Yes, a MONT greenhouse can survive winter in most of the US. It has 8mm twin-wall polycarbonate, a heavy American-made aluminum frame, and a rated snow load of 24 pounds per square foot. To keep it safe, anchor it well, clear heavy snow, and add a heater if you want to grow through the coldest months.
We sell and support MONT greenhouses every week, and winter is the question we hear most. This guide covers what the specs really mean, how much snow that is, and how to set up your MONT for a cold-season harvest.
✅ Quick answer
- MONT greenhouses are made in the USA by Riverstone Industries. They used to be called Monticello.
- Rated for 24 lbs/sq ft of snow and 65 mph wind, per the manufacturer.
- Walls and roof are 8mm twin-wall polycarbonate. It holds heat far better than single glass or thin panels.
- Door latches and vent locks for extreme weather are included.
- Unheated, it protects hardy greens. For tomatoes or tropicals in a cold climate, add a heater. The math is below.
What is a MONT greenhouse?
MONT is a line of hobby greenhouses made by Riverstone Industries. The line was first sold as Monticello, so you may see both names. They are designed and made in the USA, and they ship from Georgia.
Every MONT is 8 feet wide and 7'6" tall at the peak. You choose the length: 8, 12, 16, 20 or 24 feet. A 4-foot extension kit lets you add length later.
The line comes in a few packages:
- Standard MONT: the greenhouse itself, with an optional premium package of benches, shade cloth, watering and a sink.
- Mojave Style: a bundled package with extra gear. The product page lists what it includes.
- Growers Edition: light-diffusing panels plus an electric fan system, folding benches, drip watering and a 17,000 BTU heater.
For winter, all of them share the same frame and panel thickness. The difference is how much gear comes in the box.
Can a MONT greenhouse survive winter snow and wind?
Riverstone rates the MONT for a 24 lbs/sq ft snow load and 65 mph wind. That is solid for a hobby greenhouse. It is enough for much of the country, as long as you don't let snow pile up.
Three parts of the design help it in winter:
- A heavier frame. The aluminum is extruded in the US. Riverstone says it uses, on average, more than 40 lbs more aluminum than a typical imported greenhouse. A stiffer frame holds more snow and flexes less in wind.
- Thick panels. The 8mm twin-wall polycarbonate is the same thickness used in many commercial houses. It also won't shatter like glass.
- Storm hardware. New door latches and vent locks keep the doors and roof vents shut in high wind.
⚠️ Know your local snow load: your building department can tell you the design snow load for your area. If it is well above 24 psf, or you can't reach the roof to clear it, call us. A heavier-duty model may suit you better.
How much snow is 24 pounds per square foot?
Snow load is about weight, not depth. Light, fresh snow weighs little. Old, packed snow and ice weigh a lot more. Maine's Emergency Management Agency shares these rules of thumb from the Insurance Institute for Business & Home Safety:
- Fresh snow: 10 to 12 inches weighs about 5 lbs/sq ft.
- Packed (old) snow: 3 to 5 inches weighs about 5 lbs/sq ft.
- Ice: 1 inch weighs about 5 lbs/sq ft.
📐 Snow weight on your roof
Load (lbs/sq ft) ≈ (Depth in inches ÷ inches per 5 lbs) × 5
Fresh snow ≈ 10–12" per 5 lbs · Packed snow ≈ 3–5" per 5 lbs · Ice ≈ 1" per 5 lbs
🧮 Worked example: when does a MONT reach 24 psf?
- Fresh snow: 24 ÷ 5 × 10 to 12" = about 48 to 58 inches
- Packed snow: 24 ÷ 5 × 3 to 5" = about 14 to 24 inches
- Ice: 24 ÷ 5 × 1" = about 5 inches
So a fluffy storm is rarely the problem. Wet snow that freezes and stacks up is. These are rough guides, so clear the roof long before you get close.
💡 Our rule: brush the roof after every storm of more than a few inches. Use a soft broom or roof rake, and push from the inside first by tapping gently on the panels. Never chip ice off polycarbonate with a shovel.
Does 8mm twin-wall polycarbonate keep a greenhouse warm?
