So, you want to grow year round? Or maybe extend your gardening season? Interested in growing plants that normally don’t survive in your neck of the woods? If the answer to any of these questions is “yes,” then a greenhouse might be for you.
Hobby Greenhouses
A backyard greenhouse kit can provide a stable, warm environment where plants can be grown all year. They can also be used to get a jump start on the growing season, where plants, like tomatoes and peppers, are planted early and later moved out to the garden. Whatever your reason for wanting a greenhouse, there are several types, styles and costs for almost anyone who wants to start gardening under glass — or polycarbonate, for that matter!
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Growing under cover requires a bit of specialized gear, but don’t worry. At Planet Natural we know what you need. From nursery pots and seed starting supplies to grow lights and plant supports, we have what you’re looking for!
Getting Started
The first thing to figure out when buying or building a greenhouse is how much growing space you will need. Keep in mind, that a greenhouse is a long-term investment. Your selection should be large enough to provide ample room for years to come. In many instances, greenhouse owners end up wanting more square footage than they originally thought. In addition, if you plan to grow vegetables, you’ll want maximum light and plenty of headroom, which is also good for hanging plants.
There are greenhouse kits available for just about any budget, and most (even if you aren’t handy with a hammer) can be built in less than a day. Below is a quick overview of the various styles available:
Attached. The big advantage with an attached or lean-to greenhouse is that you don’t need to build all four walls. Plus, you’ll have at least one sturdy, weight-bearing wall in place (usually your house or garage), so the three greenhouse sides can be built lighter. These structures are often less expensive than other greenhouse models and are good for growing herbs, seedlings, and some vegetables in places where space is at a premium. The disadvantage is, of course, that sunlight will be limited to only three sides.
Freestanding. Freestanding greenhouses, of course, stand alone, which lets you place them wherever you want on your property (as long as the site is level and receives plenty of light). While initially more expensive than an attached greenhouse, they provide a lower cost per plant, since so many more plants can be grown in them.
In most areas across the country, a freestanding greenhouse will allow you to start plants much earlier in the growing season (January or February) and then, at first sign of frost, you can bring your plants in again to extend the growing season through October or November. Here in Montana, a separate heating system is required for year-round operation. Learn more about heating a greenhouse below.
Freestanding greenhouses have the added advantage of being a sanctuary away from home. A relaxing place that you can go to get away for awhile. A place where no phones exist and you are surrounded only by the beauty of the flowers and plants that you are growing.
Glazing
Glazing is the covering around your greenhouse frame. It is responsible for letting sunlight and its warmth in while keeping the elements out. Glass is the best glazing material, but it is also the most expensive. Plastic sheeting works well and is inexpensive (see How to build a cheap and easy greenhouse), but will deteriorate quickly. Polycarbonate is less expensive than glass, is lightweight, and retains heat better than both glass or plastic. Additionally, polycarbonate can be used on flat or bent surfaces, transmits light well, and is extremely strong.
Site Selection
The closer to the house or garden your greenhouse is located, the more you are likely to use it. Also, consider access to electricity and water — both of which you’ll probably need.
Look for a level area with maximum exposure to the sun. If possible, find a location where the greenhouse will be getting at least 6 hours of direct sunlight per day during the winter. By orienting the greenhouse east to west, the largest side will get full southern sun exposure. If you don’t have an area with enough sun, grow lights can be added to compensate.
T5 GROW LIGHT
Hydrofarm’s best 4ft T5 Grow Light (bulbs included) is great for seedlings, cuttings, houseplants, flowers… and much more! Produces more than double the output as normal fluorescent fixtures. Ideal for shelves or over bench tops.
Deciduous trees can provide needed shade in the summer, but since they lose their leaves each fall, they allow for sunlight in the winter. Avoid selecting a greenhouse site (PDF) near coniferous trees or other objects that will cast a shadow during long winter months.
A greenhouse can be placed on almost any surface, but there should be adequate drainage. To create an ideal surface, lay a layer of landscape cloth over the area to be used — this will keep the weeds out, but allow for drainage — and cover the cloth with 3 inches of 1/4-inch gravel.
