Mini-greenhouses or coldframes - not sure what to call them

First post in a while. I've been so busy with work and travel that I haven't had any time to spend in the garden. Maybe that's why it's been so sucky lately??

Anyway...

Dedicated readers (if there are any) may remember that last year, I put together a makeshift, greenhouse-like structure out of old fencing, some fenceposts, and some plastic tarps. Rather than go down that same path this year, I decided to build a mini-greenhouse for each of my grow tubs.

 First, I built a wooden frame around the grow bed. Not as easy as it sounds, even though all the grow beds are the same product. They each seem to sag in a different way, so each of the frames had slightly different dimensions and different heights.

 

Next, I created a PVC greenhouse using mostly existing 1/2" PVC that I had from other experiments uses. I bought special 45 degree elbows and special 3-way fittings for the bottom corners from a greenhouse supply store.

  

Once the PVC frames were done, I used my old plastic that I used last year. I basically rolled the frame in the plastic, then used plastic clips to hold the clear/opaque plastic to the PVC frame. Each greenhouse has 2 little chimneys that I'm hoping will help it from getting too hot in there. Though the plastic drapes down the sides, it's certainly not air tight, so there should be some air flow, even when the sides are fully down.

 

 Here's a view through all 3 greenhouses. I rolled up the sides to keep air moving through there. I probably will keep it rolled up until it gets closer to 25 degrees at night. 

The cilantro, arugula, and spinach that I've planted, along with the tub full of strawberry plants, proved last year that they can handle the cold. The greenhouses should help warm things up during the day nicely, and they'll keep the frost off of the plants at night. Another side benefit is that they keep the leaves from landing on the grow beds! This time of year, it's a daily chore picking the leaves out.

I put in another order for rainbow trout this year. It went so well last year, I figured we'd do it again this year!

Indoor experiment over

We decided that we didn't like having the system inside. Two main reasons: 1) it was partially blocking access to our sliding glass door, and 2) we were concerned about the weight of the system on our 100 year old floor joists.

In addition, we didn't have proper grow lights, and the plants didn't seem to be fairing very well.

So, it's a chance to do some things I should have done in the first place: put a couple of coats of poly on the wood to make it waterproof and have it be able to be used outdoors, and build new grow beds with more appropriate sizing for the system.

We're trying to sell our car, and if successful, we may use some of that money to get a small greenhouse (8' X 8'). If that happens, it will be the perfect size for this system, and we'll get a small propane heater and run the small system in the greenhouse with tilapia.

My permit for tilapia should come any day now. The Wildlife Resource Commission folks came to inspect my property a week ago and didn't see any reason why my permit would be denied.

Quick Update

Weather has warmed up a little, and we had a couple of near 60 degree days. Both the trout and the veggies like things a little warmer than what it had been. Broccoli is still growing. I lost a few, though. Their trunks would sometimes get squishy in the middle in a 2-4 inch section, while everything else looked OK.

I think that if I was able to maintain a temperature inside my "greenhouse" of 30 degrees during those colder nights, I think they would be fine. This little experiment has given me a lot of hope for winter-time aquaponics with an outdoor pond. I don't think it would be too expensive to have a small greenhouse and a little heater of some sort that would be capable of keeping the air temp around 30 degrees. Day time heating on sunny days, would, of course, raise the temps in there greatly. It's just those cold nights and cold/cloudy days where you have to worry.

The trout are still very shy in sight and sound, but it's not a big deal to stand a little bit away and toss the food in from a distance. I've also noticed that, at night, they are afraid of normal flashlights, but seem unconcerned about LED lights. That got me to thinking that it would have been cool to have installed an underwater LED light in my pond for night time. The fish don't seem to notice the light at all. If they do notice it, they certainly don't seem to be afraid of it.

Rainbow Trout and a Snow Camp Greenhouse

30 rainbow trout arrived on Friday all in the 6-9" range. A couple of them seemed pretty frazzled from the delivery and introduction into the pond, and I found one dead Sunday morning (tasted delicious!). Other than that, they seem to be doing very well. They haven't been eating all that much, though this morning, they seemed to be quite active, despite the sub-30 degree outside temperatures. I think the timing of feeding may be important with them. On Sunday, I tried feeding them around 9 AM, and there wasn't much interest. This morning, I fed before work at around 6:30, just as the sun was coming up. It's generally a good time to fish, so I guess it makes sense.

In addition, I created what I'm calling a Snow Camp greenhouse (because it is so ghetto!). I just used some extra fencing to create a tunnel shell over the two buckets with taller plants and then draped some 6 mil plastic over the top, tied it all down so it wouldn't blow away, and called it a day. Is it any warmer in there that the outside? Probably not! But, at least it'll keep the hard frost off of the plants (spinach, bok choi, broccoli, cilantro, and arugula). I found some nice tutorials about making a greenhouse on the cheap with a PVC-based tunnel shell and 6 mil plastic, but the 20X100' roll of 6 mil plastic is $90+ just by itself! If I'm gonna spend more than $150 on a greenhouse, I might as well do it right. And since we're hoping to move soon, it just made sense to use what I had around and make the best out of it. Hopefully it's good enough!