It helps a lot. Twin-wall panels have two thin walls with a layer of air between them. That air works like a double-pane window and slows heat loss.
Many cheap kits use thin single-layer panels. Riverstone notes that some clear walls are as thin as 0.2mm. Those panels let heat pour out at night.
🌨️ Clear or light-diffusing panels in winter?
- Clear 8mm panels (standard MONT) let in the most low winter sun, which means more free heat by day.
- Light-diffusing 8mm panels (Growers Edition) spread light evenly and add privacy. Riverstone says you can't see in from just 8 inches away.
- Both have the same thickness, so they insulate in a similar way.
Do you need a heater in a MONT greenhouse in winter?
It depends on your climate and your plants. An unheated MONT can keep hardy crops going through a mild Southern winter. In colder areas, or for warm-season crops, you will need heat.
Here is how to size a heater. It is the same formula we use in our guide to the cost of heating a greenhouse.
📐 The greenhouse heat formula
BTU per hour = Surface area × U-value × Temperature gap
Surface area = walls + roof, sq ft · U-value for twin-wall polycarbonate ≈ 0.7 · Gap = inside °F minus coldest outside °F · Add 20% for safety
🧮 Worked example: a MONT 8x12 on a 0°F night
- Surface area (walls + roof): about 350 sq ft. This is our rough estimate from its 101" x 150" base and 7'6" peak.
- U-value for twin-wall polycarbonate: 0.7 (a planning value from Greenhouse Management magazine)
- Keep it 45°F inside when it is 0°F outside: a gap of 45°F
350 × 0.7 × 45 = 11,025 BTU per hour. Add 20% = about 13,200 BTU per hour. The Riverstone Greenhouse Heating System puts out up to about 17,000 BTU, so it covers this with room to spare.
Want 60°F inside instead? 350 × 0.7 × 60 × 1.2 = about 17,600 BTU. That is right at the heater's limit, so add a small backup heater.
The Riverstone heater mounts on the ceiling, at least 6 feet up. That keeps your benches and floor clear. It runs on a 240V circuit, so plan on an electrician. You can see more options in our greenhouse heater collection.
💡 No power at the greenhouse? Water barrels, stone paths and a sealed base store daytime sun for the night. They won't replace a heater in a hard freeze, but they help. See our list of ways to heat a greenhouse without electricity.
How do you winterize a MONT greenhouse?
Most winter damage we hear about comes from setup, not the greenhouse. Work through this list each fall:
- Check the anchors. Make sure the base is fixed to a level foundation and every bolt is tight. Wind gets under a loose base.
- Lock the vents and doors. Use the included door latch and vent locks before storms.
- Clean the panels. Wash with soapy water, as Riverstone suggests. Clean panels let in more winter sun.
- Clear the gutters. The built-in gutters must drain, or ice can build up along the eaves.
- Test the heater and thermostat before the first frost, not during it.
- Keep some airflow. On sunny days, crack a vent or run a fan for a few minutes. It cuts the damp air that causes mold.
- Plan for snow. Keep a soft broom or roof rake by the door.
Your foundation matters most of all. A level, solid base keeps the frame square, so doors seal and panels stay put. Our practical guide to a greenhouse foundation walks through the options.
Which MONT greenhouse is best for winter?
All MONT sizes share the same snow and wind ratings. So pick the size for your plants, and the package for how much gear you want.
| Model | Size | Heater included? | Best for | Price guide* |
|---|---|---|---|---|
| MONT 8x8 | 8' x 8' | No | Seed starting, overwintering pots | ~$3,149 |
| MONT 8x12 | 8' x 12' | No | A roomy all-round size | ~$4,150 / ~$5,000 premium package |
| MONT 8x16 | 8' x 16' | No | Winter greens plus seedlings | ~$5,099 |
| MONT 8x12 Growers Edition | 8' x 12' | Yes, 17,000 BTU | Year-round growing, ready to go | ~$7,100 |
| MONT 8x24 Growers Edition | 8' x 24' | Yes, 17,000 BTU | Serious growers, big harvests | ~$9,999 |
*Prices checked in October 2026. Prices can change and sales may apply, so click the model name to see today's price.
