The Best Greenhouse Kits to Buy: Selecting Features You Need

Are you looking for the best greenhouse kits for your home garden, backyard, or business? Before you buy, there are some important things to consider so you don’t make a costly mistake!

Whether you want a polycarbonate greenhouse, a small DIY window frame structure, or a conventional round hoop house, I want to help you find the one that actually fits your space and your gardening style, so you will be happy with it for years to come! 

The Pinnacle of Gardening 

Many gardeners believe owning a greenhouse is the pinnacle of gardening. While greenhouses can be amazing tools, they are a gardening luxury, not a necessity for having a fantastic, fruitful garden. 

Not everyone can fit a greenhouse in their budget or on their property, but don’t despair! There are other great methods for gardening in the cold, such as winter sowing, building a DIY cold frame, or using frost blankets to protect plants.

If you have a greenhouse or are buying a greenhouse kit, I want to see you succeed! That’s why I've shared my expertise in greenhouse gardening and ways to heat a greenhouse, based on my years of experience operating a retail greenhouse. 

The Story of Scammy the Greenhouse

In December 2024, I needed a new greenhouse and found a guy on Facebook Marketplace selling greenhouse kits. I was on a budget, but he had a “brand new” kit he would sell me for $6,000, including installation.

We met, shook hands, and he asked for 50% down to start. This is standard, so I paid him $3,000, and he began construction the next week. When he finished, I went to see the greenhouse.

I was shocked by what I saw! The greenhouse kit was nothing more than a bunch of hodgepodge pieces. Some parts were not bolted together but instead taped… yes, taped together; other bolts were too long and poked through the already-used plastic, and the door (which was just a regular house door) wouldn’t shut. There were no corner braces, no sidewall braces, and the list goes on and on.

I tried to contact the guy, but it turns out that he took my money and ran. He never got the other 50% but my guess is he moved on with another fake alias and onto another victim.

I wasn’t surprised, or even sad, when Scammy the Greenhouse completely exploded in 60 mph winds. This is also why I didn’t salvage it or repair it.

Buying A Greenhouse Kit

Fast forward to today; I’ve done my homework and searched for the best greenhouse kits. Greenhouses have become something I’m passionate about! 

To help ensure that you don’t end up with Scammy the Greenhouse, the MIgardener store now partners with Bootstrap Farmer to carry a selection of top-quality greenhouse kits that we can stand behind! If you are looking for some of the highest quality greenhouse kits on the market today, check out their kits:

• Hobby Greenhouse kit

• DIY Gothic Greenhouse Kit 

• Gothic All-Metal Hoop House Kit

• All-Metal Round Hoop House Kit 

• DIY Greenhouse Kit: 10-Foot Wide Hoop House

• DIY Greenhouse Kit: 20-Foot Wide Hoop House

How to Choose the Best Greenhouse Kits For Your Needs

When you skim through greenhouses online, they all seem fairly similar at first. But the more you research and understand, the more you will realize there are vast differences and benefits for different regions, growing styles, applications, longevity, and more. 

There are pros and cons to every greenhouse style. What is best for you is based on where you live and your preferences. A relatively small change in cost might make a big difference in how a greenhouse performs for you. 

That’s why greenhouse features should be considered on a case-by-case basis. No one wants to spend more money than they need to, but neither do we want to be disappointed by our purchase or have it fail to withstand local weather conditions.

The main considerations when buying a kit or building a DIY greenhouse are:

• Greenhouse Style

• Snow Load

• Additional Structural Support

• Active & Passive Ventilation Options

• Single or Double Layer Poly Film

Styles of Greenhouses

The design style of a greenhouse is about more than just appearances. When you are shopping for greenhouses, you will come across 3 main styles: 

• Peaked Roof - Peaked roof greenhouses preform better than other styles in cold regions. A gothic-style greenhouse has a high peaked roof that curves down into steep, shorter sidewalls, while a gabled roof greenhouse has a conventional peaked roof that comes down to vertical sidewalls. 

• Hoop House - A hoop-house greenhouse has no flat edges on the roof or sidewalls; it is one continuous, rounded shape, like a semi-circle.

