Any serious home gardener will eventually need a greenhouse. I started by growing a few plants on my windowsill, and after a year or two, I decided I wanted more space for my container plants and hanging plants, and I couldn’t fit them all in my backyard in a slapshot fashion.
There are many manufacturers offering greenhouses for home use. A greenhouse kit is a more appropriate term. The greenhouse is shipped to you in one or two boxes, and you put it together yourself. I found the process to be pretty easy, as long as the instructions were clear.
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Greenhouses and Their Benefits
A greenhouse helps your plants to grow faster and stay healthy. The panels of a greenhouse are designed to keep out harmful UV rays and let just the right amount of sunlight in to keep them from wilting or growing slowly.
Maybe you are like me and want to start growing plants early in the spring or keep plants growing late in the fall. My greenhouse gives me a few extra weeks of since growing time in the spring and fall. I use automatic ventilation to expose the plants to the right temperature at all times. I use a heater in the fall if the weather gets too chilly.
I also like to overwinter plants that can’t survive for long when it gets frosty in my area. Overwintering means maintaining the minimum temperature a plant needs to survive. I need to heat my greenhouse for a short time to ensure delicate plants stay healthy. Most greenhouse kits don’t come with a heater, so I bought a small heater.
Some greenhouses help maintain plants in the winter without a heater, as long as the temperature inside the structure doesn’t need to be more than 30 degrees above the outside temperature for long. I would use an insulated greenhouse if I wanted to grow plants in the winter. Many greenhouse kits offer insulated panels.
A greenhouse lets me grow plants year-round. As long as the structure is insulated, sealed and has enough light transmission, I can grow flowers and vegetables even in the winter.
Greenhouses store heat from the sun to keep the interior warm enough for plants. In the summer, a greenhouse needs an evaporative cooler to keep it from getting too hot and harming plants.
Before buying a greenhouse, consider the following information. I went through a lot of trial and error (and money) because I didn’t plan before I bought my greenhouse. These tips will help you avoid any problems after buying and installing your greenhouse.
Building Permits for Greenhouses
Always check local ordinances for permit requirements. A simple lean-to or small shed-type greenhouse may not need a permit, but a large custom greenhouse may need one. In some locales, a self-installed greenhouse isn’t considered a permanent structure, so no permit is needed.
Choice of Material
Most DIY greenhouses have roof and side panels made of polycarbonate. This material gives gardeners the clarity of glass with added strength and resistance. Polycarbonate is also more fire-resistant than plastic panels.
Glass and fiberglass are other common greenhouse wall materials. Usually chosen for its beauty, glass is heavier than the other materials and has little insulating value. It breaks quickly, and a contractor needs to install it for best results. Fiberglass is translucent instead of transparent and comes in corrugated rolls instead of sheets. It retains heat well, but attracts dirt more easily than other materials.
Here are mini-reviews of the ten best greenhouse brands. I’ve had first-hand experience with a few of them, with varying results. The reviews are designed to help you make a better choice when it comes time to part with your hard-earned money.
Grandio Greenhouse Review
The popular Grandio Ascent greenhouse comes in five sizes – 8 by 8, eight by 12, eight by 16, eight by 20 and eight by 24. All these choices made it easier for me to choose the right greenhouse without worrying about running out of space. I needed a little more than what’s required for a beginner, so I’d select the eight by 12 greenhouse.)
The Ascent line comes with rain gutters on all models. The rain gutters help keep the 6mm twin wall polycarbonate panels in place. There’s an aluminum frame, and stainless steel nuts and bolts are included in the kit.
It’s no surprise Grandio Ascent greenhouses receive many excellent reviews from customers, as the brand offers superior construction and features. There’s a powder-coated steel base, an easy-latch door containing a double-ball catch and cross-roof truss bracing to hold high snow loads.
The Grandio Ascent line costs from $1199 to $3789 depending on the sizes and packages you choose. Premium packages include drip kit, trellis kit, automatic roof vent openers and plant hangers.
The smaller Grandio Element line features greenhouse kits sized six by 4, six by 8 and six by 12 for gardeners who need less space. Prices for these greenhouses range from $649 to $1929 for the most extensive premium package. All models include a base kit, 10mm twin wall polycarbonate panels, and rain gutters.
Grandio Elite Greenhouse, the third product line, have a barn shape and contain all the features of other Elite greenhouses. The door hangs from above to prevent jamming and the well-ventilated growing space, like other Grandio greenhouses, has excellent insulation and heat loss value. It is available in the same sizes as the Ascent line. Prices start at $1699 and go up to $4679 for the largest premium package.