On the larger Growers Editions, one 17,000 BTU heater has more space to cover. Run the formula above for your size and climate. You may want a second heater for very cold nights.
📌 About prices: manufacturers update their prices during the year, and we often run sales and promotions. The price on the product page is always the current one. Prices in this article are a guide from when we wrote it (October 2026), not a quote or guarantee. Found a lower price for the same model at an authorized retailer? We offer a Price Match Guarantee - please check the rules first. Call us and we will confirm today's price and any current deals.
What can you grow in a MONT greenhouse in winter?
What you grow depends on how warm you keep it. Here is a simple guide we share with our customers:
- Unheated or just frost-free (35–45°F): spinach, kale, lettuce, chard, arugula, scallions and herbs like parsley. You can also overwinter potted figs, rosemary and geraniums.
- Cool (45–55°F): everything above, plus peas, broccoli, cabbage and early seed starts.
- Warm (55–65°F at night): tomatoes, peppers, citrus and tropical plants. Add grow lights for fruiting crops, since winter days are short.
Our guide to growing greens in the chilly season has more ideas for a cool greenhouse.
Which accessories help a MONT in winter?
You don't need everything at once. These are the add-ons our customers find most useful in the cold months:
- A heater with a thermostat. The Riverstone ceiling heater has a built-in thermostat and a thermal cutout.
- Benches and shelves. They lift plants off the cold ground and double your space. See the MONT shelves and workbenches.
- Ventilation. The MONT solar-powered ventilation system moves damp air out on sunny days.
- A 4-foot extension. Add length later if you need more room.
When is a MONT not the right winter greenhouse?
We want you to buy the right greenhouse, even if it isn't this one. A MONT may not be the best fit if:
- Your local snow load is well above 24 psf.
- You get frequent winds over 65 mph.
- You can't get to the roof to clear snow.
- You want a much wider house. Every MONT is 8 feet wide.
For those cases, look at heavier-duty houses such as the Hoklartherm Riga line. Our guide to the most durable greenhouses for wind, snow and harsh winters compares them side by side.
🌿 Our verdict: for most backyards, a MONT is a strong, well-insulated winter greenhouse at a fair price. Anchor it, clear the snow, and match the heater to your climate. Do that, and it will carry you through many winters.
How do delivery and assembly work?
We ship every MONT free to the continental US. It arrives in several boxes. Count them against your tracking number, and report any damage within the window on the product page.
Riverstone suggests two people and a full weekend to build one, not counting ground prep. Prefer help? We list trusted independent crews on our Assembly Crews page. We are a small, woman-owned business in Georgia, and we answer every question personally, before and after you buy.
Frequently asked questions
How much snow can a MONT greenhouse hold?
Riverstone rates it for 24 lbs per square foot. That is roughly 4 feet of light fresh snow, but only about 14 to 24 inches of packed snow or 5 inches of ice. Clear the roof well before it gets that heavy.
Is the MONT the same as the Monticello greenhouse?
Yes. Riverstone Industries renamed the Monticello line to MONT. The design, the 8mm twin-wall panels and the American-made aluminum frame carry on under the new name.
Can I use a MONT greenhouse in winter without heat?
Yes, for hardy crops in mild areas. Spinach, kale and lettuce handle cool nights well. In colder climates, an unheated MONT will freeze on the coldest nights, so add a heater for tender plants.
What size heater does a MONT 8x12 need?
To hold 45°F on a 0°F night, our estimate is about 13,200 BTU per hour. The 17,000 BTU Riverstone heater covers that. For 60°F on the same night, add a backup heater.
What warranty comes with a MONT greenhouse?
The standard MONT pages list a 10-year warranty on the frame and polycarbonate. The Growers Edition pages list 15 years. Check the product page for your exact model.
Is Solexx still a good winter alternative?
No. Solexx greenhouses are no longer made. If you were looking at one, a MONT or a Hoklartherm Riga is the closest choice we sell today.
Planning a winter-ready MONT?
We are a small, woman-owned business in Georgia, and we answer every question personally. Tell us your town, your yard size and what you want to grow. We will help you pick the right size and heater, confirm today's price and any current sale, and connect you with an assembly crew.