Accessories
In addition to the frame of the greenhouse, there are many accessories that can go inside. Depending on your commitment and budget, you can add shelving, automatic vents, a mist system, a heating system, a fan, a tool rack, a potting bench and the list goes on. Consider what you really need, what you’d like to have and what you have room for. At Planet Natural we can make your backyard planthouse as efficient and as easy-to-manage as can be.
Environmental Control
Heating. If you live in a cold climate you may need to insulate your greenhouse to help keep your plants toasty warm. While a lot of sun will come in during the day, an uninsulated greenhouse will cool off quickly at night. In this case, a heating system may be called for (see Greenhouse Heating Requirements).
A 220-volt circuit electric heater works well. Small gas or oil heaters designed to be installed through a masonry wall are also effective. There are also solar heaters designed specifically for greenhouses.
Radiant heat lamps hung over plants combined with soil heating cables under beds will keep most plants warm enough. Be sure the greenhouse is vented and that whatever heating system you have has an automatic shut-off.
Tip: Place rocks or barrels of water inside your greenhouse to capture the suns heat and keep plants warm during cool evenings (see Winter Growing: Heating Greenhouses).
#1 COOLING KIT
Beat the heat with our Sudden Shade Cooling Kit. Reduces daytime temperatures up to 15˚F while blocking the harmful infrared rays of the sun. Unique lock stitch construction can be cut with scissors to fit any area and won’t unravel. Perfect for vegetable gardens and greenhouses!
Shading. In warmer environments or when the sun is directly hitting the greenhouse, shading can keep plants from getting burned by reducing the amount of summer sunlight. Polypropylene shade cloth, roll-up screens of wood or aluminum, vinyl plastic shading, or paint-on materials can all be used to shade plants.
Ventilation. Plants can get too hot even during cold or cool weather, so good greenhouse ventilation is crucial. Vents can be hand cranked, but you’ll need to monitor temperatures closely. There are electric and temperature-sensitive hydraulic vents that automatically open and close.
Installing an oscillating fan will help keep air moving through the greenhouse and prevent many disease problems.
Pests. Keeping your greenhouse and gardening tools clean is the first step in avoiding pest problems. Check plants before bringing them into the greenhouse carefully to be sure they are bug and disease-free.
If cleanliness fails, immediately remove any plants with bugs or diseases. Spraying plant foliage with Safer® Insect Killing Soap will kill or deter many soft-bodied insect pests. Also, bring good bugs in — ladybugs, green lacewings, whitefly parasites and spider mite predators — to eat the bad bugs.
Recommended Products
Heat Mat (1-Flat)
Provides consistent warmth to improve germination success. Safe for indoor use.
1020 Seed Trays
Provides sturdy support and will NOT leak -- perfect for bottom-watering applications.
Plant Labels (50pk)
Works with a pencil so they can be erased and used over and over again.
Mist N' Spray
Features a wide mouth for easy filling/ cleaning and a convenient thumb lever.
Fiskars Snips
Comfortable Softgrip handles reduce stress and are non-slip for added safety.
Fabric Raised Beds
A framed fabric planter (BPA-free) that ensures healthy roots and superior plants.
Horti-Trellis
Secure vertically for climbing vines or horizontally with hydroponic setups.
Tomato Clips (100pk)
Use to improve air circulation and reduce disease in tall crops or vining vegetables.
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58 Responses to “Greenhouse Gardening 101”
You don’t say where you live, and that can make a BIG difference in how much success you would have growing in a greenhouse in winter. I live in Minnesota, where of course it gets really cold and days are short. I worked in a hydroponic greenhouse here, and we grew only greens, lettuces, kale, etc., in the winter. Spring through fall we grow tomatoes, basil, peppers and other greens, but they just won’t grow in the winter, there isn’t enough light. It also costs a lot of money to heat a greenhouse in winter, so do your homework before you make a decision. I should say that you can add supplemental lighting to a greenhouse in winter, but again it is very expensive.
Hi,
I will like to learn how to set up a greenhouse and grow tomatoes for a large population. I want to use this to alleviate hunger. Can you help me out?
Thanks
The author lives in montana. I also live in montana which is why I remember. Very helpful information.
