Glasshouses, conservatories, nurseries… there are many different terms used to refer to greenhouses. They serve an equally wide range of purposes, too. Whether you’re looking for the perfect environment in which to start out seedling plants, or somewhere that you can maintain the optimal temperature for your succulents throughout the winter, or even something that can house your exotics and protect them from the harshness of weather fluctuations, most come right back to the good, old-fashioned greenhouse.
But what do you need to know about greenhouses, and once you’ve learned those things, what type do you need to buy? Is there a benefit to the more-expensive types over the cheap ones? There’s a whole lot to learn, so let’s get into it!
Our Top Picks At Amazon:
- Best Small Greenhouse: Gardman R687 4-Tier Mini Greenhouse
- Best Portable Greenhouse: Quictent Portable Cloche
- Best Large Greenhouse: MELLCOM 26’x10′ Greenhouse Tunnel
- Best Heavy-Duty Greenhouse: Palram Snap & Grow
Other Good Choices From Amazon:
What To Look For In Your Greenhouse
While you may be looking at the wide range of greenhouses out there, eyes crossing at all of the variety, there’s some basic aspects that you need to take into consideration. Depending on what you are using your greenhouse for, these aspects may be of varying importance to you, so read on to learn more.
The bare bones framework for your greenhouse can be the difference between something you have to keep replacing and something that you buy just once.
While most cheap greenhouses are formed with lightweight aluminum tubes, which will hold up just fine for a season or two (and sometimes longer), there are more expensive ones made of wood or powder-coated steel, and I highly recommend those. The only time that aluminum is suitable for a greenhouse is when it is meant to hold solid panels rather than tubes, and is built much thicker and heavier than anticipated.
While there are homemade versions that use PVC to good effect, the commercial options typically don’t.
Hardcover or Softcover?
If you’re on a quest for the best greenhouse material, you may find it difficult. There is no single best material for greenhouse use. The question of whether you want a hard-paneled greenhouse or one with a soft, lightweight cover really depends on what your environment is like and how often you’re going to use it.
If you are using it to provide light while maintaining the temperature inside, keeping it warmer than outdoors or using fans to keep it cooler, or in some rarer circumstances using swamp coolers to raise the humidity inside, you probably want a hard panel option. Most of the hard panels now are made from high-quality polycarbonate sheeting, which offers wind resistance, snow and ice resistance, and keeps the temperature inside stable.
If you are looking for something a bit lighter in weight, or something portable, you may want to opt for a flexible polyethylene cover material or a PVC fabric. There are rip-stop vinyl options out there as well which can provide you a good cover to keep the ambient warmth inside higher than the outside air. These options are good for most basic home gardeners who are just looking to keep growing during the colder months of the year, but they won’t hold up to heavy snow weight as well, and need to be replaced more often.
While we’re on the topic of snow weight, the sturdiness of the construction is key. If you live in an environment where you get heavy snows, a flexible cover is probably not your best bet, as it can tear, puncture, or sag and warp over time. In addition, if you’re in a windy area, those flexible covers can act like a sail and cause your greenhouse to go flying if it’s not staked down.
It helps if the design of your greenhouse is built with strength in mind. If, for example, you pair a soft cover with a frame that precisely fits inside that cover and stretches into place, the entire structure is a bit more stable. Weighing it down with plants will only help that to stand up to a bit of abuse. But that will only do so much, so consider your weather conditions before purchasing.
Do you have a very small back yard, or do you have a couple of acres to play with? This makes a huge difference in your greenhouse needs. If you’ve got a small yard, and all you’re doing is propagating some plants for transplant elsewhere in your yard, you might not need anything big. But if you’ve got an acre or two of land, a larger greenhouse gives you the ability to start seeds and have a nursery for your young plants until it’s transplant season.
In addition, some types of larger greenhouse can be used to provide both shade cover in the summer and warmth in the winter. Depending on your weather patterns, you may be able to grow in these year-round. And if you grow hydroponically, these can offer you the light you need while keeping random insects or plant matter from landing in your outdoor tanks, thereby protecting your pumps.
While a greenhouse is fantastic at trapping the heat from the sun, it can also rapidly turn into an oven due to its clear sides amplifying the sun’s warmth. In hotter environments, this is especially problematic. You need adequate ventilation to let excess heat escape.
You also need reasonable ventilation to protect against humidity-related problems such as powdery mildew. If there is not enough airflow around your plants, you’re basically creating an environment where they are subject to diseases. Being able to open vents and doors, or roll up the sides, is required for fresh air in better weather conditions.
