A Rion Grand Gardener Greenhouse Review – HG7216C


The Rion Grand Gardener Greenhouse, Model HG7216C

This Rion Grand Gardener Greenhouse is 8 feet wide, 16 feet long, and 7.8 feet high at the peak of a barn-shaped roof.  That gives you 128 square feet of growing space with plenty of headroom and space for adding a few hanging plants.

Rion Greenhouse HG7216C dimensions.

Heavy-duty extruded resin frame.


The frame is composed of heavy-duty extruded plastic resin…which is supposed to provide enhanced insulation and durability.  A look at the assembly instructions reveals that the frame is constructed using a unique pin and lock design.  I estimate that over 90% of the entire greenhouse assembly is using this pin and lock system.  There are a few screws here and there.  Some are in the door frames, some are in the roof vent latch, and some are on the top of the gable from front to back.

NOTE: It doesn’t hurt to add a bit of Loctite to the pins and screws as the frame is installed to firm-up the structure and keep it from loosening up in high winds.

There is one easily accessible entrance through a set of double doors.  The doors have 2 fence gate style sliding latches placed vertically and they don’t always line up and stay in place sufficiently.  There has to be a better way to secure them!

Double doors with handle.Vertically placed sliding latches top and bottom.








Two types of almost unbreakable, high impact resistant, 100% UV protected polycarbonate panels are used:

  1. The roof panels are twin-wall and 4 millimeters thick, diffusing greater than 90% of the sunlight for even distribution to the plants.
  2. The sidewalls are crystal clear polycarbonate.

In this price range, I would have expected the twin-wall roof panels to be 6 millimeters thick…and, the side panels appear to be a bit flimsy, too…only held in place by means of slots in the frame structure.

There is only one roof vent so, to thoroughly ventilate this greenhouse, the doors will have to be opened, too.  Additional roof vents can be purchased but, for such a pricey greenhouse, I would have expected the manufacturer to include at least 2, if not 3, roof vents.  And, the hinges on the roof vent are insufficient…there are reports of roof vents blowing off in moderately windy conditions.

The manufacturer is adamant that this Rion 8 x 16 greenhouse be built on a perfectly level and square area.  A concrete pad or heavy timber foundation is suggested.  They offer an optional base kit to add height and extra stability.


Can I Offer You Some Assembly Advice?

If you like this greenhouse enough to purchase one, add the option to have it professionally assembled.  This option is less than $200 and it will save you time, effort, and stress…because, there are an endless assortment of parts and pieces.  Unless you are a diehard do-it-yourself-er, you are better off comfortably sitting in a lawn chair sipping a drink and watching this beautiful greenhouse being raised by the hands of people who have done this many times before.

A solid immovable foundation such as a concrete pad or a form made with 4×4 treated lumber is the best base for this greenhouse.  Holes in the frame allow the greenhouse to be securely attached.

For extra windy conditions, adding some U-posts, at least at the corners would be a big help!

For Arctic weather type of conditions where even your breath freezes on your face, temporarily adding some bubble wrap to the panels can give you the added insulation properties to save your precious plants from turning into icicles. Of course, you will want a good infrared heater, too!

A rubber seal is provided to go around each of the clear wall panels but, it is not adequate.  So, using some clear silicone caulk would be most appropriate.

An excellent cleaning agent for the greenhouse polycarbonate panels is Physan 20.  It is a tried and true fungicide, virucide, and algaecide disinfectant.

And, to renew the UV protection and make the panels look new again, I recommend 303 (30306) Marine UV Protectant…but make sure to follow the detailed label directions when using it.

Rion, the manufacturer, has recently reduced their list price by over 20%…mainly because, I think, they have taken notice of some of the design flaws I’ve mentioned in this review.  Now, this Rion Grand Gardener 2 Clear Greenhouse HG7216C is worth the purchase price.  You can use the savings to make the necessary upgrades and improvements and truly make this a solid investment that you can enjoy for years to come!

Tell me what you think in the comments section below or by email: jim@perfect-vegetable-garden.com.


Jim, the Life Long Gardener

2 thoughts on “A Rion Grand Gardener Greenhouse Review – HG7216C

  1. Corrine Reply

    Hi Jim,
    Great, review! My husband is an avid gardener and we’ve recently moved up north from California which has shortened his growing season considerably. I’m not the one with the green thumb, but is there anything you can’t grow in a greenhouse? We can’t even get squash to grow well up here!

    • Jim Reply

      Hi Corrine,

      I’m glad you liked the review for this Rion greenhouse!  You will find that you can grow anything in this greenhouse including squash…especially if you try the bubble wrap technique I mentioned for added insulation, as well as a good infrared heater like the one I reviewed in Greenhouse Accessories.

      Then, you, will be harvesting healthy, tasty veggies before you know it!


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