Buying guide for best greenhouses
A greenhouse is perhaps the ultimate backyard extra for the avid gardener, allowing you to extend your growing season well into the colder months or year-round.
From small structures for starting seeds to palatial constructions bigger than some New York studio apartments, there is a wide range of greenhouses out there, so how do you find the best one for you?
At BestReviews, we know our readers have their own individual needs, which is why we aim to give you the tools and information you require to select your ideal products. A mixture of lab tests, expert interviews, customer feedback, and good old-fashioned research allows us to produce in-depth shopping guides to help you on your way.
Read our full shopping guide to greenhouses, or head to the top of the page to see our five favorite choices.
Types of greenhouses
Starter greenhouses
Starter greenhouses are small to medium-sized, walk-in structures designed for starting and growing seedlings until they can be transplanted into larger containers or outside beds. They are fixed in place and are covered in glass rather than plastic.
Pros:
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These are perfect for people who ultimately want to grow their plants outdoors but need a place to start the seeds before the risk of frost has passed.
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If your yard isn't exceptionally large, these greenhouses take up less space than big grower greenhouses.
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Starter greenhouses are versatile – they can double as potting sheds.
Cons:
Price: Basic starter greenhouses cost between $300 to $700. Larger bespoke models are priced well into the thousands.
Portable greenhouses
Portable greenhouses are similar to starter greenhouses, but instead of being fixed structures, they're temporary and movable. These are covered in plastic rather than glass.
Pros:
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Portable greenhouses are ideal for people who can't or don't want to commit to erecting a permanent greenhouse (renters, for instance).
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You can move portable greenhouses, if necessary, and pack them up for storage when they're not in use.
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These greenhouses are quick and easy to assemble.
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If you have a small budget, a portable greenhouse is an inexpensive choice.
Cons:
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Portable greenhouses aren't as effective at holding heat as permanent models, so they won't extend the growing season as much.
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These greenhouses aren't as durable as permanent models. Cheaper ones can degrade after a couple of growing seasons.
Price: Depending on the size and quality, you can expect to pay between $50 and $200 for a portable greenhouse.
Grower greenhouses
Grower greenhouses are very large structures designed to grow plants from seeds or seedlings to full-sized plants.
Pros:
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If you want to grow fruits and vegetables all year round, a grower greenhouse is for you.
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Grower greenhouses are versatile. They can be used to start seedlings, grow crops from seed to harvest, as an all-purpose potting shed, or a mixture of all three.
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Most grower greenhouses come with a range of shelving that can be adjusted to meet your needs.
Cons:
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Unless you live in a very warm climate, you'll need heating and lighting in your grower greenhouse in order to use it year-round.
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You'll need a lot of space in your yard for this greenhouse.
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You may need professional help to assemble a grower greenhouse.
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These greenhouses are expensive.
Price: Grower greenhouses start at around $2,000. Large, high-end models cost in excess of $10,000.
Mini greenhouses
Mini greenhouses are small, portable models that generally aren’t large enough to step inside. They come with a number of removable shelves to maximize growing space.
Pros:
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Mini greenhouses are perfect for people who want to start their plants a little early but aren't concerned with year-round growing.
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The compact size makes mini greenhouses a great choice if you're short on space.
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Most of these greenhouses are extremely affordable.
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These greenhouses are very simple to assemble, usually without tools.
Cons:
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A mini greenhouse will likely be too small for the needs of serious gardeners.
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These greenhouses aren't particularly sturdy.
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The plastic covers can become brittle with UV damage after just a year or two.
Price: Most mini greenhouses cost between $30 and $40.
Greenhouse features to consider
Size
The size of the greenhouse you buy depends on your requirements.
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If you only want to start a handful of plants to transplant outside later, a compact greenhouse between 4 x 6 feet and 6 x 8 feet should suffice. Bear in mind that increasing the size by just a couple of feet can give you a lot more usable space for just a little more money.
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If you have serious gardening ambitions – to produce vegetables year-round, for instance – opt for a minimum of 8 x 16 feet. You can find also models as large as 16 x 20 feet.
Shape
Most greenhouses are either square or rectangular, though you can find some hexagonal or octagonal models. As a rule, square and rectangular models are the most practical options. They make better use of the space in your yard, and they're available in a range of dimensions. Hexagonal and octagonal models can be attractive, but they're less readily available, more expensive, and harder to ventilate.
Frame material
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Aluminum: Durable, lightweight, and inexpensive, aluminum is perhaps the most common choice of material for greenhouse frames. It can also be powder-coated in a range of colors, so you can match it to other furniture or features in your yard.
- Wood: People who want a more classic look often prefer a wood-framed greenhouse. While undeniably attractive, these aren't as durable as aluminum greenhouses, and they cost more.
Glazing/cover material
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Horticultural Glass: The most common material for glazed starter and grower greenhouses, horticultural glass is supplied in panes of four square feet that overlap where they join. While relatively inexpensive, this glass is fragile, and the joins are difficult to clean.
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Safety Glass: If you have the budget, we recommend a greenhouse with toughened safety glass. This comes in larger panes, so there are no unsightly, hard-to-clean overlaps. It's tougher than horticultural glass and less likely to break.
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Polycarbonate: A newer glazing option for greenhouses is double-walled polycarbonate. It is tough, lightweight, and extremely well insulated, so it retains plenty of heat. It doesn't let in as much light as glass, however, so it isn’t as good for plants that need a lot of sunshine.
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PVC: Most mini and portable greenhouses are covered with a sheet of PVC. While lightweight and flexible, it doesn’t resist UV rays, and it tends to degrade after a year or two in the elements.
Tips
Before you commit to purchasing a greenhouse, you should decide exactly where you're going to place it and determine that your greenhouse will fit there.
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Orient your greenhouse. An east-west orientation will give your plants slightly more light during the winter; a north-south orientation is better for summer crops. However, if your greenhouse is only a couple of feet longer than it is wide, orientation won't make much difference.
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Position your greenhouse away from trees. If you erect it too close to trees, you’ll have to continually clean leaves off the roof.
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Choose a level site for your greenhouse. Your greenhouse needs a level base, so pick a flat area or have the site leveled.
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Protect your greenhouse from wind. Even the most well-constructed greenhouse isn't impervious to high winds. Place yours near a fence, wall, or hedge to give it some degree of protection.
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Position your greenhouse in a convenient spot. If you have a large yard, you might not feel like going all the way to the far corner to check on your plants before bed.
FAQ
Q. Will I need professional help to set up my greenhouse?
A. Some greenhouses require installation by professionals, especially those that need a proper foundation. Other models can be erected fairly easily, either by yourself or with a helper. If you're unsure, the product specifications should help you decide.
Q. Should my greenhouse have clear or diffused glazing?
A. Most greenhouses have clear glazing because this allows the most light through, making it ideal for starting seedlings and growing plants to transplant outdoors. However, if you want to raise vegetables all the way to harvest, you might want to consider diffused glazing. It provides more even light, which is better at supporting plants through the whole growing cycle.
Q. Will my greenhouse need to be heated?
A. While most people don’t heat their greenhouses, you might want to heat your greenhouse if you intend to raise tropical plants or grow plants all through the winter.
