Build A Portable Greenhouse



We selected the Bloom Walk In Greenhouse to house our seedlings for our annual vegetable garden. The greenhouse is easy to move which might be necessary during the full gardening season. The structure has ample space for seedling trays. The poly cover is reinforced and cuts out some of the strong sun rays.

Getting Ready For Spring Planting

It is late March and I'm getting anxious to get my garden going.  I got the garden beds cleaned out a couple of weekends ago.  Although are all ready to go it's still too early to set plants out this year so I thought I'd try something new, a seedling greenhouse.  A quick trip to my nursery netted me a nice little five by five (by 6 foot high) greenhouse.  Ok, so it's not a big fancy greenhouse but it is a simple little structure covered in reinforced plastic.  Let the fun begin!
raised bed garden prepared for planting
Our raised garden beds, cleaned and prepared for spring planting.

The Bloom Walk-in Greenhouse

bloom green box My Tinkertoy Style Greenhouse

Truth be told I've always been fond of putting things together.  Someone in the house need a new Ikea bookcase?  I'm the one assigned to the assembly task.  So, this new greenhouse structure was right up my alley.  The greenhouse is packed neatly in a 14"x37"x6" box.  The whole thing weighed about 24 pounds so easy enough to lug around.

The structure is made up of several lengths of metal tubing which have been coated in green weather-resistant paint.  The fittings are all sturdy plastic.  The cover is made of heavy, reinforced polyethylene.  The shelves are fairly lightweight wire.  This is probably a good time to mention that this structure won't take a lot of weight on the shelves.  Once assembled I place a clay pot that probably weighed about 6 lbs. on the shelf and the shelf appeared to be very strained.  I would suggest this greenhouse be used for light plastic pots only or for starting seeds in shallow, not too heavy, trays.

One very nice feature of this inexpensive greenhouse is that it is 6 ft. tall so you can walk inside and move around.

Step 1: Prepare The Site

I had scoped out a spot in the yard for the little structure before I purchased it.  The next step was to prepare the site where I wanted to place the greenhouse.  I happen to have an area located on concrete.  Clearly you could set up your greenhouse on dirt.  If you do that then you will want to weed it, and put down a weed barrier that will allow drainage.  Don't just use poly sheeting or you'll have water puddling in the greenhouse, which is not a good thing.  If you don't have a good garden shop in your area then a good online source is Charlies Greenhouse Supply.

So, starting with concrete as a pad I didn't have to worry about weeding or weed-barriers.  However, I did have to do some trimming and clearing to make enough space for the little structure.

The Area Mid - Preparation

area cleanedarea mid preparation

I just had to do a little weeding, trimming and sweeping.  With the area cleaned up I can now start the building.

Step 2: Sort And Inventory Parts

You may be tempted to skip this step but you'll save yourself a lot of aggravation if you don't.  Once I sorted out the big stuff I had to go through that big bag of fittings.  The instructions (see below) do include a little sketch of each of the fittings as well as the quantity you should have on hand in order to do the assembly.  And that, is the reason you want to inventory your parts.  There is nothing more frustrating than getting 75% done only to find you are missing parts.  This happened to me on my last project (building my Ikea bookcases).   At least if you know from the start you may have time to get back to the store to rectify the situation or know that your project is on hold until the problem is sorted out.
inventory greenhouse parts
This is a picture of the shelves, tubing and the big bag of fittings.

small greenhouse parts and fittings
Here are my small fittings sorted out and my instructions.  It wasn't until I was about 1/2 done with the project that I noticed each part had a letter embossed into it.  That came in very handy because there were 3 parts I could not identify because they all look so much alike.  Fortunately I had not misused any parts before I noticed.