All Grandio Greenhouse kits are shipped in two easy-to-carry boxes. Every piece is wrapped separately to prevent damage during shipment.
Unlike many personal greenhouses, Grandio kits come with thorough instructions. I know how frustrating it can be to deal with hard to understand or too-brief directions. I wish more manufacturers would take as much time writing decent step by step assembly tips.
Riga Greenhouse Review
Riga greenhouses have a reputation for durability, and experts consistently place Riga kits in the Top 5 of all greenhouses for home gardeners.
The Riga Onion series is named after the greenhouses’ onion shape. Constructed of an 8mm twin wall polycarbonate main body, these greenhouses also have a 10mm twin wall polycarbonate over the front and back panels to makes these areas even stronger. The Series consists of Riga models II, III, IIIs, IV, IVs, and V.
Riga Greenhouses range in size from seven to 17 feet wide and are either seven or nine feet wide. Rigas measure seven feet high most of the time but can go up slightly to seven feet six inches. All Riga Onion frames are made of durable aluminum. The features that I love include roof windows with automatic openers and a hinged rear window. I rank the Onion Series in my personal Top 5, so I wholeheartedly agree with greenhouse experts.
I’m not that tall, but a few of my gardening friends are, and they find they have to stoop
when using most Riga greenhouses. Due to the shape, the greenhouse slopes greatly from the top to the sides, making it harder for tall people to work on the outer edges of the interior. The middle of the greenhouse has enough space for anyone, regardless of height.
Riga Greenhouses are shipped via LTL Freight on a flatbed truck since the boxes are too heavy for common carriers. It will take a while to put the Riga together, regardless of size, and I had to borrow a few tools to put this greenhouse together.
Riga Greenhouses are pricier than most personal greenhouses but well worth the cost for most people. They’re sturdy, so I don’t need to worry about the weather report every day. I don’t need to cross my fingers when the weather gets too windy – the Riga will stay in place.
Riga’s Onion shaped greenhouses start at $3139 for smaller sizes and go up to around $16,498 for large, professional-sized models, according to the Riga website.
Brighton Greenhouse Review
The well-reviewed Brighton Greenhouse is available in two sizes, six by four and six by eight. Both sizes come with a steel base kit and a thicker than a normal aluminum frame. The 4mm twin wall polycarbonate panels offer insulation while letting just enough light enter the greenhouse. The non-yellowing panels are UV protected.
The opaque roof and walls diffuse bright rays that may harm plants. I like the look of the panels – they’re not too clear, as some brands, and less opaque than others. The roof vents help me control the temperature, and the rain gutters let me recycle water.
The Brighton provides extra headroom for better working conditions. This greenhouse lets me care for several hanging plants without crowding the space. The overall height and door height measure seven feet five inches and six feet five inches, respectively.
I was able to assemble this greenhouse in five hours with a friend helping me. The parts are shipped in two boxes, so I didn’t have to struggle with one massive package. When you open the boxes, the pieces may not look like much, but don’t worry. Once you put everything together, it will look and work fine.
You may need to use a spray lubricant to make the panels push together, and keep bolts loose to move pieces around during assembly. After you’ve put together the main sections, the greenhouse will be easy to move around. The Brighton is my first choice for small, portable greenhouse for beginners or folks with a minimum of plants.
Brighton offers a line of accessories, from shade nets to plant hangers, to make the most of its lightweight greenhouse. Premium packages cost a bit more and include a drip irrigation watering kit, trellis kit, and other extras.
The six by four greenhouse has a starting price of $449 and $609 for the premium package, according to the Brighton website, while the six by eight greenhouse has a starting price of $599, with the premium package costing $829.
ACF Greenhouse Review
ACF Greenhouses is a division of Aaron’s Creek Farms. The company, located in Buffalo Junction, Virginia, grows and sells commercial plants. ACF also sells and constructs greenhouses via their online store.
ACF sells several styles of warehouse kits and offers exacting customer service to help novice greenhouse gardeners.
The Cross Country line of custom greenhouses has standard, cottage, Cape Cod, and Lean-To versions. Standard Greenhouses feature curved or straight eaves, a 23-degree roof slope, and 6mm twin wall polycarbonate panels.
Seven basic configurations are available, from 8 feet wide and 7 feet high to 20 feet high and 10 inches high. I like that you can choose your preferred length. Each greenhouse offers you a choice of five different lengths, which varies on the height and width.
You can choose a greenhouse in white, green or brown and straight or curved eaves. Select an exhaust fan or automated roof vents. Stainless steel hardware is included to install the greenhouse. There are several options available, from roof cresting to a double door upgrade.