Its a tricky business growing in the winter in a g/house, you have to keep it heated and it is really only good for starting seedlings off not producing veg or fruit as there’s not enough light this time of year, but from spring through to summer is the best time to grow the likes of tomatoes and cucumbers or whatever you want to grow. I wouldnt try to grow anything unless your going to heat the g/house every day and night and all you can put in is leeks or onions or some winter lettuce put thats just to start them off so there ready for spring time to go into the ground.
I would like to grow year round in my greenhouse. I live in Arizona and I don`t know how I could keep it cool. Without it costing a lot of money.
If anyone could help with any info I would really be grateful.
Thank you
Reanna
I also live in Arizona and wondered if you ever got any good info on how to keep it cool as well as humid?
Hi, I realize this is old and don’t know if you’ll get this but one suggestion would be to bury some galvanized metal duct with a screen for animals. Basically your making a vent, as the air sucks through the piping the ground will cool it. This doesn’t require a fan if you put a vent high up. the heat will naturally rise up and out while forcing air through the pipe to replace it. Just make sure there is some way to close the vent to keep heat in during winter.
also if it’s not to late you might look into a walipini style greenhouse,..
Try using an air conditioned place run by solar panels.
Move the vents to the highest point as well as the lowest point so that it can create a vacuum. Have as much open space inside as you can and consider a fan. If you lived in the NW I would be more help but unless I see it I can only give tips.
I live in salem OR how many hours do I have to leave grow light on during winter? I just want to grow tomatoes the plants are already established and are still fruiting at this time.
Chris, you still around ? Hobart Brickie here.
Hey I live in the Northwest and I am new to greenhouse growing and need help! It is still freezing at night but nice and sunny during the day. I have no idea what I’m doing, please help!
Greenhouse growing in Arizona? I would suggest digging the soil and setting it about 2 feet below ground level. If you find it too rocky to dig, I suggest a crank activate shade.
I live in southern Oregon and it gets hot here during the summers, triple digits. My greenhouse is set just north of an apple tree (I supposed any deciduous tree would work) so it is shaded in the spring and summer and not in the winter. I also have a sun umbrella that I can set on the west side to shade the greenhouse when needed. You could also install a fan. To answer the next persons question there are misters that are easy to set up to increase humidity.
Impressive write-up! Great guidance you have provided for the newbies on Greenhouse gardening. Thanks a lot for sharing your knowledge.
I am living in Guyanais it possible to do a greenhouse.
I live in North east Georgia and we have stick built a 12 X 16 greenhouse/chicken coop. Chickens have 4 X 8 inside coop with a 10 X 10 outside pin with shade. Trying to decide on heat to grow during winter. Leaning toward wall mounted L P gas heater. I have a thermostat fan & lots of windows that will tilt out. Would like some guidance. I want flowers & veggies. I’m getting 4 eggs a day from 4 RR 6 mos.old plus 4 more RR 4 mos old not yet laying. All suggestions welcome!
Live in Wyoming. Have had a greenhouse…greenhouses for many years. Can eat tomatoes thru thanksgiving…..
No light, or heat….by using polypropylene layered with bubble pak layers and sheets, comforters over them at times.
But broccoli and cauliflower, Brussels Sprouts go year after year if you use the side shoots in salads. Spinach can
Freeze. Lettuce does great as do onions. Can eat from greenhouse year round. We have a shade tree to west and
big double doors. In 90 degree plus we use misters and fans. There is a book about 4 season gardening in Maine
That helped us. The greenhouse is a lean-to against the south wall of the house and we open the windows and use
fans to pull the warm humid air thru the house in winter. In summer we open windows to our shaded north side of
The house and fans pushing cool air into the greenhouse…forms a flow that pulls cool air from the north thru the house. Very wonderful to sit out in flowers and veggies with snow on the ground and have morning coffee!
Hi – We just put up a Clima Pod hobby greenhouse for the winter. We want to keep a couple of different palms alive, along with a few elephant ears. Come early spring it will be fun to start seeds. But for now, will keeping the greenhouse at 40 degrees be ok? Thru Jan and Feb? I know they will go dormant but not sure if that’s too cold. Thanks!
Laura, you have to decide the inside design temperature based on which crops you need to grow in it.