Step 3: Assemble Frame

Although the instructions were not stellar, they were certainly adequate.  A single illustration shows the list of parts which correspond to the drawing.  In most cases this was sufficient.  There was no guidance as to where one should begin so I just started with the first #3 rod, built the right side of the frame up to the first level, then the same with the left side of the frame.

greenhouse directions
The connectors just pressure fit onto the rods.  I just had to make sure I had the correct connector pointed in the correct direction.  Although I had a helper this could have been easily done by one person.  If the frame looked a little off-kilter at any time then I would just go back through and press the rods in that area more deeply into the fitting.  This kept the structure squared.  The whole assembly took about an hour and a half. 

partially built greenhouse frame

This is the right side of the frame built up.

greenhouse frame completed
This is the frame completely built.  One thing not clear in the instructions (but becomes apparent later) is that the 3rd #3 rod goes at the upper back of the greenhouse.  With this completed, all is left is to add the shelves and place the cover over the frame and use the ties provided to hold the cover to the frame.


When you go to put the shelves in place be aware you may have some "gaps" so the shelves don't quite fit.  This will be because your frame is a little out of square.  To fix this, just press the rods in the area further into the fittings.  Most likely one or two is just not pressed in the fitting far enough.  We had 2 shelves with this problem and it was very easy to find and fix.

Step 4: Place The Cover Over The Frame

This was the step that would have been difficult to accomplish alone.  I had one person (taller than I) place the cover over the top while I worked around the sides to slip it over the greenhouse, kind of like a large plastic pillow case.  As we struggled a bit I found it helped to unzip the door section to give more room to spread the cover over the frame.

Here is the frame with the plastic cover in place.

greenhouse with cover in place

Step 5: Securing The Greenhouse To the Ground

In my situation I was able to place the structure between two fences where it fits pretty snugly.  It is on a concrete pad so I can't use the small stakes provided.  I have not worked out the details of this yet but I suspect I'll find a way to attach the greenhouse to the fence. While this is not typically a windy area, we can get some winds in the spring that come in off the ocean.  It will be best to secure it.

stakes to hold greenhouse in place

These are the small stakes provided for attaching the greenhouse to the ground.  They are pretty short so I would be concerned they might not keep this light structure on the ground if it became very windy.  You can find good greenhouse stakes at an online greenhouse supply store. Again, we recommend Charlies.

Do not skip this step.  These are very light structures and even a medium size gust might land the sucker in your neighbors back yard with seedlings and plants flying.  If you do a little searching on Amazon you can read some reviews by people who had this happen.

Some Greenhouse Issues

This was an easy to build and very inexpensive structure.  We paid about $99.00 but I've seen some on the web for less.  Here are some tips that will be helpful.
  1. Avoid using the zipper constantly, they seem a bit fragile and most likely will not hold up with excessive use. Because you'll use the door for ventilation, you may want to just open and close it once a day if possible.
  2. When installing the cover over the frame, make sure it is properly aligned on on sides.  If it is not aligned you'll put excess strain on the zippers when you go to close up the greenhouse.
  3. Locate your greenhouse in proximity to a water supply or a hose that will reach.  Ideally you don't want to have to lug a watering can a long distance all the time.
  4. Buy a thermometer for the greenhouse.  Temperatures can vary greatly and excesses can harm your plants.
  5. Don't overload the shelves or they could collapse.

Greenhouse All Built Ready To Use

greenhouse with door opened
Click image to enlarge

Determine Your Temperature Range

Once we had the structure up and in place it was time to determine what temperature range we could expect.  Clearly this will change day to day throughout the year.

dickson recording thermometer

dickson recording thermometer

We happened to have a Dickson Recording Thermometer, a handy gadget that records, on paper the temperature during any 24hr period and keeps a weekly chart.  We placed the thermometer in an area that would not be in direct sunlight so that our reading would be as accurate as possible.   So starting at about 3:00PM, the temperature went up to 80 degrees, down to 60 degrees about 6PM and dropped to 50 degrees about 3AM. 

Knowing our temperature range will tell us what plants we can start or which ones we will have to start later as it warms up.

 Sources and Credits

  • Greenhouse - the product is by Bloom Walk-in Greenhouse.
  • Images: All images by  All rights reserved.

Barbara Bowman graduated with degree in Foods and Nutrition from San Jose State University. As CEO of she spends most waking hours writing, cooking, eating, gardening and traveling.