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Riga Greenhouses

The Riga Greenhouse units are one of the strongest greenhouses you can buy for the money and are attractive and fits well into any upscale garden setting. The range of Riga Greenhouses offers more window and door ventilation than any other units in its class. The twin-wall polycarbonate glazing on the Riga Greenhouse is German-made and believed to be of superior quality to the much more common Polygal or GE glazing.

The unique "Onion" shaped design of a Riga Greenhouse offers optimal headroom inside, but with enough slope on the outside so that heavy snow loads slide down and severe winds easily pass over the greenhouse

What makes Riga stand out?

Riga Greenhouses are truly the European definition of a greenhouse - to grow fresh vegetables, herbs, and flowers in the middle of the harshest winters.  Other Greenhouses brands use less than 8 mm twin-wall polycarbonate which can only be used when only a slight night frost might be expected during the spring or fall season. At best they can only be used to house established plants during the winter season but are not the best choice for the sub-zero weather.

One major advantage of Riga's construction method is that the frame profiles are permanently attached to each other, and won't come loose over time due to wind pressures. The "onion" has no eaves or shoulders giving it significantly less wind resistance. The Riga Series is the only greenhouse with an oversized, hinged, rear wall window at 42" tall and 30" wide and an oversized adjustment arm roof window 40" wide and 24" deep (equivalent to 2 regular size roof windows).

Riga Greenhouses also have one of the best ratios between aluminum framing and twin wall polycarbonate panels, which allows for maximum light transmission and less "moving" shade.

Riga III Greenhouse is one of the most popular models in Riga. With a combination of strong materials and durable hardware, the first Riga III Greenhouse was considered by far the strongest greenhouse under $5,000. This Greenhouse measures ten feet in length and offers both seven and nine-foot width options with up to 102 internal square feet. Now whether it is the extreme Nebraska weather or the extremely harsh new England weather, Riga greenhouses have you covered.

Riga Greenhouses comes in different ranges.

Riga XL Professional Greenhouses - 14' wide, up to 29' 6" long Riga XL greenhouses can be used professionally or in your backyard. They share the signature shape and strength of their smaller siblings while providing ample space for the largest of gardens

Have lots of fun and success with Riga greenhouses by Hoklartherm and enjoy the fruits of your labor! 

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Why Buy a Riga Greenhouse?

  • Riga Hobby Greenhouses have a special shape, which is designed to offer optimal headroom inside, but with enough slope on the outside so that heavy snow loads slide down and the severe wind blows right over

  • Comes with a large Dutch barn-style door and a keyed lock

  • The unique design of the Riga Greenhouse Kit has the best ratio between aluminum framing and polycarbonate panels, which allows for maximum light transmittance and less “moving” shade

  • Comes standard with an oversized rear-wall window for better ventilation

  • Riga S & L: 8 mm twin-wall polycarbonate glazing as side panels & 10 mm twin-wall polycarbonate glazing in the front and back walls

  • Riga XL: 16mm triple-wall polycarbonate on all sides

  • Compared to the Riga S line, the Riga L and XL have more headroom and space in square feet

  • Designed, Engineered, and Manufactured in Germany with 30 years of experience

Where is Riga Greenhouse made?

Designed, engineered, and manufactured in Germany by Hoklatherm, a leading manufacturer of commercial and hobby greenhouses, sunrooms, pavilions, pool covers, home additions, and commercial buildings, with 28 years of experience. The RIGA Greenhouses are a true representation of a European Greenhouse - designed to be used to grow fresh vegetables, herbs, and flowers in the middle of winter.

How do you install a Riga Greenhouse?

You will find the assembly of the RIGA greenhouse to be quick and easy if you carefully follow these Assembly Instructions. The assembly requires only two people, but it will go quicker if you have access to a 3rd person who can help from time to time - this person does not need to be especially strong or handy.

Contents: Hoklartherm inspectors carefully check the contents of each package. Nonetheless, we ask you to do the same: Check the contents of each package against the table of contents in this Manual.

Choose the best location: Please choose, if possible, a sunny and protected location for your greenhouse. Avoid heavily shaded near buildings and/or trees. However, also be careful to avoid bright, direct sunlight (especially in the Southwestern part of the United States). High-intensity sunshine is not good for more than a few hours a day. In such areas, some protection from trees and/ or buildings is recommended. Shade cloth might also be needed (ask your supplier for details). For greenhouses intended for growing fresh vegetables such as tomatoes, cucumbers, and melons we recommend the greenhouse be located in a north-south direction, and for those to be used for flowers and pot plants orient it in an east-west direction.

