I have a tunnel house (for edibles) and Julie has a glasshouse (for her ornamentals) – she’s a fancy one! 

Despite these forms of “protection from frost” they can get to low temperatures on cold winters morning. We’ve seen 1.5 degrees a few times. 

Is there a way to add some extra insulation to these buildings that would keep the temps a bit higher? 

As per usual: my local Botanic Garden has delivered some answers (see pictures); the “Curators Garden”, an edible garden next to the Curators House restaurant, here in Christchurch, always investigates new ideas and technologies. 

(No doubt your local Botanic Garden will have some great ideas as well!) 

Wouldn’t it be great to have a temporary layer of insulation for just the winter months – stuff you can remove when spring starts? 

I love the idea of having old, recycled plastic drink bottles assembled vertically on a long bamboo pole. Each pole can be removed in its entirety and stored for re-use next winter.

 

Honey-comb plastic screwed between two pieces of wood to tighten them up. It’s almost a double-glazing system made from plastic. It lets sun through and blocks the cold. 

It, too, can be removed in its entirety for storage during spring and summer 

Bottles stacked horizontally and filled with water are probably more efficient at insulating the air inside the glasshouse. 

These is old Bubble-wrap that can be used on vertical walls and Perspex sheets that can be fixed to the ceiling on the inside of the glasshouse too. 

By “retro-fitting” double glazing you don’t lose any space inside, really, but keep the cold from coming in to slow all growth