First winter to attempt to grow a greenhouse garden. I live in south central Texas and sometimes we don’t get a killing frost until late November or early December. I want to know if there is a book on greenhouse gardening for this area that will tell me what lights and a watering system that I will need. I have two grow lights and have heat if it gets too cold. How long do I need to leave my grow lights on at night? Any help would be appreciated.
I would like to stay in touch, on how yours does. I am a truck driver coming home in Feb. and plan on finding some farm/pasture land. The problem is caliche and no water. I had the idea of a green house to cut my food cost and healthier food as well, though about a small chicken house and some cows and a couple goats. Don’t no where this adventures going to go. I think its going to be a lot of fun and work but will be worth it. Good luck!
Dyke Stewart good luck…enjoy. It will be challenging but worth every minute
You should be fine with just moving your dirt into your empty space and making sure that its getting all day sun.
Hi, I recently bought a greenhouse in Florida. I am not sure how I can use it. Will the heat kill my seeds. Went in it today and it was very hot inside. My greenhouse has a plastic green covering semi transparent I am not sure if sunlight is able to penetrate. Just took some bulbs out of there because they were starting to turn brown when they were nice and green when put in pots. I am confused what I can do with it. Any advice would be appreciated.
Tear it down….. if you have a buzz saw and can use a drill I can email you the cut sheet our company uses.
I would love to see your plans. I’m a newbie so all help is appreciated.
Currently we are working in a project that require calculating cooling load of a greenhouse made of polycarbonate. If u can send me the sheets through this email: ma.ba.owner@gmail.com, that will be great.
Hi Doreen. I have just purchased a greenhouse myself. I live in central FL, but am from south Jersey. I grew tired of the bugs, worms and squirrels here. I plan on running electric to it so I can put in two fans. It also has eight screened windows. This is my first greenhouse. I plan on covering the floor with a tarp and raising my plants off the floor so they can drain. I hope it works!
I bought a plastic type greenhouse from big lots. And the greenhouse ripped the first wind that came up. It is still ripping and breaking in the plastic parts. I don’t know whether to salvage or put it away for winter. I just was able to grow a few flowers and some of the shelves dumped off my newly planted seeds, also because of the wind again. Sincerely, a” green” green house adventurer, Connie
Remember the story of the 3 little piggies.
We have had high 90’s the past week, the pots in greenhouse very hot to touch. I put houseplants in them, leaves were burnt. What can I grow in my greenhouse flower wise in Northern, Ca. Santa Clara, Ca.
Hello! I live in Ontario Canada and have fallen in Love with gardening. It might sound odd, but I like annuals, and the colors they bring. I want to buy a greenhouse kit and start them off in the winter. Is this possible? I am not a pro and would like some advice. Now, what I can contribute is how to heat it, for free considering I have orange trees in my back yard (real ones, like you buy at the store) which I can pick year round. I was an Orange farmer in Israel, so I do know a bit. Every site I have looked at gives way too complicated or dangerous solutions. My trees are tarped with clear plastic and the heat source? SImple.. If someone can tell me advice on growing flowers, I will tell them how to heat a 12×60 ft greenhouse free in the winter to the point of it being well below zero outside and you can walk in shorts inside.
No Joke… Aharon
I don’t have much flower advice, but I’d love to know how you keep orange trees alive in Canada! I live in Wyoming, and have a floundering peach tree that never does very well… I’m sure it’s not staying warm enough in the winter, and 3 out of 4 years we get a late spring frost that kills off the blooms.
Not sure how to tell ya’ on flowers. My wife can grow the flowers and I have been perfecting the garden veggies. Got most down pretty well but still having trouble finding balance on tomatoes… plants grow big but not as much fruit as I would like or think. I have just recently purchased a greenhouse. I live in a very cold region in the winter time. I really need to know how to heat in the winter time. Is there some deal or trade we can make that I may have your secret for heating greenhouse.
I live in Northern California, the real one, not Sacramento as its central California. It gets down to negative degrees sometimes. Heating greenhouse, wood stove. Works for both houses. Circulating electronic temperature sensitive louvers help with over heating. Electric? Only for rich folks who are against getting up when too cold to stoke fire.
Can grow lettuce year round, as well as others. It’s growing gangbusters right now.