• Solid Wall Construction - The third style is a solid wall construction. This is typically seen with DIY greenhouses where glass, repurposed windows, or polycarbonate paneling is used to create a rigid structure. 

Any peaked roof has angled sides that face the sun, allowing more sunlight in and trapping that energy, so it bounces around instead of escaping back out. This style will save you money on your heat bill if you live in a colder climate.

Any greenhouse with a rounded or arched roof loses more heat because the energy swirls around the edges (instead of bouncing around inside), allowing it to escape through the thin sides. That makes this style better suited for growing in warmer climates.

Snow Load

You need to take into account how much snow you get in the winter! Any style with a peaked roof will have a higher snow load, so if you live in an area that regularly gets snow, go with a peaked roof design like this DIY Gothic Greenhouse Kit.

You may be surprised to learn that snow will not slide off a round hoop house easily, and that this roof style cannot support much weight. Flat-roofed greenhouses and round hoop house greenhouses are the worst choices for snowy locations. They will absolutely suffer under heavy snow loads, especially wet, sticky snow. 

Purlins: Additional Structural Support

Adding purlins to your build will increase its overall strength and rigidity. Ask yourself whether you need additional structural support to withstand heavy snow loads or high winds. 

Often, a greenhouse kit does not include purlins. Our supplier, Bootstrap Farmer, states on their website that most reputable manufacturers (including them) have purlin upgrade kits available as an add-on to any greenhouse/hoop house build. In my personal opinion, purlins are a must; it’s not worth the risk of going without! 

Purlins also add more functionality and permanence. They allow me to hang box fans, grow lights, or hanging baskets inside my greenhouse. 

Greenhouse Ventilation

Ventilation is a must in any greenhouse! The question is whether you will pay for a built-in ventilation system or choose alternative ventilation options. Many greenhouse kits offer options for fans, blowers, roll-up sidewalls, or vents.

Passive Ventilation

Every greenhouse should have some form of passive ventilation. Passive ventilation uses the power of nature (wind, thermal convection, etc.) to circulate air and maintain the greenhouse climate. Without it, your greenhouse can turn into a terrarium fast, and you’ll end up with mildew, mold, pests, and plant rot.

Having roll-up sides is invaluable for passive ventilation! You can also use vents, windows, or doors in the greenhouse's endwalls. Passive ventilation alone might be enough in a very small greenhouse, but I recommend installing some form of active ventilation in most greenhouses.

Active Greenhouse Ventilation

I opted for thermostat-controlled endwall louver vents and roll-up sidewalls for my passive ventilation, plus I added 4 box fans hanging from the purlins that I purchased at a local hardware store for active ventilation. Active ventilation uses mechanical devices, such as fans or blowers, to force air movement. 

Adding central endwall fans to my greenhouse kit was going to cost about an additional $1,000. I did not install the in-wall ventilation system in my retail greenhouse and have not regretted it. The total cost to add my four fans, including conduit and wiring, was about $180, saving me over $800 from the built-in option. 

I will say that my system takes longer to cool the greenhouse down. So the built-in ventilation system may be worth it for you, given its efficiency, especially if you live in an environment that heats up quickly.

Single or Double Layer Poly Film

The only time this is a concern is if you are opting for a greenhouse made with poly film over a frame rather than a solid wall construction. Then, you need to decide whether you need a single or double layer of poly film. 

Having a double layer of poly makes a greenhouse more efficient. In my greenhouse, servo fans blow air in between the two layers of poly, creating an air gap. That air gap acts as an insulating barrier, providing an additional 3° to 4°F of protection from the ambient temperature.

A double layer also reduces wear and tear on the outer poly layer, increasing its longevity. As the wind blows, the poly can chafe against the metal frame. A double layer of poly, inflated with an air gap, removes all that friction. 

It will cost more: there is the cost of the second poly film, the servo fans, and electricity, but in my opinion, it is well worth it!

I hope you learned something new and end up buying the best greenhouse kit for you, so you can Grow Bigger!