Earlier this week, we dedicated a lot of time to greenhouse insulation and heating. But, that’s a reality that’s not in the cards for everyone, either due to cost or other constraints.
So, let’s bring back this blast from the past! Before we had a full size greenhouse, our strategy was to use small, seedling sized mini greenhouses to get our plants outside! These can easily be built for far less than $100, even these days!
This was our final evolution, custom built to our preferred size out of PVC and UV rated plastic. Before this, we hacked together those crummy shelf based greenhouses, but ultimately abandoned them as they barely last a season or two.
The frame is built from 1-1/4″ PVC. There’s many fittings out there, designed to connect PVC in all sorts of ways. The UV plastic is connected to the frame with clamps. We’d remove the plastic at the end of the season, just to keep it protected.
The design is wholly flexible, practically whatever you can dream up. Our design goal was “tall enough” to fit our tallest seedlings, plus the ability to fit about seven 1020 trays and a heater.
The beauty of smaller systems like this is they take very little energy to keep them above freezing. Just like with our larger greenhouse, you can use a small heater and a temperature controller to hold conditions at frost-free and relatively cost effective temperatures.
Also like our greenhouse, you can run smaller DIY greenhouses like this against freezing temperatures and even light snowfall. The goal is to get your plants under the sun, while simultaneously protecting them from frost.
The drawback to these seedling greenhouses is they require a lot of manual intervention. It’s critical to at least crack the greenhouse during the day, otherwise your plants can easily cook. Some days, we’d remove it off our seedlings entirely.
And, in case you want a bit more info, we have a full write up from our “early days” that describes the technique in more detail. Link in the comments! If a full size greenhouse isn’t for you, maybe something like this can be?
