Mini Greenhouse Construction Details
 (2) 16' Boards 2x8in pressure treated/weather resistant (will be cut to 14’9”) @ Mongers
 (2) 10' boards 2x8in pressure treated/weather resistant (will not be cut) @ Mongers
 (6) 1" PVC pipe 20 ft. long - @ RAM Plumbing Supply
 (1) 3/4" PVC pipe 20 ft. long - @ RAM Plumbing Supply
 (16) 2’ rebar - @ Mongers
 (6) 8' 2x4s for framing and doors – try to salvage 2 storm doors! @ Mongers
 (4) Exterior door hinges (If storm door doesn’t have hinges)
 (2) 3” hook and eye latches or make a latch out of wood @ Lowes
 (10) 4’x1/4” bolts w/ nuts and washers @ Mongers
2” lattice or lath total-120 ft. –for nailing over plastic @ Lowes
Staples- box of T50 at least 3/8” @ Mongers
Duct tape (small roll) @ Lowes
(4) 8” Zip ties or flexible wire- to connect pvc hoops to pvc brace which runs across the top
of greenhouse. @ Lowes
UV resistant greenhouse plastic 25'x20' ~ $50 when bought in bulk (we buy 150' rolls and
can provide the piece needed for $50) Valley Produce Supply.
 1lb box –1.5” nails to nail lath@ Mongers
 1lb box -3” decking screws for assembling the base, doors and doorframes. @ Mongers
 1/4 lb 8d (8 penny) framing nail. Which will be bent over the rebar to connect it the 2x8 frame
@ Mongers
 Exterior Latex paint and primer -small cans for painting pvc pipe @ Lowes
Approximate Total: $225 (less if you use salvaged doors and 2x4’s)
Mini Greenhouse: Introduction
Benefits
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Season extension
Green and warm oasis in the wintertime
Less dependence on grocery stores/ more food from YOUR garden
Better temperature regulation for starting your seeds at home
Warm composting through the winter
Aquaponics – raising fish and filtering the water with edible plants
Plants
These greenhouses are great because you can start your own plants from seed, and you can also extend your season
through the winter (more on this below). Start any plants for your summer garden inside and then transplant them out.
Good winter crops to grow inside the greenhouse are: beets, carrots, turnips, cabbage, kale, lettuce, spinach, broccoli, salad
mix, and any other frost hardy vegetable. These plants are more tolerant to cold temperatures and frost. The key to having
veggies through the winter is to have them at their harvesting size before the first frost in mid-October. This means sowing
the seeds in early to mid-August. You can also get a head start on summer veggies like tomatoes, basil and peppers by
planting your earliest rotation in the greenhouse. Four Season Harvest by Elliot Colman is a great book to read regarding
season extension.
Heating
While the temperature in your greenhouse will stay warmer than it is outside, it is important to keep your plants
warm during the winter, especially at night when temperatures fall below freezing. Choose one or several of these options
(or create your own!):
 Floating garden fabric row cover – this cotton fabric is a great way to keep plants warm and safe from
insects/animals. Using this with the protection of the greenhouse will help keep your plants warm over the
winter. Lots of local organic farmers in the area use row covers; build a connection with a local farmer and
they will gladly give some of their seconds in the fall.
 Cold frames – using cold frames in addition to the greenhouse will generate a good amount of protection and
heat for the plants. These are wood frames topped with glass tilted at an angle towards the south. Four
Season Harvest also has a great cold frame design.
 Thermal Mass – by placing rocks and/or dark colored water jugs inside the greenhouse you can have
prolonged heat. Rocks and water store up heat throughout the day and then release that heat slowly
throughout the night.
 Compost bioheater – building a compost bin inside of the greenhouse will add heat through the process of
decomposition. Adding worms to this process will help speed it up and give yummy worm castings to
fertilize the soil. You could have chickens or rabbits above the compost bin. They will add their body heat
into the greenhouse, fertilizer into the compost, and it will speed up the composting process. Not to mention
entertainment!
 Blankets – with cold frames, simply covering them with several blankets in the evening has been enough to
protect the plants from frost. Doing the same in the greenhouse should insulate the plants over night.
Ventilation
Especially in the summer, it is important that your greenhouse has proper ventilation so that it does not over heat.
Temperatures around or over 100 degrees will scorch your plants. A door on both sides of the greenhouse will provide a
cross breeze. In winter the doors can remain closed all the time. In the spring and fall you may want to have the doors open
only during the day. In the summer the doors should be open all the time. You can purchase a thermometer to monitor the
temperature inside your greenhouse.
Watering
Since your plants will be under the cover plastic, you will need to water daily even if it is raining outside. In the
summer, you may want to water twice daily depending on your site needs. Soaker hoses can be installed when you have
plants growing directly in the ground, but hand-watering flats of plants is recommended. Particularly in the winter, you will
want to water in the morning so that plants don't freeze overnight.