Farm and Garden

Build a home greenhouse for under $20

I’ve got to hand it to Farmer Marty, he has an awesome greenhouse setup. (see Get your Garden On, Step 1.)  He’s been working on it all winter, and it’s amazing! (Stuff like building greenhouses, by the way, is what farmers do in the winter.   Or at least, it’s what we’ve been doing.  I get asked what I “do all winter” all the time. If you want to know, read on.)

So, Marty’s setup is awesome and very well suited to his small farm.  For a lot of the rest of us though, this extensive or expensive of a setup isn’t possible or necessary.  You might not own a home with a front porch that you can window in, and may not want a germination table rather than a dining table in your kitchen.  If you have a home garden, sometimes it makes the most sense to buy seedlings (I recommend Edward’s Greenhouse and Canyon Bounty Farm, if you live in Boise), but if you’re frustrated that gardening is costing you more than actually buying your food, you can certainly save by starting some of your own seeds.  If you just want to experiement a little, we recommend starting with Brassicas like cabbage and kale, or with lettuce, as these are easier to germinate and more forgiving to keep alive than tomatoes and peppers.

In my case, I have the capacity to start a few seeds in my kitchen window, but they need to be moved outside to a greenhouse with more light as soon as they germinate.  The Global Gardens program owns a small hobby greenhouse:

It works great, but the problem is that it’s on the other side of town.  I have to drive there, and haven’t had much success getting the farmers to drive there regularly to help me with plant care and watering.  I really want to teach the seed propagation part of the process, but doing it at a community greenhouse wasn’t working.  So Farmer Marty had the brilliant idea of building something we could set up right along any sunny, south-facing wall of the farmers’ rented homes.  The frame that you see at the top of the page is the resulting design.  Basically it will lean against a house wall and will be covered in greenhouse plastic to protect the plants.  Plastic flaps will hang down on both sides and be secured with a 2×4 or something else heavy at the bottom.  Plants will sit underneath, on the ground or on a shelf against the back wall.

Here’s how we did it:


  • 6 2X2 boards, 8 ft long, $0.77 each at Home Depot
  • 10 L-shaped connectors for the corners, $0.60 each at the Depot
  • Box of wood screws, I used 1 1/4 inch, $6
  • Linseed oil (Our Home Depot only had a big jug for $25, but you could finish many more projects with that amount)
  • Paintbrush, $0.90
  • Greenhouse plastic (we get recycled stuff for free at a local greenhouse)
  • Electric screwdriver
  • Saw
  • Staple gun and Staples (I forget how much a box of staples was…)

What to do:

Connect four outside boards into a square using connectors and screws.  I predrilled the holes, it’s low quality wood and tends to crack.  Measure the centers of two of the boards and attach another 2×2 crossbeam in the center.  The last board will need to be cut to fit the perpendicular crossbeam of the center “window.”  Marty has a nice saw but you could do this with about any saw, or have it done at Home Depot if you don’t have one.  After making 4 of them and getting some practice, this part of the process only takes me about an hour and a half.

Next, paint the wood with linseed oil and let dry.  This helps protect it from water damage.

Cut plastic to the size of your frame, allowing it to hang long enough over the ends to reach the ground.

Lean against a south facing wall with direct sun, and put plants inside!

One danger with this might be wind, since it’s not attached to your house.  You might want to secure it or take it down in the event of a wind storm.  Great for rented houses though, since there are no permanent attachments.

I’ll be distributing these to farmers this week and starting some seeds with them, so stay tuned for more photos and to see how it goes!


See also:  Build a home greenhouse for under $20, part 2, and $20 Greenhouse, part 3.


2 thoughts on “Build a home greenhouse for under $20

  1. my favorite quote from this post, “may not want a germination table rather than a dining table in your kitchen”

    that’s why I built a window seat. Hope I can start some seeds there. We just use the lettuce container, but maybe I’ll try this if the coop allows it.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s