CAUTION: Do not attempt to assemble the RIGA greenhouse while the wind is blowing - your Glazing Panels might blow away. Do not expose the Panels, with their special protective film, to bright sunlight, or the film will become permanently glued to the Panels before the film is removed during installation.

Getting started with Hoklartherm Riga greenhouses:

1) The Riga Greenhouse assembly has to be executed by at least two people - a 3rd person to help out from time to time is recommended!

2) Work cautiously, with the proper tools. Make sure that the stepladder’s footing is secure!

3) We recommend that you work with gloves (although all of the edges have been filed, it is always possible for you to be cut when handling either the aluminum or polycarbonate parts).

4) To get the best results try using one of the heavy-duty seed trays to efficiently grow your plants on the shelves.

Suggestion: Before you begin - read all these instructions to become familiar with each step of the assembly process. You might decide that you find it easier to complete the assembly process in a different sequence. Several sequences are possible. For example, some people may prefer to build all of the greenhouse frames first and then insert the Glazing Panels, while others may prefer to interchange these steps.

Riga Greenhouse Manual

RIGA Greenhouse Maintenance

The Riga greenhouse only requires minimal care and/or maintenance:

  • To clean: We recommend a treatment similar to those for washing your car: Rub with a soft brush and lots of water (very mild soap). Never use abrasive materials as you do not want to scratch the UV filter on top of the Glazing Panels.

  • The pressure cylinder of the Automatic Window Opener should be removed during frost season and be kept frost-free. The rod assembly of the Opener can stay in the greenhouse. Tie the rod assembly arms together with string or wire while the cylinder is not in place to prevent the window from blowing open in stormy weather.

  • Your RIGA greenhouse should be ventilated as much as possible especially when condensation develops. (However, high humidity is preferred by some plants and especially during the seed-to-seedling stage).

What are some of the best accessories for the twin wall polycarbonate greenhouses?

Certain accessories can help optimize the greenhouses and withstand extreme weather conditions, especially in North America. Be it the hurricane-force winds, the cloud-filled days, or the erratic north Atlantic climate, Riga greenhouses can help grow plants year-round starting in Spring and then season extension towards the end of the year. Let us look at some of these accessories that go beyond the very beautiful summers and past winter times as well.


Heater-powered Riga heated greenhouses are a blessing during the winters, especially because of the pretty extreme weather making the conditions unsuitable to grow fresh vegetables and even flowers that constitute the fancy flower baskets.


While a tall wide unit might offer a lot of space, look for removable shelf inserts to optimize the use of vertical space. Moreover, it adds structure to your greenhouse. Multiple options for the bottom and top-shelf retail at affordable prices give you the best value for your money spent.

Windows and vents

Additional roof windows and vents are always a good option even among the strongest greenhouses to ensure optimum airflow and controlled temperatures.

Grow lights

Giving your plants extra light hours can help improve the yield and that is where to grow lights and even hanging lights play an important role. While the sun heats the solar-powered lights, electrical options are also available.

Water Systems

A proper irrigation system is essential to create the perfect growth environment. So based on multiple factors involved, choose an accurate water system. The system retail is based on these factors.

Door Kits

Most green houses come with installed doors, but gardeners often upgrade their door kits based on personal preference and requirements such as the very famous dutch door setup. While optional, it is a useful accessory.

Riga greenhouse is perfect for you if you…

  • Want a well-engineered greenhouse: Made in Germany

  • Want to grow tall plants year-round: Riga S & L has 8-10mm Polycarbonate glazing, Riga XL has 16mm Polycarbonate

  • Need a greenhouse that has to survive heavy snow loads and wind

  • Are looking for a sturdy little greenhouse yet powerful enough to withstand hurricanes

  • Are looking for a long warranty: 10 years on Polycarbonate, 15 years on frame

  • Want great insulation on your greenhouse: Heavy-duty rubber seals and Silicon caulk around windows

  • Need more light for your plants: The shape optimizes the incidence of light

  • Want the perfect growing environment for your plants: Riga provides great light diffusion and ventilation with roof vents, automatic vent openers, barn-style doors, and a rear wall window

Riga greenhouses are not for you if…

…you don’t care about quality and are looking for one of those basic budget-friendly hobby greenhouses.

When you have finished the assembly of a Riga greenhouse, we are confident you will be completely satisfied with the quality of the product.

Financing is available on all Riga Greenhouse equipment.