Setting up the
greenhouse interior
Setting up the inside of a greenhouse is a very personal thing for a gardener. Everyone has different ideas and uses their greenhouse in a variety of ways.
Do you plan to plant directly into beds or do any container gardening inside the greenhouse? Is the greenhouse just for starting seeds or (please say no to this one) storing gardening supplies? Or, maybe you just need a place to over winter some potted plants.
I do a little of all of the above – I need a storage shed!
We finished building the main structure of my greenhouse right before the cold hit the first year. I didn’t have time to do anything to the inside but I was able to use it to over-winter some plants.
The following spring I started working on the inside of the greenhouse. Due to land space constraints the greenhouse runs from north to south. I installed a permanent raised bed along the west wall that wraps around to the north wall. I chose this wall for two reasons: first, trees growing along the east wall (not on our property) block some of the morning sun; and secondly, due to the slope of the yard, the west wall ground level is lower so I didn’t need to dig in as much.
Even though I live in grow zone 5, I enjoy growing some zone 8-11 plants. A special setup is required for this to happen in my traditional above ground greenhouse. I am not set up to harness geothermal heat. I also don’t have a great amount of thermal mass for a battery bank and since my greenhouse is a bit on the smaller side I don’t want to fill it up with water barrels to accomplish that.
In addition to the heating issues, we are often visited by little critters, such as voles, so while building the raised beds I had the opportunity to plan for this.
After digging down and leveling off at the depth I wanted, I poured a thin layer of concrete. The purpose of the concrete was to prevent critters from digging up into the beds. The concrete would also be completely covered so it didn’t need to look pretty; dry pouring would work here.
I ripped and used rough-cut boards to build the bed. The untreated boards will decay over time but they were a lot cheaper, and I’m not concerned about them leaching chemicals into my garden soil.
Drainage is important for healthy plant growth so at this point I installed a drainage system. I drilled holes along the bottom and sides of a 4-inch PVC pipe. I then cut out a 2-inch hole for connecting another pipe to it which would lead to outside.
Since we were under a great time constraint while building the foundation and didn’t think about a drainage hole until it was too late, digging the drainage canal under the foundation now was the most fun part of this endeavor – NOT.
Once the pipe was installed, I filled in the area around it with untreated scrap lumber and large gravel. I then placed some landscaping fabric over that to keep the soil from seeping into the pipe and added a little more gravel over that. I filled the rest of the bed with soil and compost, leaving about two inches at the top. The two inches at the top will be for the mulch.
When the raised bed was completed, I transplanted all of my zone 8-11 plants into it. There were still a few months to go before cold weather would descend upon us once again, so there was time to wait on constructing a cold frame over the bed.
At this time, critters can still dig into my greenhouse since the only area with concrete is under the raised bed. As time and resources allow, I will pour more concrete to stop them from getting in at all.
In the meantime, I started setting up the rest of the greenhouse.
My kit came with a seeding shelf that attached to the side-wall and ran the full length of the greenhouse. I installed this on the east wall. I placed a shelving unit for seedlings at the south wall.
Because of the possibilities of long cold, winters and heavy snow at our home, I wanted to have the option to grow some cold weather crops inside the greenhouse. Crops like cabbage and kale do fine under snow but having the option to harvest inside the greenhouse is a convenience I appreciate.
I leveled the soil in the center of the greenhouse and placed several planter boxes down the center aisle. Filling the bottom half of each box with untreated scrap lumber, small branches, and old newspaper serves several purposes:
• It reduces the amount of high quality soil needed to fill the boxes
• It provides good drainage for plants while holding moisture to prevent roots from drying out
• It will slowly compost, adding nutrients back into the soil
• It provides food and homes to beneficial organisms living in the soil
Temperature controlled seed mats for early seed starts are on the shelving unit at the south end. Before I could afford to get the temperature controlled mats, I had to manually adjust a heating pad under the seed trays. I placed the seed trays on cookie sheets or cooling racks with a heating pad below it. Using an old thermometer, I adjusted the height of the cookie sheet throughout the day to help the soil temperature stay in the right temperature range. This was very time consuming and my husband kept trying to teach me that my time was worth more than the cost of an item (thermostat controlled mats). He was right.
I store some items, such as empty pots, under the long work shelf, but I also like to put some containers of shade loving plants under this shelf, as well.
Even in colder grow zones, having some type of shade cloth is recommended. There have been some windy days, with a foot of snow and temperatures in the mid 20s, when the temperature inside my greenhouse hit nearly 100 degrees. This still happened even though two of my six vent windows have automatic openers. The sun can very quickly bake an unshaded greenhouse.
After the rest of the inside was up and running, I began work on the cold frame over my tropical plants. Using rough-cut lumber from a local mill, I ripped and cut all the boards for framing in the structure. My greenhouse kit utilizes a sliding rail system for the bolts. I went to a local hardware store and purchased several bolts and washers of the same size but 1.5 inches longer. I predrilled holes in the studs and, using the longer bolts, I attached the boards to the vertical frame of the greenhouse wall. This gave me something solid to build on.
I could not afford to purchase the polycarbonate panels I would have liked to use this year, but I did plan for their addition as I was building the framework. After building the primary framework, I added strips across the top that will serve four purposes:
1. The wood strips create some shade when the sun is at its zenith.
2. I can tie strings or rope to the wood strips for attaching vertically growing crops such as tomatoes.
3. The wood strips provide a top shelf for storage, if needed.
4. Some strips are cut longer to hold hanging baskets.
During this past winter, as a second layer of protection, I hung a double layer of plastic around the frame. Inside the plastic covering I sat up some small aquatic grow lights, on timers, to help make up for some of the diminished daylight. I also added two heat lamps that I had hooked up to the seed mat’s temperature control unit. Since I didn’t need them to start seeds in the heart of winter, this made it possible to have a temperature-controlled environment with little effort. The heat lamps only turned on when the temperature dropped below the programmed level, and turned off when the sun came up and heated the interior.
If the cold frame had been covered with polycarbonate panels, instead of plastic sheeting, it could have handled colder temperatures. However, since this didn’t, I placed a lightweight row cover on the plants as a third layer of protection when the night temperature dropped below zero.
This year I plan to install a solar powered and temperature controlled vent fan. A great fluctuation in temperature range can stress plants and even stunt seedlings from growing properly. Managing a greenhouse isn’t as simple as just throwing some seeds into a pot and watering them, it takes work, but with proper planning, the “work” can be enjoyable.
I will be making a post, with images, of the interior raised bed build soon @ https://www.queenbee1755.com/posts/
