To help your plants and seedlings thrive, the best small greenhouses make the most out of your available space, the size of your plant collection, and your budget. While all the picks on this list measure under 6 by 6 feet, you'll also find some that are specially designed for really small spaces. Beyond dimensions, though, you'll first want to consider which frame material and cover will meet your needs.
- Steel: It's one of the most popular materials because it's durable and affordable. Though steel will rust over time, frames that have been powder-coated will stand up to rust particularly well. Steel is a heavier material, so is sturdier than aluminum. Note: steel is not a great insulator, so you may need to add an additional heater inside for harsh winters.
- Aluminum: It's not as wallet-friendly, but structures made with aluminum are lightweight, rust-resistant, and long-lasting. The downside is it's not a great insulator, and because it's lighter, some frames can easily be knocked about (or over) in high winds.
- Wood: A wood shelter can offer a beautiful aesthetic that retains heat well. However, it's prone to decay, so be discerning about which kind you go with. Cedar costs more, but it's more weather-and insect-resistant. Fir, on the other hand, is less likely to warp or split as fast as cedar, but it's known to rot quicker.
- Polycarbonate: Less expensive and significantly easier to install than traditional glass, this transparent material is pliable and less likely to break or be damaged by strong winds. They're more costly but worth it if you plan to keep your greenhouse around for years to come.
- Polyethylene (PE) and polyvinyl (PVC): These plastic tarp-like coverings are affordable and easy to install. Due to their delicate nature, though, they will need additional securing, like ground stakes to keep them in place during high winds (and to keep insulation intact).
Finally, the size you go with should match your space and your planting habits, so you'll find a vast variety among the list of the best greenhouse kits on Amazon below.
1. This Sturdy Walk-In Greenhouse With A Steel Frame
- Dimensions: 56.5 x 56.5 x 76.5 inches (length x width x height)
What makes this walk-in greenhouse stand out from other, similar models is the reinforced cover that has an additional mesh layer sandwiched between two polyethylene (PE) ones providing additional insulation and protection from high winds. The greenhouse kit comes also comes with ground stakes for additional stability. The powder-coated steel frame can be assembled using just the included connectors and there are no additional tools required, though a few reviewers suggested using a rubber mallet to assure all the pieces interlock properly.
The structure comes with eight, removable mesh shelves that users recommend securing to the frame with cable ties. For air circulation, you can roll-up the double-zipper door or the two "windows" on either side of the house (and all three can be secured with ties).
One grower's praise: " I love this little green house. We had it well secured so no problems with it blowing away plus I have it so full. I use this with a small radiator heater and a grow light I turn on during low light days. It is keeping all my tropicals super happy through the winter and my seedlings are just thriving... The little window it has to provide ventilation on warmer days is great too. It lets in a perfect amount of light and was very easy to put together."
2. A Small Greenhouse That’s So Affordable
- Dimensions: 71 x 36 x 36 inches (length x width x height)
This small greenhouse is perfect for insulating raised garden beds so they can experience a longer growing season. The frame is made from a durable, powder-coated steel alloy, and can be assembled without any additional tools or hardware. The structure has a polyvinyl (PVC) cover with two roll-up vents, as well as a zippered entrance that can be left open for additional air circulation. Just note that it doesn't come with anchoring stakes, and several reviewers recommended getting some if you plan on leaving it up through the windier months. Inside the box, however, you'll find a set of 50 plastic plant markers to help you keep track of newly planted seedlings. If you need something to cover a bit more space, you can also get this model in a 95-inch-long version, too.
One grower's praise: "These little cold-frames are wonderful! My vegetable garden got a healthy head start during the off and on light snow this spring. They are easy to put together and to take apart for storage. When first assembling the mini-greenhouse, I would suggest letting the plastic get nice and warm in a sunny spot. This allows the plastic to better stretch over the frame. In addition, I used a few pieces of duct tape to keep the plastic attached to the frame."
3. A Cute Wooden Greenhouse That Looks Like A Curio Cabinet
- Dimensions: 30 x 22.5 x 43 inches (length x width x height)
For a lovely addition to your deck or patio, this small greenhouse looks like a vintage apothecary but provides excellent light and insulation for your plants. The wooden frame is made from Chinese fir and the cabinet has polycarbonate panels all around, including the roof. Inside, there are two shelves that can be removed if you're putting in taller plants. In addition to opening up the front doors, you can add a little airflow by opening up the roof panel. Though assembly is straightforward, you'll need to provide a screwdriver and screws yourself.
One grower's praise: "Great quality! We just had three days of rain and it looks like nothing happened! Very lightweight which makes it super easy to move around. I moved the bottom shelf up which resulted in three storage compartments. I was surprised how many plants in can hold! I love that the top opens for ventilation and the side screws allow you to adjust and secure the lid in place. This means that the lid can go from wide open to leaving just a crack. Great product! Ordering a few more for sure!"