While this might seem to be an obvious requirement for a greenhouse, it’s not. Some companies do not provide shelving with their greenhouses initially, where others work it into the frame itself to use it to reinforce the frame. Still others provide shelving but make it modular, so that you can adjust the level at which your plants are sitting to provide various heights. For me, the modular shelving is the best choice, especially when I’m starting new plants. However, your needs may vary.
If you have a priceless collection of tropical, humidity-loving plants that you maintain in a climate-controlled greenhouse, you might be wondering about the security and protectiveness of your greenhouse. Other high-value or attractive plants may also need something which can be closed off entirely, keeping unwanted guests of either the two-legged or four-legged variety out.
While it is rare to find a greenhouse with a locking door, some of the hardshell options offer at least the option of sliding a separate lock through to secure your plants. If you’re just protecting your catmint collection from the neighbor’s prized felines, this might not be required, but it’s always good to know that this option is occasionally available!
One important thing to know about greenhouses is that there are hundreds of types out there. If you don’t find what you specifically need for your growing needs right away, keep looking, because it’s likely already available if you search for it.
But allow me to offer some great starting points for your search, and talk about some of the better greenhouses on the market right now and what they’re best for.
Best Small Greenhouse
Gardman R687 4-Tier Mini Greenhouse
- Ideal for small backyards or homes where space is...
- Gives seeds, seedlings, and young plants an early...
- Clear polyethylene cover and roll-up zippered door...
|Type:||Softcover, small size|
|Material:||Tubular steel, polyethylene|
|Dimensions:||27” wide x 18” deep x 63” tall|
|Features:||4 shelves, comes with metal stakes and guy lines for wind protection. Roll-up zippered door in front. Replacement cover available.|
This is actually one of my favorites on this list, and for good reason. Sometimes, you just don’t need a whole lot of greenhouse space, and this provides just enough room to get the seeds started in the colder months. If desired, it can be used indoors as it has a small enough footprint, which means that in the dead of winter, this can be set up in the garage with grow lights attached to the bottom of each shelf, allowing early preparation of plants for the spring.
I especially appreciate that it comes with stakes and guy lines for outdoor wind support. Very few other polyethylene models offer that extra bit of stability. It does need a little more securing for the shelves, but a couple zip ties do the trick nicely. All in all, my pick for the best small greenhouse kit is a great choice that will work for people who don’t need much or are limited on space.
Best Portable Greenhouse
Quictent Portable Cloche
- 【ITEM EXACTLY MATCH THE...
- 【OVERLONG COVER DESIGN】---- Makes greenhouse...
- 【UPDATED DESIGN 2 LARGE DOORS】----2 doors can...
|Type:||Softcover, medium size|
|Material:||Powder-coated steel, waterproof PVC cover|
|Dimensions:||71” wide x 36” deep x 36” tall|
|Features:||Cover has four zippered access/ventilation portals that can be tied open. Designed to sit over a narrow, long plot. Only 3’ tall. Portable in design and construction.|
While generally I don’t find a need for portable greenhouses as they are, in essence, fancy cold frames, this one is useful. Lightweight and easy to move around, it can provide quick protection if the weather turns chilly. This portable greenhouse kit is quite simple to construct. It’s not very tall, so it would not work over massive tomato plants or climbers, but it can be secured with ropes and stakes (not included) to the ground to provide some protection from wind. All in all, if you want something you can move around quickly, this is a great choice.
Best Large Greenhouse
MELLCOM 26’x10′ Greenhouse Tunnel
- 【12 ROLL-UP SIDE WINDOWS】-The green house...
- 【HEAVY DUTY STEEL FRAME】-Walk-in Garden...
- 【TRANSPARENT PLASTIC COVER】-The tough, durable...
|Material:||Powder-coated steel, rip-stop clear nylon|
|Dimensions:||10’ wide x 26’ deep x 6.6’ tall|
|Features:||Extremely large. Sturdy and heavy-weight for wind and weather resistance. Has built-in half-moon mesh vents on either end. Roll-up doors on either end for easy access.|
The Mellcom greenhouse is an excellent growing environment, and it’s massive. Intended for people who are doing hydroponics or who are selling young plants, or even for smaller farm seed starting ventures, this greenhouse is multifunctional. It is strong and protective of the plants within, and can be a very good choice for people who are setting up a larger-scale natural light grow tent on their property. Overall, there’s no question that this has to be my pick for best large greenhouse.