Northern California, the real north. Greenhouse, attached to well-house. Wood stove works great for heating and is free. Trees around for wood. Grow year round, anything. 2 grow lights for seedlings.
It’s a great hobby that pays off well. Growing squash, takes awhile. Need more information on vertical growing. Looking on internet.
I live in charleston SC and just assembled a green house. I want to protect my hanging plants over the winter period (normally mild). How do I use the greenhouse correctly; do I need to have buckets of water inside for humidity, a fan for circulation, etc. I am looking for something like managing a greenhouse for dummies. Any thoughts are welcome!
Good content ! Great guidance, you have provided for the newbies on Greenhouse gardening. Challenging yet fruitful once you know the techniques.
I live in north Ga. My husband built me a beautiful greenhouse and I don’t know much about how to use it or what I can grow. I’m mostly interested in growing flowers. Can you help me out? When should I start seeds for spring and summer flower? What temp should I use to over winter my summer flowers?
Thanks
Hi,
My first attempt at this, too. I scavenged some 2″ gas line for my ribs. Scavenged reinforced plastic sheeting, from a construction site. Scavenged storm door, for entrance. So far have about $30.00 in hardware, and 1/2″ plastic pipe. The pipe is for ribs, over my growing beds. I have been saving my milk jugs, filling them with water, and painting them flat black. Even on a cloudy day, I can pick up a little warmth. My hoop house is 14 X20. I keep planting stuff, and it is growing like crazy. Tomatoes, beets, kale spinach. My cauliflower and onions, haven’t appeared. I’m gonna try them again.
Now, if I can develop a liking to kale, I’ll be fine.
Live in Washington DC area, Have aloe plants and other Southwest plants that I have been bringing inside and keeping sun lamps on them during daytime all winter. Will they stay alive in a Gardman greenhouse & will I need supplemental heat all winter?
I have put up my first greenhouse. I live in Northern Michigan. It is now April and I am wondering if I should start some seeds in my greenhouse now and then transplant to the garden beds in May?? Last year, we planted PLANTS mostly, seeds for only a few vegetables. I like to harvest sooner rather than later. The greenhouses open at the end of the month, would it be worth it to start my own plants now?? PLEASE HELP
Hi Amanda: I live in Muskoka, Canada and we are in our 3rd season of early start greenhouse growing. I start my seeds indoors, under grow lights with a fan blowing on them. Once they get their third set of leaves, I set them in our greenhouse. They do well, as long as they have constant air circulation and I have a small space heater under the bench in case the temp drops at night. I lost almost 300 tomato plants because I didn’t use the space heater! I start my flower seeds 2nd week of April and plant 3rd week of May. Hope this helps. Best of luck, and happy growing!
I live in Wyoming & my Husband is building me a greenhouse out of a Conx, railroad car. Has but windows on the full south side from top to bottom only… Do we need window in the top in order for the greenhouse to work?
Either way has pluses and negatives. A solid roof can reduce summer temps by blocking some light while still catching most of that precious winter sunlight as it tends to be at a lower angle. How well does the railroad car hold heat and how hard is it to cool? Are you planning on using it year round or just to extend your season? What are you growing? Or rather what does it like ;)… Full sun, partial sun, partial shade, or shade. Are they getting enough sun and how happy are they? What temperature does is it usually rest at during the day, and during the night? Go inside by the back and see how much light is hitting you, are you in the shade? Do you or the plants hanging out there want to be if so. depending on the angle of the sun from your greenhouse, altitude and time of year you may want more light on top or you might be better to increase light from the east or west for morning and evening light but again it really depends on what your plants want for light. just make sure you can vent if it starts getting to warm because a greenhouse can easily turn into an oven for those poor little plants 😉 Hope something in here helps a little if you haven’t already solved your decided ;).
I live in Kenya. I will like to start greenhouse and plant tomatoes. Kindly assist me with ideas. Am just new in the business. My salary can’t sustain me. I need to start this business.
Regards, Vinic Ombaso
Hi Vinic. I don’t really know if I can be helpful or not but I can try. You don’t really mention what kind of greenhouse you were thinking or needing. Sadly I really don’t know much about Kenya either. From my understanding High’s are around 85°F? If so you probably won’t need a Walipini but would be fine with a fully above ground greenhouse.
