Update: I have since moved from this house and built a new harbor freight greenhouse with even better upgrades. I’ll include a post of this newer greenhouse soon! this post may contain affiliate links click here for more info.
Is there anything better than walking into a warm, humid greenhouse? The smell of moist potting soil, plant foliage, and flowers all concentrated together has got to be one of the most therapeutic experiences. Like walking barefoot in the sand or eating some really good chocolate. In high school and college I worked at the most beautiful garden center attached to an enormous greenhouse that doubled as an event center. When I walked into that greenhouse I would feel weight and worry from the day evaporate as I walked past the ferns and just breathed in the smell of everything living.
I think many garden lovers, especially those in climates with a full four seasons, fantasize about starting tomatoes in February, getting a head start on growing annual patio pots, and overwintering lemon trees. Building a greenhouse was at the top of my yard to do list when we purchased our home three years ago. It got bumped down the list a bit in favor of things like laying new sod, building a fence, and purchasing plants to serve as the foundation of our landscape. But last spring we looked at our to do list and found greenhouse construction right up at the top. My first choice, a custom glasshouse imported for England for a mere $17,000 was more than a bit out of reach. As I researched different companies and kits I found that for my price range, if I wanted something beautiful it would have to be tiny, and if I wanted something with enough space it would be plain and ugly. I decided for the most price friendly greenhouse for its size, the Harbor Frieght 10’ X 12’.
Making the decision to purchase this greenhouse meant factoring in a bunch of greenhouse improvements to our budget. As silly as it may sound, having a greenhouse that was equal in beauty and function was the goal. I knew my greenhouse would serve as another outdoor room in my garden, and I wanted it to be an escape.
I’d read plenty of negative reviews for this greenhouse. I was aware that the aluminum frame would need some sturdying up, and that the panels would require some work to keep them from blowing out in windstorms. However I felt that for the price, around $500 after a sale + coupon, I could make it work perfectly for our space.
Major Upgrades We Knew We’d Want
- electrical
- ventilation
- automated watering/humidity control
- benches and storage for plants
- potting/work area with a sink
The Eletrical
We were able to add a light fixture and two outlets to the greenhouse. Sometimes I’ll go out in the greenhouse after the girls have gone to bed, flip on the light and do some transplanting. The outlets are a means for us to use the ventilation system we came up with, as well as plug in our seed heating mats or space heaters if we have a chilly night in late spring. The metal conduit through which we ran wires for our ceiling light help add stability to the aluminum frame.
Ventilation
The greenhouse came with four of the roof panels opening as vents. Greenhouse ventilation is important because temperatures in the greenhouse far exceed the outside temperatures during the summer months due to the warm air that gets trapped inside. Although having these events open would allow for some air movement, in order to keep the temperature at a more hospitable range we knew we needed a more aggressive approach to air circulation. We invested in outlet thermostat that can be set for both a high temperature and low temperature range. We have ours set so that at 85°, the outlet turns on the ventilation fan And outlet turns off when the temperature gets down to 80°. This fan pulls warm air from inside the greenhouse outside, it has louvers on the exterior that only open if the fan is running. To allow for fresh air to circulate through the greenhouse we added an opening with louvers across from the ventilation fan, so that when it runs it can pull air from the outside. During the summer months we will hear the fan turning off and on throughout the day as it works to keep the greenhouse in or acceptable temperature range of about 85°.
The thermostat we have has two outlets, one for the fan and one for a heater. I don’t heat my greenhouse through the whole winter. I usually start heating it early to mid March once I have some of my seedlings out there. With this thermostat my heater will kick on when my greenhouse drops below 45, and turn off when the greenhouse is at 50.
Links:
Automated Watering
We purchased and hooked up an automated misting system to ensure that our greenhouse had high enough humidity levels and didn’t simply turn into a desert. We can tell our Mister how often to turn on and for what duration of time. During the hottest summer months I set my misting system to run every 10 minutes for 30 seconds. That kept our humidity up and also helped lower the temperature along with our fan.
Benches
I wanted to be able to utilize as much space as possible, so my husband constructed benches to run down each side of the greenhouse, with hardware cloth for the top level, and 1″ x 3″ slats for the bottom level. The benches are 2″ wide leaving plenty of space in the center of the greenhouse for a removable island when we need extra space, or a table and chairs for our girls’ tea parties.
Potting/Work Area with Sink
This might be my favorite part of the greenhouse. Having a solid work area where I could put down seeds and divide plants was really important. I also wanted to be able to rinse my garden tools, wash my hands, and fill up watering cans. We found our impossibly deep cast iron sink at our local restore, and we used plywood and 2 x 4’s along with our extra hardware cloth make a mold for a concrete counter top. The counter top supports an old, mirrored hutch that we found a secondhand store. I love having the two big mirrors reflecting the greenhouse and the rest of my garden.
Extras
One of the things we kept reading about the Harbor Freight greenhouse was that the panels would blow out in strong wind storms. Reviewers said that the clips holding the panels in work very effective, and that purchasing additional clips was a good option. Instead of adding more clips we ended up using self tapping screws to secure each panel to the frame.
