reading up about using 'antistress2000'... a lot of people are saying that it also works to discourage insects. Toads are plentiful in my yard and I hope some will migrate to the GH.

    Please feel free to tell me if any of these ideas are goofy. I really want to do this right!!

  • trianglejohn
    16 years ago
    last modified: 9 years ago

    I had some large tubs with waterlilies in them that I kept in my hoop house - these had frogs in them during the summer and they stayed with them during the winter but they never moved around much. I think they really need lots of light and heat to keep up the bug killin'.

    My epi's seem to like a cool down during the winter. Not sure what the temps should be or if they all need the same amount of chilling. But a lot of my large potted tropicals never bloomed on a regular schedule until I started this whole hoop house thing.

    I think a lot of the greenhouse folks use pea gravel because it is cheap to replace. So they keep it clean as best they can and then every so often they scoop it out and replace it. Weeds will grow in it over time, but Ralph's idea about using tough landscape fabric should work. I use multiple layers of landscape fabric and strips of indoor/outdoor carpeting on mine.

    There are pests (bugs and viruses) that come in on tropical plants that can turn a greenhouse upside down. You'll really want to avoid buying stuf from Florida during the fall or winter. You'll want plants to spend at least a season in the yard before you put them in the greenhouse (let mother nature battle the bugs first). You can also set up a system of de-bugging things once you find pests. In my opinion, it isn't worth the trouble. When I find a bad pest infestation I simply toss the plant, pot and all into a plastic bag, seal it tight, and throw it away. If it is a normal day to day pest I might consider composting the plant and sterilizing the pot. But nowadays I have a vast storage area of plastic pots and enough homemade potting soil that I don't need to be heroic about plant rescue. The more plants I toss, the more I get to buy.

  • karen__w z7 NC
    16 years ago
    last modified: 9 years ago

    How warm are you planning on keeping your greenhouse? I'd really like to be able to overwinter coleus and get some of the aroids out of the bathtub upstairs, so I was thinking 50-55 for a minimum at night. Then I start considering all my dad's orchids I want to raid and wonder if I'll need to push that up just a bit. I also like the idea of gravel flooring, as I plan to use my greenhouse year round and might plant some things permanently in the floor. I don't mind a little judicious roundup if something undesirable resists yanking out.

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    John said......"The more plants I toss, the more I get to buy."

    LOL, now that sounds like a plan!

    The only thing I want to buy right now is a fragrant oleander. I always said if I ever got a greenhouse that would be the first plant I'd buy!

    We're using the crushed granite. The pea gravel cost quite a bit more. From some of what I've been reading some suggest putting landscape fabric down and then hardware cloth (to keep rodents out) and then the gravel and pavers. Would the pavers do that much towards helping with winter temps? I don't think I can do the pavers this year, but if it would help with heating cost might be good to look into in the future.

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    Karen, I'm not real certain yet, but I think I'd need to keep it at least 55 probably 60 in order to keep some of the tropicals from going dormant. I know that some of the EE's go dormant at 55. Epi's can actually take a few hours of freezing, but probably not good for them. Coleus I'm not concerned about I can keep a few of them in glasses on a windowsill indoors and maybe move them to the greenhouse early March. That or keep them in a friend's greenhouse that keeps hers much warmer. I know I want to do some sort of insulating on the north side, but haven't decided how/what to do as economically as possible yet.

    Last year I kept banana's potted in an unheated/unattached building and only the outer leaves died back, the rice paper plant actually grew, but the EE's died back. All I had on them was a lightbulb down close. The brugs died back to the roots and the figs did fine. So, brugs will go to the GH while most of the rest can still go to the building. I'm not worried about keeping the brugs growing and blooming, just would like to keep some of the stem alive. I also won't be heart broke if the EE's go dormant. It's the monstera, selloum, stephanotis, jasmine and citrus type stuff that I would like to keep green.

  • tamelask
    16 years ago
    last modified: 9 years ago

    karen, i overwintered a bunch of orchids in my cool greenhouse (plastic covered porch) last winter and they did well. we kept the night temps to around 45, but i know it fell to next to freezing or a bit below a couple of nights (we have a min/max thermometer to keep track). it's strange but things that would normally be hurt by those temps weren't fazed. something about the lack of wind and/or frost i guess. by keeping it so cool we have virtually no pest problems except a few aphids towards spring. i did spray with oil spray before i put everything in. and i did loose virtually all the coleus, stroblianthus and alternatheras. but since they seemed to be the only casualties, i'll try them in the house again and keep it cool. easier on the power bill. it still warmed to 70 or 80 most days by around lunchtime. the birds and i ate lunch out there most of the winter. i made an effort to water heavily if i knew it was to be cold to keep the humidity and temps just a bit warmer. oh, i had a couple pots of nasties in there and they bloomed most of the winter. they just loved the cool but even temps.

