Plastic Bottle Cold Frames and Greenhouses

The plastic bottle cold frame on display at the Lewis County Home and Garden show

Recently, V. took me to the Lewis County Home and Garden show.  The event was basically a total bust–just a bunch of roofers trying to drum up business, really–but the one highlight was the booth for the WSU Lewis County Master Gardeners and Composters program.  In addition to a lot of great information, amazing people, and beautiful plants, they also features a few DIY garden project ideas, and the one that impressed me the most was their cold frames and greenhouses made of scrap lumber and thousands of plastic bottles!  The picture above is one I took of their sample cold frame, which I thought looked pretty attractive. (Though they should have removed the labels from all the bottles.)  Both the top of the frame and its front side opened up to allow for easy access to the growing vegetables within, which I thought was wonderful.   One of the gardeners staffing the booth said that he had used a few over the past growing season and found that they did help raise the temperature around the vegetables a few degrees, and he liked the fact that there were enough holes and spaces around the bottles that he didn’t have to worry about humidity building up and causing mold.  The spaces also let a good bit of natural rain through, though you do have to augment with manual watering.

I doubt that either V. or I will be building one of these anytime soon, since we don’t have an abundance of plastic bottles.  If I worked at a place where I noticed many other people drinking from disposable plastic bottles, I think I would ask them if I could collect them for this project.  If V. gets really enthusiastic about this project, I might go knocking on our neighbors doors and ask if they hold these bottles out of their recycling for us.  Somehow, I think it would be a lot better for everyone involved if we plastic-reducers re-purposed other people’s bottles rather than developing our own soda or juice habits!

The good gardeners sent me on my way with an instructive brochure with rough plans for this cold frame construction, and I’ve made it into a .pdf that you can access here.

A bottle greenhouse!

Of course, the same basic techniques used to create this cold frame can also be scaled up to create an entire greenhouse!  This particular greenhouse constructor managed to source 7,000 identical 1.5 liter water bottles from his friends, and he used clear silicone to adhere the bottles to each other to make solid panels without ‘stringing’ the bottles onto strips of wood.  This means that this particular greenhouse is fully sealed, so allotments will have to be made to control humidity.  However, I think he ended up creating a very handsome greenhouse for his trouble!