All custom Cross-Country Greenhouses have a storm door with tempered glass windows and a locking latch. I like the care and detail put into this brand, so I understand why it’s priced in the higher range. You get what you pay for, and these Cross-Country Greenhouses from ACF give you professional quality features.
Prices range from $4886 for the smallest model to $17, 301 for the largest, independent of options.
The Arctic Greenhouse is designed for colder climates and has 16mm five wall polycarbonate covering. Sizes start at 8 feet wide and 7 feet high to 20 feet wide by 10 feet high. Each size offers five or six choices for greenhouse length. Prices start at $7100 and go up to $45,469 for the largest version.
The Lean-To, the smallest Cross-Country Choice, offers 6 feet by 8 feet greenhouses up to 16 feet wide by 12 feet high. Prices start at $4597 and go up to $29, 281.
Learn more about other Cross-Country custom choices at the ACF website.
Palram Greenhouses Review
Palram makes many high-quality greenhouses for home and school use. There are sizes and styles for most home gardeners.
The Palram Harmony Greenhouse, a moderately-priced choice, has clear polycarbonate panels on the side and roof. It works fine on calm days and may falter on windy or snowy days. The Harmony offers five sizes – four, six, eight, ten and 14 feet. (The four-foot model is enough for my needs.)
All sizes have a hinged door, which opens outward, and a roof vent (or two, for the 14-foot model.) The Harmony Greenhouse has gutters built into both sides of the roof. The fitting at each end of the gutter lets you attach hoses with clips so you can aim excess rainwater in any direction you want.
The glazed polycarbonate roof and sides are clear as glass and virtually unbreakable. It gets quite windy where I live, so I worry about how stable the structure will be in a storm. Gardeners who deal with lots of inclement weather may want to look at greenhouses with sturdier panels and a more secure base.
Harmony Greenhouses costs go from $530 to $880 online. Retail prices may vary.
The Palram Nature Mythos Hobby Greenhouse also comes in five sizes – four, six, eight and ten feet wide, and 12 or 14 feet wide. All sizes have 4mm twin-wall polycarbonate panels which filter out up to 99% of UV rays. The Mythos has a rustproof aluminum frame, and from 24 to 84 square feet of space for plants and equipment, depending on the size greenhouse you buy.
The Mythos price ranges from $460 for the smallest model to $1200 for the largest one.
The Palram Snap Grow Hobby Greenhouse comes in seven sizes, from 6 by eight by 7 to 8 by 20 by 9. All Snap Grow Greenhouses have reinforced polycarbonate double walls, UV protection, and rust resistant aluminum frames. Workspace ranges from 53 to 164 square feet depending on size. Online prices range from $520 for the small greenhouse to $2000 for the largest model.
Juliana Greenhouses Review
Juliana Greenhouses have manufactured quality greenhouse kits since 1963. These greenhouses are constructed be 50% stronger than most other kits on the market.
All Juliana Greenhouse models (except minis) have standard gutters, and end caps direct rainwater and stops erosion on the outside of the greenhouse. Gutters also help the environment by letting me collect rainwater to water plants.
The 30-degree roof pitch allows for more headroom to prevent condensed water from dripping on plants. The roof windows let me ventilate the plants when needed.
Made from polycarbonate panels like most portable greenhouses, Juliana Greenhouses diffuse light so there won’t be any hotspots. Both roof and side panels have a UV coating.
The Juliana Premium Series Greenhouses have received many excellent reviews, and I can see why. These top of the line greenhouses have a durable aluminum frame and 10mm polycarbonate panels for more protection and better lighting for plants. The panels offer greater insulation against wind, snow and cold weather.
Juliana Premium Greenhouses are available in 9 by nine and 9 by 12 sizes. The peak of the available Juliana houses is eight feet, which offers lots of headroom when I’m standing in the middle of the greenhouse. The roof is sloped more than many barn-style greenhouses, so you may have to bend down to work on tables along the side wall.
You can buy an optional base kit and locking, hinged Dutch doors for better stability – and better looks.
The instructions were a bit hard to decipher. Ask a friend to help you put together a Juliana Premium (or any other Juliana greenhouse) if you have no experience setting up greenhouses or sheds. It’s easy to set up once you figure it out, but it can be frustrating at first.
Other product lines include the Gardener Greenhouses, geared for schools or home gardeners with modest needs, and Lean-To/Minis, which you can place against the exterior wall of your house or garage if you only have a few plants you need to work on or keep during the winter.
Juliana Greenhouses range in price from $220 to $1200, depending on the model, according to online sellers.
