paper mache' stuffed wet into the gaps...problem solved hoo ray.

These are way better than drums filled with water, but who knows if they really work? I fill the jugs with water, then add some concentrated black fabric dye. The sun passes into the water for direct heating. They also last a year or two. I also put some mud in cracks at the eave and that is still tight a year later.

here are some collectors from last year; still have them in place.

Just found this "aerial" photo of my greenhouse creation. Actually two totally different designs connected. I believe they may be the only greenhouses in the state that can operate all summer with no electricity and no shade cloth.

Loved seeing your pics Sand. We recently burned (hated to, but it had disintegrated too much to stuff it all into a garbage bag) a large 25x50 piece of plastic sheeting that we used for two summers to solarize part of the garden. We have also decided not to use it ever again. We've been accumulating cardboard boxes to use for mulch under wood chips. It won't solarize but it will mulch and rot into the ground eventually.

I use all kinds of bottles as solar collectors and think it does make a difference in the greenhouse. I've also got Aluminet shade cloth (50%) on the greenhouse and leave it on all winter as it helps hold in the heat inside the greenhouse. In the past I used large molasses feed tubs as solar collectors, and I still have a few of them, but most of the molasses feed tubs now are out in the garden filled with soil and used to grow plants. There's still a few molasses feed tubs filled with water on the south side of the greenhouse, but most of my solar collectors are Tidy Cat cat litter buckets (I like that I can stack them on top of one another), cat litter jugs, milk cartons and 2-liter bottles. I have an exceptionally high number of those in my greenhouse, which is covered with a soft shell of 6 mm greenhouse plastic, and they really do keep it warmer. Even on a cold night with low temps in the teens, the greenhouse only drops down to 30-32 degrees. We have to go into the single digits, or have highs only in the 20s or 30s and heavy clouds, in order for my greenhouse to drop much below freezing. As long as we have a reasonable amount of sunshine, the solar collectors do a great job of keeping the greenhouse warm. I used them before we bought the Aluminet shade cloth and they didn't work as well then as they seem to now, so I think the best combination for my particular greenhouse is to have the Aluminet plus tons of solar collectors filled with water.

I love using cardboard, Dorothy, but the earthworms here devour it incredibly fast, so I often put 2 thick layers, or even more thin layers of the thinner types of cardboard, on the ground beneath mulch, and the cardboard still totally disappears in just a couple of months. Luckily, by the time the cardboard has disappeared, I've got enough mulch on those areas to keep weeds from sprouting.