Every greenhouse buyer eventually arrives at the same fork in the road: wood or aluminum? It's a bigger decision than it first appears. The frame is the skeleton of the whole structure — it shapes how the greenhouse looks, how well it holds heat, how much upkeep it demands, and how long it lasts. Choose well, and you'll have a structure you love for decades. Choose based on price alone, and you may find yourself wishing you'd thought it through.
At Mulberry Greenhouses, we carry both. The wooden side is anchored by Alton Greenhouses, hand-crafted in England from Western Red Cedar. The aluminum side includes the Belgian-made Janssens Royal Victorian Greenhouse line and the German-engineered Hoklartherm structures. This guide walks through the real differences between the two materials so you can match the frame to your climate, your maintenance style, and the look you want in your backyard.
Appearance and Garden Aesthetics
Start with the most obvious difference: how each frame looks. Wood has a warmth that aluminum cannot replicate. A cedar frame ages into a soft silver-grey if left untreated, or holds a rich honey tone if oiled — either way, it reads as organic and traditional, blending into cottage gardens, kitchen gardens, and heritage landscapes. Aluminum, by contrast, offers crisp, clean lines and a more contemporary or formal look, especially in the powder-coated black and green finishes used on the Janssens Victorian Greenhouse range.
Neither is objectively better — it depends entirely on the effect you're after. If your garden leans rustic, romantic, or estate-traditional, cedar's natural grain is hard to beat. If your home is modern or you prefer a sleek, architectural statement, aluminum framing gives you that polished edge.
Insulation and Growing Performance
Here's where wood has a genuine, physics-based edge. Wood is a natural insulator — it transfers heat far more slowly than metal. Aluminum, being a conductor, pulls warmth out of the greenhouse through the frame on cold nights, creating what builders call thermal bridging. A wooden frame helps maintain interior temperatures more consistently, which can mean lower heating costs and gentler conditions for plants during shoulder seasons.
Alton's cedar frames use thick glazing bars based on 44x44mm timbers, wide enough that the manufacturer describes them as the strongest greenhouse frame you can currently buy in any material. That mass adds insulation value. That said, premium aluminum greenhouses close much of the gap through smart engineering — the Hoklartherm Riga Greenhouse uses thermally efficient design and thick twin-wall polycarbonate to deliver excellent year-round performance despite its metal frame. So while wood wins on raw insulation, a well-built aluminum structure with good glazing is far from cold.
Longevity and Durability
This is the category where old assumptions mislead buyers. Many people assume wood rots and metal lasts forever. The reality is more nuanced. Western Red Cedar contains natural oils that resist rot, decay, and insects without chemical treatment — which is exactly why it has been used for outdoor structures for over a century. Alton guarantees its greenhouses will not rot for 10 years, and notes that with basic treatment every three years, a cedar greenhouse can last 30, 40, or even 50 years.
Aluminum, for its part, never rots and never needs painting — it simply oxidizes to a stable finish and keeps going. Both materials, properly cared for, can last decades. The difference is the type of care: wood needs occasional re-treatment, while aluminum needs almost none. Neither is a throwaway structure like a cheap steel-and-plastic greenhouse kit.
Maintenance: Be Honest With Yourself
This is the deciding factor for many buyers. A wooden greenhouse rewards a little attention — cedar benefits from a coat of oil or preservative every two to three years to keep it looking its best and maximize its lifespan. For some gardeners, that's a pleasant afternoon ritual; for others, it's a chore they'll resent.
Aluminum asks almost nothing of you. An occasional wipe-down to remove algae and dirt is essentially the whole maintenance routine. If you want a structure you can put up and forget about, aluminum is the pragmatic choice. If you enjoy caring for well-made things and want the beauty of natural wood, cedar's modest upkeep is a fair trade.
Cost and Long-Term Value
Cedar greenhouses generally sit at the premium end of the market. You're paying for hand-crafted joinery, thick timber, and the natural material itself — a decision to buy a Victorian greenhouse in cedar is an investment in craftsmanship. Quality aluminum greenhouses span a wide price range, from mid-market hobby models to premium Janssens and Hoklartherm structures, giving buyers more entry points.
When you calculate value over a 20- or 30-year horizon, both materials justify their cost far better than budget kits that need replacing every few years. The right question isn't which is cheaper today, but which will still be standing — and still beautiful — in 2050.
So, Which Frame Should You Choose?
Choose wood if you value natural beauty, want the best passive insulation, enjoy the ritual of maintaining a well-made structure, and your garden leans traditional. The Alton cedar greenhouse range is the standout here, offering estate-quality craftsmanship built to last for generations.
Choose aluminum if you want minimal maintenance, a modern or formal look, a wider range of price points, and a frame that shrugs off decades of weather with almost no attention. The Janssens Royal Victorian and Hoklartherm Riga lines both deliver premium aluminum performance.
There's no universally correct answer — only the one that fits your garden and your habits. And if you want a structure that doesn't quite exist in either catalog, that's exactly what our custom program is for.
Find Your Perfect Greenhouse at Mulberry Greenhouses
At Mulberry Greenhouses, we'd love to help you weigh wood against aluminum and find the frame that fits your garden. Whether you're drawn to the natural warmth of Alton Greenhouses in Western Red Cedar or the sleek durability of a Janssens or Hoklartherm aluminum structure, we'll walk you through insulation, maintenance, and sizing so the choice is clear. If neither standard option is quite right, ask us about our custom greenhouses — we build to your exact specifications. And be sure to check our today's deals before ordering — our promotions change monthly. We offer free curbside delivery to the contiguous US, military discounts, and a price match guarantee on every order.