Easy Grow Greenhouses Review
Easy Grow greenhouses have high walls, barn-style rooftops, and an aluminum frame coated with green powder. The side walls are higher than many other greenhouses, giving me more headroom. The side and roof panels are 6mm twin-wall polycarbonate to keep the greenhouse sturdy during rain and high winds.
I was able to put this greenhouse together with minimal help. There’s no base included in the smaller kit, but larger ones have a base option. Kits come with gutters and four roof vents. There’s a double roller door which makes it easy to move in and out with large plants.
Barn-shaped Easy Grow Greenhouses come in several different sizes, including feet wide by 12 feet long and six feet wide by 10 feet long. Some models have a height of 8 feet 3 inches tall, enough to accommodate vines orchids and hanging baskets. I always found most other small greenhouse kits couldn’t fit all my hanging plants. Easy Grow greenhouses can do that.
Easy Grow also sells traditional greenhouses with the same 6mm twin-wall polycarbonate side and roof panels. They also have high side walls and a double roller door. Like the barn-style greenhouses, they feature green-powder coated aluminum frames.
I decided to add a few accessories to make the Easy Grow greenhouse even more functional. I bought a shade cloth to protect my plants from hot summers, and a heater for the winter months. I got both items from a separate supplier.
If you have lots of hanging plants as I do, need more room to move around or are pretty tall, the Easy Grow greenhouses will fit your needs. The barn shape is a little more pleasing to my eyes, but the traditional version has the same setup and comparable interior space.
Most dealers I found online indicate customers should “Call for Price.” The cost should be comparable to similar greenhouse models, from a few hundred dollars to $1000 for larger versions.
Shelter Logic Greenhouses Review
Shelter Logic offers tunnel and heavy duty greenhouses as well as smaller “Greenhouses in a Box.” I tried Shelter Logic’s Logic’s Grow-it Personal Greenhouse as a starter kit for my new flower garden. It had an all-steel frame with a waterproof, tarp-like cover. The triple-layered, translucent cover is heat-bonded and resistant to UV rays on the outside and inside.
For a small, portable greenhouse, the Shelter Logic Grow-It offers a lot of unique features. The Cross-Rail system ensures that the greenhouse retains its square shape. Shelter Logic’s trademarked “Ratchet Tite” tensioning keeps the cover firmly in place, and the Shelter Lock makes sure the greenhouse stays anchored. The frame has a baked-on Dupont powder coat finish.
Other Shelter Logic greenhouses include the High Tunnel Greenhouse, which offers more space for bigger plants. It has a galvanized steel frame, and it can be configured to the customer’s specifications. That’s perfect for me because my plant-growing needs change every year or two. There’s a polyethylene cover that protects plants and helps them to grow taller and faster and galvanized steel end frame panels.
Another greenhouse kit called the GrowIt Heavy Duty Greenhouse has the same features as the personal greenhouse in a larger version. It has an all-steel frame, a triple layer RipStop translucent cover with heat bonding, and two front and back zippered doors. Half-moon screen vents and roll-up side panels, located at the front and rear of the greenhouse, allow precise temperature and airflow control.
The High-Arch Greenhouse insulates and protects plants to extend the growing season. It has an alpine-style steel frame and 12 feet of overhead space for growing tall, healthy plants. Like the Heavy Duty Greenhouse, it has zippered doors in the front and rear.
Shelter Logic Greenhouses are perfect for people on a low-budget, like me, ranging in price from $150-$350.
Sunshine Greenhouses Review
A Sunshine Redwood Greenhouse is made of redwood, as the name implies. Redwood provides natural insulation and is insect and fungus-proof. The attractive wood frame combines with double-wall-polycarbonate panels for the sturdier outlay. The panels diffuse light for better plant growth and keep the greenhouse warm in the winter. The polycarbonate sheets block 98% of UV rays and won’t crack, even in intense weather.
The structures are wind-tested up to 85 degrees. They’re built on a 45-degree pitch to prevent snow load problems. (Snow holds up to 20 pounds per square foot.) All models have Dutch Doors, and the Mt. Rainier has accessible doors. Greenhouses have a vent at the top of the roof and lower back to maximize airflow.
I don’t need to worry about rotting at the base of the greenhouse. The recycled plastic base looks like wood, and I installed it directly in the ground. I didn’t have to add a foundation.
I like the automatic vent openers that adjust the temperature without batteries or electricity. There’s a hydraulic cylinder full of wax that expands and pushes the vents open when warmed. The vents close automatically, too.
Sunshine greenhouses come with printed instructions and an assembly video. The labels are paneled for easier installation. I used a tape measure, power drill and six-foot ladder for assembly, so getting up and running wasn’t complicated.