    since ours is attached to the house and on a wood deck, we laid down those rubber puzzle mats you can get in lowe's/ h/d. they weren't cheap, but it looks nice, is easy to sweep/mop, and is easy on the back if you're standing for long. even with the cracks they are pretty waterproof. when i'd spill something, i'd push open one of the joints or mop up the water or it'd sit there. one of the things we considered to warm it up was solar heat. we don't get a whole lot of sun in there (eastern exposure, shaded in aft) and i don't think it would be too effective for us. but it could work for you. get on the list for charlie's greenhouse supplies and grower's supply- they both sell these thin black heavy duty bags for solar collection. plus all sorts of other supplemental things.

    for shelves we used the shelving you get for clothes. it works just ok- you'll be happier with hardware cloth i think. we hope eventually to be bale to do a sunporch or some other pro kit, but for now it'll remain cheap plastic and screen in the summer. we had critters in there to help with bugs, too. don't know that they actually did anything except entertain, but we gave them a safe place to overwinter.

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    Does anyone know what is a good height for shelves? I'm just 5'4", I know that the height shelving you work at can make a big difference in how it effects your back.
    The solar bags sound interesting will see if I can find more info on them.

  • tamelask
    16 years ago
    last modified: 9 years ago

    forgot to mention about the bags that you can lay them flat or hang them on a wall. they sell supports and everything.

    i don't think the height for shelves matters as much as the height of where you actively pot up stuff. for that, i'd just go with a comfortable height- if your kitchen counter is about right, measure it. if it feels too tall, subtract a few inches, too low, add a few. or find a surface in your home that feels just right standing or sitting, depending on which you prefer, and plan from there. i know i'm a little tall and i don't like to bend so i tend to like surfaces a bit higher that the average. it kills my back to work on even a few inches too short of a surface, but too tall wears out your arms, so you're right to want it correct.

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    I'm still trying to figure out temp settings. I understand that the lower the temps the less bugs and fewer heating dollars used. Just how low will the topicals tolerate it (monstera, selloum, stephanotis, jasmines and citrus type stuff)?

  • tamelask
    16 years ago
    last modified: 9 years ago

    stephanotis, citrus love it. i had my monstera in the house so i'm not sure. i'd think jasmines would be ok. selloum isn't ringing a bell so i must not have any- lol.

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    The selloum is Philodendron bipinnatifidum. I have a hardy one in the ground, but not sure about the houseplant.

    I do know that when monstera is still outside in the fall it starts looking pretty rough with the cooler nights. It's one of the 1st plants I bring in.

  • Jeanine Gurley
    16 years ago
    last modified: 9 years ago

    I have some very non'technical greenhouse advice:

    Include a comfortable place to sit in your greenhouse.
    I have found that if I have a comfy place to sit and enjoy the 'fruits of my labor' I spend more time in there. I have two small passive greenhouses. The one with a nice place to sit is also very organized and in good repair. The other just gets minimal attention.

    This is especially nice on a cold February day when I can go out and enjoy my plants.

  • karen__w z7 NC
    16 years ago
    last modified: 9 years ago

    D,
    I start bringing in my most tropical aroids when night time temps drop close to 50. Is that soon enough for the monstera?
    Karen

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    Gran, I've actually thought of that. My DH has been talking about what kind I want. Prolly just use a lawn chair for now. I love going to places like BB's in the winter to get a green fix, but now I'll be able to go out back to get my green on, lol.

    Karen, Yes, that should work. With it hitting in the low 50's now I prolly need to go ahead and bring it (monstera) on in. It really looks unhappy pretty fast once it dips below 55.

  • lakewhysc
    16 years ago
    last modified: 9 years ago

    Others have already mentioned this, but good air circulation is a key component of a more disease-free greenhouse environment. Not only does the air movement help circulate heat in winter or help cool in summer, it helps to lessen threats of fungas spread in most underpot and crevices, and breezes/wind is one natural deterrent for spider mites (along with getting undersides of leaves wet).

    This basic integrated pest management system--good air circulation along with proper watering and tossing out diseased plants (and not introducing plants that are already infested into the greenhouse) will greatly lessen your need for bad chemical solutions. At best, you can do a lot with simple horticultural oil and soap in a hand-held spray bottle to kill off the first signs of scale, mealy bugs, aphids. Also, have a bottle of rubbing alcohol present to clean your pruners, knives, etc between plants, and DO wash used pots in a 10% bleach bath and then air dry.

    Another key issue is collecting and then using plants that are appropriate for the conditions in your space. Many larger "professional" conservatories are poorly planted in that full-sun plants are given full-sun exposures only in the most direct rays of summer, and then due to a wall, or too thick of shadecloth or glass coatings, truly don't get enough light from Sept-March. This causes leggier growth, thinner leaves, and stresses the plant, leading to a more optimal condition for aphids, mealy bugs and scales to really flourish on the stressed plants.

    ALso, allowing beneficial insects inside your house at times is always nice, especially katydids, ladybugs, etc. Just remember that caterpillars will eat various plants.