You mention not getting enough to get by so I’m guessing your looking for something cheap, maybe to extend your grow season a bit. There are a couple options, you can go with your typical metal hoop greenhouses with plastic sheeting, or make something cheap and temporary using pvc. The advantage there being that you can be uncovered it once it starts getting warm enough. How long is your grow season over there? The plastic is fairly cheap you just have to come up with a frame, that won’t rip it lol. Using the plastic you ideally want 2 lays with air in between to help with insulation. 2 warnings if you use a fan to pump air between the sheets from inside the greenhouse it will suck up a lot of humidity and could get mold growing between them, if you pump air from the outside then your pumping in cold air between the sheets possibly requiring more heating if it’s cold out. I’ve seen both work and have seen others that didn’t pump air between them but you want the plastic tight or wind will be more likely to tear the plastic.
Ideally I’d recommend a greenhouse made with lumber and polycarbonate sheeting. Automatic vents high up for cooling, Burred metal pipe or duct coming in from outside (3 feet underground probably 6in diameter). The ground cools the metal which in turn cools the air as it brings it in from outside, As the hot air rushes out through the vents it sucks cold air from the pipe no fan should be necessary this way. Now this could be expensive and something like it might be a long term goal.
There are lots of video’s out there, I’d suggest going to youtube and seeing what various people have found to work. Might help to find some ideas that work well with the local materials But there are lots of options out there, Wish I could be more helpful. and if there’s anything more specific you want help with or just to talk about I’d love to be able to help. Hope this was useful in some way….
I’m thinking of starting a greenhouse. I already have a small raised bed garden that is covered with fencing. So the frame is there, and I was thinking I would just cover that with the greenhouse plastic. I would only be using it to start things early, here is just the starting of summers, I live in India. Would I still need a heater or any of the other equipment? I’m an extreme beginner to the gardening world, but I really love it, and I would really appreciate the advice
Very helpful site – thank you! I live in Roseville, California (zone 9B – just north of Sacramento). In my back yard I grow tropicals in very large, heavy pots (and very difficult to move). These include hibiscus, plumeria and mandeville plants. Although our winters are mild, and we don’t have extended freezes, it gets cold enough that each of these plants dies completely during the winter. They need to be replaced each year – and they’re not cheap. This year I am thinking of using PVC pipes and joiners, along with the appropriate plastic sheeting, to build individual “pot sized” greenhouses that I can set over each individual pot and plant for the winter. An average one, for example, might be a vertical structure of about four feet tall, perhaps three feet wide. My hope is that the large pots full of dirt will absorb enough heat during the winter day to keep the plant from freezing during the night. I’m not planning any additional heating. Do you think this has a shot at working? I don’t see any “small” greenhouses during my internet searches, and am wondering if there’s a reason. I like this idea because I can disassemble the units every spring and store them for re-use. Thoughts? And if it’s a decent idea, should I cut ventilation holes in the plastic? Or would that defeat the purpose? Any help or thoughts would be much appreciated. Thanks! Pete
I’m from upstate SC and would like to have make a greenhouse in order to have veggies and maybe some berries…can I grow during winter months? Will it get too cold? Brand new at this so forgive me lol
Hi
Please I would like to know how to grow apples and berries in a greenhouse?
Please help! I have just started with our 6 x 8 greenhouse. Apparently, we require a small oscillating fan, and lighting… could anyone help with lighting suggestions? It appears 6500K is preferred for lighting. Any suggestions would be ever so helpful! Thanks in advance!
Yvonne
Hi Yvonne –
A small oscillating fan will increase airflow to prevent plant diseases and strengthen seedling stems. As for lighting, I recommend T5 Fluorescent Grow Lights. They produce more than double the light output as normal fluorescent fixtures and are ideal for shelves or over bench tops. Here’s a link:
https://www.planetnatural.com/product/t5-grow-light/.
Hope it helps!
I live in southern Indiana and have purchased a polycarbonate green house. Are heat pads needed to make seeds germinate.
I have an LP heater. On cool nights what temperature should I maintain in my greenhouse?
Hi –
I have a big greenhouse 14 x 12 and it has automatic vents. How do you stop windows opening up in winter? I am just scared of the wind catching them.