The tall sidewalls and roof peak give me more growing space for my cayenne peppers, spinach, and other veggies. The extra room captures hot air above plants and allows room for more hanging baskets.
Sunshine Greenhouses are built in Washington State, and come in three basic models – the Mt. Rainier (my favorite), Mt. Hood, and Lean-To. The company also sells greenhouse accessories. They offer redwood benches for each model. (Some models can fit up to four benches.)
Sunshine Greenhouses are in the higher-price tier, from $1275 to $3900 on sale depending on size.
One Stop Greenhouse Review
I knew quite a bit about Harbor Freight before I discovered One Stop Greenhouses. Harbor Freight is an online shop that sells tools, and they also have many retail stores throughout the U.S. One Stop Gardens sells a DIY greenhouse bearing the Harbor Freight name. This greenhouse is one of the least expensive on the market. Even though I’m on a budget, I wasn’t happy about buying this kit. I’d heard from friends that the One Stop is flimsy and even moderate winds or rain can knock it down or cause damage.
I live in an area that’s prone to high winds in the fall and winter, so I was concerned about the reports of delicate construction. The greenhouse has dimensions of 12 feet long by 10 feet wide and 10 feet high. It’s made of aluminum and has two sliding doors. The slide and roof panels are made of single-wall polycarbonate, which may work fine when winds are calm, but won’t withstand any inclement weather.
The metal foundation base is described by the manufacturer as extra durable. Despite this, reviews are mixed for this garden greenhouse, with many customers describing a flimsy structure that didn’t stand up to bad weather.
The assembly instructions included with the kit are vague. I enlisted a friend with DIY skills to help me since I lack greenhouse building experience. The kit has four roof vents to circulate air better and offer climate control. I like the fact that this kit is lightweight and easy to use, but its shoddy construction and design put it near the bottom of greenhouse choices.
To be fair, I’ve heard people say that using extra metal pins will keep the greenhouse from coming apart in bad weather. However, most gardeners will prefer to pay more for a slightly sturdier, all-inclusive kit.
Harbor Freight lists this greenhouse at $649.99 before shipping.
Now that I’ve shared information about some of the top greenhouse brands, you can see that most greenhouse kits have many things in common. Most notably some type of polycarbonate, either single or twin-wall. Some models have rain gutters and door, and vent styles vary.
Budget is a determining factor for most people, but other than that, how do you decide which greenhouse is right for you? Consider where you’re going to place the greenhouse on your property, and how that position will affect sunlight and accessibility.
Weather is also a primary concern. A region with heavy snow, wind, and rain may cause flimsier greenhouses to collapse. Areas with heavy rain cause drainage problems and result in standing water, which can attract mosquitoes. Install a drainage system for your greenhouse or place your greenhouse in a well-drained area.
Winds can blow over greenhouses in many regions. I’ve used fences as windbreaks – they break up the wind force. You can also use trees, shrubs, a shed or another structure
Windbreaks impede light, so try to place them where they’ll block a small amount of light.
Set up your greenhouse on a level, dry site. I placed mine in the flattest part of my backyard. Keep the greenhouse away from pools, swing sets, children’s play areas or barbecues and outdoor dining areas.
What About Frames?
Aluminum frames are used in most hobby greenhouses. They aren’t as strong as galvanized steel, which is used in professional greenhouses and larger custom home greenhouses. Galvanized steel is much heavier than aluminum and rusts from consistent high humidity. It also requires more hardware to mount a stiff covering to it.
Lightweight aluminum frames won’t rust or break down from humidity or UV rays. It lacks any maintenance requirements and can be powder-coated in a variety of colors.
Aluminum frames should be engineered to increase strength since aluminum is naturally not as strong as galvanized steel. The frame I have was advertised as engineered aluminum. Look for this type of frame if you want the long-lasting qualities of aluminum with more strength than untreated ones.
Custom Vs. Off the Rack
A custom greenhouse always costs more than a pre-made one. Buying a custom greenhouse is preferable if you can afford it. A greenhouse suited to your needs will require less tweaking and maintenance as the years pass.
One of the worst mistakes you can make is to buy a greenhouse that’s too small for your plants. I made that mistake. I assumed I wouldn’t want to add more plants to my greenhouse, or use hanging baskets. When I decided to increase the number of plants I cared for, my DIY greenhouse couldn’t handle it. I couldn’t add another piece to the greenhouse to expand it. (Most DIY greenhouse kits are non-expandable.)
I ended up buying a larger greenhouse with rain gutters and a base. Buy one size larger than what you think you’ll need, and you won’t be disappointed. You can also use extra space for storage or another purpose if you decide against adding more plants.