Best Heavy-Duty Greenhouse
Palram Snap & Grow
- Item may ship in more than one box and may arrive...
- Crystal clear virtually unbreakable polycarbonate...
- Reinforced, double wall & rust resistance aluminum...
|Material:||Aluminum with UV-resistant polycarbonate roof and side panels|
|Dimensions:||6’ wide x 8’ deep x 7’ tall|
|Features:||Very snow, wind, and rain resistant. Has built-in roof vents and a split door for extra ventilation. Polycarbonate panels filter UV rays and offer about 90% light transmission to the plants inside. Extremely pest and animal-resistant. Requires gloves and some tools to assemble.|
The Palram Snap & Grow is another of my favorites. If you want something that truly will withstand all weather conditions, this is the ideal choice, and it is set up in a way as to make it comfortable to work inside. The polycarbonate panels allow about 90% of the sunlight to filter through to the plants, which can be very useful in warmer environments (especially if the top half of the door is opened for heat release), and there are good vents in the roof as well. Just be sure that it is placed on very level ground!
Other Good Choices
Giantex Garden Portable Wooden Cold Frame/Greenhouse
- Foldable Top-- Two top parts of this product could...
- Beautify Green Spaces and Large Capacity-- Big...
- Solid Structure--Structured with heavy-duty wood...
|Material:||Wood, polycarbonate glazing board|
|Weight:||Weights vary depending on size|
|Features:||Depending on model, it either has a hinged top opening with locking arms or front doors. Solid construction, easily able to handle snow, rain, and wind conditions. Smallest model sits directly on the soil like a cloche, but other models can be like a potting table/cold frame hybrid, a true small greenhouse, or a cold-frame style with open bottom.|
There are a variety of styles produced by Giantex, all of which fall under the same category. All of them offer wood frame construction which is stylish and can offer visual appeal in the yard, but each style varies. Whether you opt for a fancier cold frame or a cabinet-like small greenhouse, these hardcover options are wind and weather-resistant.
Rion Sun Room 2
- Quickly and easily cover your porch, deck or patio...
- Roof panels are 100% UV protected, 4mm twin-wall...
- 3mm translucent acrylic wall panels are 100% UV...
|Material:||Resin frame, dual-pane polycarbonate panels.|
|Dimensions:||Sizes range from 6’ x 6’ to 8’ x 20’.|
|Weight:||Varies by size, smallest is 176 lbs and largest is 568.1 lbs.|
|Features:||Dual-pane window panels provide an extra layer of insulation from the weather outside. Vents in roof panels, along with a secure exterior door. This is designed to be attached to the side of a house, so has three walls + sloped roof.|
Let’s say you have a large house, a large yard, and want something that you can relax in while gardening. Does this sound like you? If so, the Rion Sun Room is a phenomenal option. It attaches to the side of the house and creates a secured sun room that you can work in, even in the most inclement of weather conditions. Better yet, it’s dual-paned window panels, which provides great insulation for a windowed room. If you have extra money and want the best-looking greenhouse available, this is your pick.
Greenhouse Geodesic Dome
- Galvinized Steel Frame 1/2"
- Frame will withstand high winds and hurricane like...
- Geodesic Design - Great in high winds and...
|Type:||Semi-hard cover, large|
|Material:||Galvanized steel frame, 7mil Marine poly shrink cover|
|Features:||Securely-closing front door. Can be rigged up with internal fans and heaters as necessary, and has an optional cedar door available. Cover is shrunk down on the frame to provide a tight seal that makes it incredibly weather-resistant and thickens the plastic. May require additional vents or a screen door to allow for heat to escape.|
If you live in New York or other areas which get heavy snows in the winter, you scoff at anything soft-covered normally. However, you shouldn’t scoff at this 16-foot circular geodesic dome. While yes, the material is a flexible poly shrink cover, once you have shrunk it down onto the frame it becomes semi-rigid and thicker. This greenhouse kit comes with a heavy-duty geodesic dome frame and the marine-grade poly shrink cover, as well as thorough instructions. If you want something large that can house a good-sized growing environment, and need it to hold up through even the coldest of winters, check this one out.
Whether big or small, hardshell exterior or soft PVC or polyethylene, there is a greenhouse that will fulfill all your needs. Depending on what you plan on using it for, you should be able to find a great pick from any of the options I’ve suggested, or keep searching until you’ve located your dream greenhouse!
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Last update on 2021-10-20 / Affiliate links / Images from Amazon Product Advertising API