When most people see a greenhouse or high tunnel, they assume it is there to stay. In the case of the Rimol greenhouses (high tunnels) at Roots Farm in Tiverton, RI, workshop volunteers moved two 50’ by 30’ greenhouses in under ten minutes. Mike Roberts had already disconnected most of the anchors holding down his “Rolling Thunder™” greenhouses.
Nearly 50 participants attended a hands-on NOFA/RI Collaborative Regional Alliance for Farmer Training (CRAFT) Workshop called “Winter Growing with Movable Greenhouses” at Roots Farm in Tiverton, RI. Before moving the greenhouses, Mike and Kelli Roberts discussed how their movable greenhouses help them raise certified organic greens and produce year-round without supplemental heat.
All winter, cold-hardy greens, leeks and root crops grow at Roots Farm in their unheated, moveable greenhouses and low tunnels. The Roberts learned winter growing from Eliot Coleman at Four Season Farm in Harborside, ME. When the outdoor temperature drops, Reemay low tunnels can be set up inside the greenhouses with sturdy wire supports. Carrots, spinach and other greens are easy to harvest inside the greenhouses; cool temperatures make these crops sweet and delicious.
Spring & Summer
In early spring, new vegetables get a head start inside the greenhouses and low tunnels. When the weather warms, the greenhouses will be rolled aside to cover other plots through the summer growing season. During late spring, extra heat can speed crop growth and yield earlier harvests for tomatoes, peppers and melons. Like many southern New England growers, the Roberts raise fabulous tomatoes.
Why a Moveable Greenhouse?
Roots Farm has one of the few movable greenhouses in Rhode Island. The Roberts chose a “Rolling Thunder™” movable greenhouse from Rimol Greenhouse Systems in Hooksett, NH for season extension, crop rotation and crop protection.
Because the greenhouses move on rollers, the Roberts can move their greenhouse with as few as six people. Disconnecting the anchors ahead of time and securing the anchors in the new location takes a couple of hours.
The Roberts’ two greenhouses are moved at least twice a year. The subsequent crop rotation across six 50’ by 30’ plots greatly reduced disease pressures (three plots for each greenhouse). They see healthier tomatoes in their greenhouses than those grown outdoors. Rain and wet leaves do not generate fungal problems for tomatoes grown inside. The extra heat in the green house shortens the days to harvest and extends harvests well into the fall.
The Rimol “Rolling Thunder™” movable greenhouse rolls on heavy-duty wheels with bearings under each set of hoops. The base of the hoops is attached to a specially designed ground post. The wheels roll on a permanent rail (pipe) on top of a weed barrier. The rails are two or more times the length of the greenhouse depending on how many plots the farmer wants to rotate over. Roots Farm, like Eliot Coleman’s Four Seasons Farm, has two greenhouses that move over six plots.
Just two people can roll small Rimol moveable greenhouses. Larger greenhouses may need to be pulled by tractors.
Movable greenhouses from Rimol come in a variety of sizes. Widths vary from 18’ to 34’ and lengths vary from 24’ to 96’. Metal end wall framing kits add stability. Longer lengths require wind bracing.
Rimol’s basic “Rolling Thunder™” movable greenhouse package comes with complete instructions and predrilled steel frames, hoops, end-wall brackets, channels as well as wire poly lock, wheel and miscellaneous hardware. The packages include pipes or tracks to move the greenhouse at least one full length. Two roll-up sidewall kits are available. Farmers with houses over 48 feet long generally add a gearbox to roll up sidewalls safely.
Kits come with 6-mil poly for roof and end walls. The poly is rated for four years under normal conditions (not hurricanes). Some growers select double poly and install an inflation kit. Mike Roberts said, “From what we read of Eliot’s work, the double poly is only worth it when the greenhouses are being heated.”
For ventilation, door and roof vent kits are available. Some farmers want roll-up doors large enough for tractors and equipment access. Smaller farms generally manage with a 36” door. RIMOL offers standard sized doors (3’ wide by 7’ high) at each end of the house. Doors and their frames should be removed during moves.
End wall kits are available with metal framing or farmers can create them of locally purchased lumber. To increase winter insulation and reduce heating costs, some farmers choose triple-wall polycarbonate end walls. The drawback is the smaller doors in polycarbonate ends do not accommodate tractors or medium-sized equipment. The smaller doors also offer less ventilation in summer. Whatever end wall style farmers select should fit their access and ventilation needs.
All Rolling Thunder™ greenhouses are designed for heavy snow and wind loads with extra strength for plant supports or hanging baskets.
The Rolling Thunder™ greenhouse is simple to set up with a few helpers. Rails should be laid out flat on weed cloth or heavy plastic over on a solid base of compacted stone dust. The wheels, ground posts and hoops should be set up all at once with four to six helpers.
The Roberts received a Natural Resources Conservation Service (NRCS) grant to help fund one of their Rimol Rolling Thunder™ greenhouses in 2010. Kelli and Mike believe they have the only Rimol high tunnels on rollers in the area.
The Roots Farm workshop is one of nine Collaborative Regional Alliance for Farmer Training (CRAFT) Workshops in 2013. Rhode Island organic farmers shared their expertise with other farmers, farm workers, apprentices, gardeners and consumers. CRAFT workshops are organized by the Northeast Organic Farmers Association of Rhode Island (NOFA/RI) and funded through a grant from the RI Department of Environmental Management’s Division of Agriculture. For a schedule of future workshops and other NOFA/RI events, click here.
Learn more on the Rimol Rolling Thunder Greenhouse here, call (877) 746-6544 or write Rimol Greenhouse Systems at 40 Londonderry Turnpike, Hooksett, NH 03106. Watch a video of rolling greenhouse here.
A similar story was the cover feature of the February 2014 Eastern edition of Country Folks Grower.