    You also made concerns about avoiding a dormancy in tropical plants over the winter. Well, to save energy costs, and to have overall plant health on all but most ultra tropical plants, you MUST have a forced dormancy. There is no "winter" in the tropics and substropics, but the dormancy that tropicals ensure for their health is a DRY SEASON. Typically dry seasons occur when sunrays are weakest (this is in stark contrast to Mediterranean climate plants that need hot and dry in summer and then wet in winter).

    So, to answer others remarks, selloum can take down into the lower 30s no problem, provided they are acclimated to gradual cooling temps over the course of a few weeks. At the same time temps cool, you MUST also lessen the water these plant have so to avoid a cold soil along with wet soil condition.

    This is also the rule for palms. Palms essential shut down all root growth when soil temps go below 75 F. Lower than that, they just "sit". You may have a frond open in the winter, but it is very slow, and overwatering tropical plants in a cool environment will definitely lead to their demise.

    Also, lower your humidity in the winter somewhat, and do not allow leaves to get wet (when it's cool). As water evaporates from leaves, they are cooled. This is fine in late spring, summer and early fall, but having leaves cool off slowly when temps are cool and the sun is weak is a sure way to cause fungal rotting on all plant parts.

    I assume that the water that youll have in your greenhouse is right from the tap or well, and therefore (in the winter especially) will be "cool"? Tropicals should be watered with water that is temperature in range of 70-80 F ideally. This may be difficult for you in winter, but would be beneficial if you plan to have a warmer temp greenhouse through Dec-Feb.

    If you use gravels for the floor, you can preventatively spray/wash it with a solution of 10% bleach or 20% white vinegar to kill algal growths. Just do it with good ventilation as to not harm plants.

    Unless you have ultra-tropical plants in your collection, and by that I mean plants from lands that would never normally have night temps below 55 F even in the "winter" (dry) seasons, I would allow a dry season dormany. Again, this saves fuel costs, doesn't encourage plants to actively grow when sunlight is weakest and in many plants, a dry-season dormancy is the trigger needed for many plants to flower (or at least know to go dormant before they grow that spurt in spring to then flower and fruit). Palms also like it drier when sun is weak and temps cooler.

  • bmwsav
    16 years ago
    last modified: 9 years ago

    I bought the same greenhouse from Harbor Freight.
    In the instructions it did state that it should be built in an area protected from the wind. Much to my dismay, I ignored this advice and built it in an open area.
    The very first time we had 30 mph gusts of wind, at least 5 of the side panels, two top panels, and one of the sliding doors blew off and into my neighbors yards.
    I have since re-enforced all panels with self threading screws and braced the front door entryway with a 2x4 board. So far its held up to 30 mph winds, but I still have nightmares of that experience and worry that one day we'll get winds over 30 and my re-enforcements won't hold.
    Trust me when I say you'll need to build it in an area that has a wind block.
    As for shelving, I use concrete blocks stacked to hold plastic coated wire closet shelving racks that are relatively inexpensive at Lowe's home center. They have them in 12' lengths that you need.
    Email with any questions- bmwsav@hotmail.com
    Randall

  • rootdiggernc
    Original Author
    16 years ago
    last modified: 9 years ago

    Thanks for all the info. We're still working on it. I've read a lot on the greenhouse forum as we've worked on this and so we have done the screws and are now in the process of caulking. We also did the extra bracing and are going to order a solar pool cover. This thing leaks like mad and we're having a diffcult time holding any heat in at night. We do still need to finish the caulking, especially around the (4) vents and around the doors. Still trying to work out how to do the door area. I'd love to meet the engineer that designed this, grrr....!! We had one panel blow out, but that was before we got the screws in. It's pretty solid now, no thanks to the design/manufacturing.

  • dianne1957
    16 years ago
    last modified: 9 years ago

    I have never had a "Green House" But I have always had a "Sun Room". Many of my house plants are 30-40 years old and tropical. Many many years ago I bought a book by Jerry Baker titled "Plants are like People" Published in 1971. (Giving away my age here!) He has had many publications since then! Without using insectisides (spelling?) and sticking to Green Palmolive Dish Soap; per his advice 1 ounce liquid soap per ten gallon water. Periodically watering and spraying the house plants, every 3-4 months or so.... I have had years of healthy plants. I detest the use of insecticides (spelling?). We have always had pets and I do not know how the poison effects them..........So for me (now with aging eyes)...... I now put on the magnifier reading glasses to inspect the leaves and soil. If I see anything crawling around; out comes the soapy water! As a preventative. You never kill them all...but can keep them at bay.! I soap up all the house plants at least 2 times per year (haul them outside). When you group plants together you are bound to see an infection.
    Try to isolate a new plant from the rest until you can see that it is clean from insects or disease. I had a beautiful Hibiscus that I let freeze because I did not want the "Insect" problem to follow it into the house. Sometimes you have to choose! Good Luck with the Green House and enjoy every minute! The propagation of plants is a noble art!..........Dianne

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