4. A Vertical Greenhouse For Patios And Other Small Spaces
- Dimensions: 27 x 18 x 63 inches (length x width x height)
This vertical greenhouse will keep plants thriving, without taking up a lot of space. The powder-coated steel frame can be assembled without any tools or additional hardware and comes with four metal shelves that can be reconfigured to make room for taller plants. Several reviewers recommended fastening the shelves to the frame with cable ties to keep them extra-secure. The polyethylene (PE) cover has a double-zipper "door" that rolls up and is secured with ties, giving your plants ventilation and you the right amount of space to water and clean them.
One grower's praise: "I really like this mini greenhouse. I bought it to keep my cactus plants out of the rain. It was really easy to build (no tools need). I reinforced the poles with plastic zip ties for precautionary reasons because I have a lot of weight on each shelf. It is very sturdy... The plastic housing is strong, zips easy, works like a charm. During the fall I will bring it in and remove the plastic cover and use it as my winter plant shelf by a window."
5. This Investment-Worthy Walk-In Greenhouse With Polycarbonate Panels
- Dimensions: 72.8 x 49.6 x 48.8 inches (length x width x height)
Though it comes with a higher price tag and is a bit larger than the other picks, this stunning greenhouse, has lots of features that make it a dream for plant enthusiasts. To start with, there are clear, polycarbonate panels on all sides, as well as twin-wall polycarbonate roof panels, including a hinged window. The frame has a sturdy, galvanized steel base, and aluminum siding, that is durable and sturdy, though will require more assembly time than other greenhouses. According to reviewers, you'll want to put aside a day to give yourself enough time to build it properly.
Reviewers also recommend investing in the brand's anchoring kit, which will keep your structure steady through inclement weather. You'll need a drill, screwdriver, ladder, and a bolt tightener to assemble. Unlike most of the other picks, this is not portable, so it's especially important to choose your permanent building site on level ground. Also, keep in mind that there are no shelves included, which gives you lots of flexibility with the planning, but these adjustable shelves are a great option. If this model pictured is not the right size for your plant collection, the greenhouse comes in four other sizes and two other finishes.
One grower's praise: "We've had this greenhouse for a couple of years and the only thing we would change is to get a bigger one. We live in an area that can get very high winds, and we did brace it to the ground. It has held up very well and we grow off season tomatoes, carnivorous plants, basil and a couple others that don't do well with wind. The polycarbonate remains clear. It was neither easy nor hard to put together. The instructions were very good, but since it's a kit and everything is in pieces, getting it to fit together was a little fiddly. I particularly like the door design. I have recommended this model to family and friends."
6. This Solid Wood Raised Garden Bed & Greenhouse Combo
- Dimensions: 48 x 22 x 46 inches (with cover; length x width x height)
Another great gardening investment, this greenhouse is unique because it combines a raised bed and removable cover. The plant box is made from 100% solid fir wood, allowing it to stay stable for whatever you grow inside. Though the floorboard is conveniently removable for cleaning or draining, there's also a drain hole built-in (and you'll get a PE liner). Once the included steel frame is installed, the PE greenhouse cover can be attached via Velcro tabs. A dual zipper door makes it easy to vent one side or open the entire thing up for more access. All the hardware needed for assembly is included.
One grower's praise: "With winter upon us this item is perfect for a small garden. My wife loves growing things and missed the winter growing. We tried a makeshift greenhouse but that was a failure. When we stumbled onto this we figured that it was worth a try. Turned out to be just what she wanted. Size was right for her small winter garden and it is exactly like a larger greenhouse only smaller. Temperatures inside are going to be perfect for her use."
You May Also Like: A Gazebo-Style Walk-In Greenhouse With Tons Of Space
- Dimensions: 77 x 88 inches (width x height)
This larger, hexagon-shaped greenhouse has lots of room for plants and seedlings and plenty of space for a gardener to move around while taking care of their crop. As one reviewer wrote, "what I like most about this greenhouse is that I can walk inside of it, there is plenty of room and I am 6'2." The powder-coated steel frame and the six mesh shelves can be assembled with no tools, using only the provided connectors. As with other models, reviewers recommend using zip ties to sturdy the shelves. The double-layer polyethylene (PE) cover protects plants and can be secured with the ground stakes included with this greenhouse kit. For ventilation, you'll need to roll up the entrance panel and secure it with the ties at the top. This uniquely designed house is also available with a green cover, that will still let in plenty of light.
One grower's praise: "This has been a great purchase for us. We put about 30 plants inside this greenhouse as well as a 6-ft tree. We anchored it down really well and it has handled 30 and 40 mph guesting winds. We put a small radiator heater inside with the plants and they are flourishing."