I had been wanting to upgrade my coldbag, because even it works really nice, the little seedlings could have even more advantages. In particular I wanted something that would let more sun to the little seedlings.
So I started scavenging for materials to use. I didn't wanted to build one out of wood and glass, because my goal was keeping the portability and cheapness of the cold bag. I considered using a cardboard box, but I knew that on the first rain, or with the water pouring out from the little started planter, I would end up with a cold frame soup in no time.
Then I remembered that here, at some grocery stores, they always leave all the plastic boxes from the food, all cleaned and ready for people who need them to pick them up. So, one day I went grocery shopping, I took a small look at their little recycle corner. There I found the perfect box. It was a deep, thick expanded polystyrene box, in perfect condition.
The build was very simple.
I used two plastic sheets, one in each side of the cover. That way the insulation will be much better. The air in the middle will work as the insulator. The same way a double glass (double frame) windows work better than a single glass window.
So far it has worked beautifully. The little seedlings growing there sprouted in no time, they have even reached the size of the ones in the coldbag already.
The first to grow were the Bekana and the Komatsuna, then the spinach and finally the lettuce, coriander and the chives. I was surprised the chives and the lettuce sprouted, they are supposed the be past their season. They must really be very cozy and warm in there. I hope they all keep growing nicely, I will post more about how they develop later.
Now, the only setback is that the new coldframe has such a good insulation that every morning the inside screen appears all damped because of the condensation. I have to dry it a bit and clean it up so it will let the sunshine in.
I recommend anybody who wants to have a nice cheap planter at their homes to use old expanded polystyrene boxes. First, because is much better to reuse them than throw them to the garbage. Second because they are great planters. Expanded polystyrene is a great ecofriendly material, even though it certainly doesn’t look like it. It is a great insulator, and has an amazing endurance for such a light weight. It definitely won't mold and It will not degrade easily, so I can last lots of gardening seasons.
One more thing about polystyrene. It is highly recyclable, but it very hard to do it because it has to be sorted away from other materials, which is a very troublesome task. This causes a big problem because it is usually thrown with normal garbage and pollute instead of being recycled. So, if you can rescue some polystyrene from going to the dumpster, and give it some more years of use please do.
The new seedlings are doing great
So I started scavenging for materials to use. I didn't wanted to build one out of wood and glass, because my goal was keeping the portability and cheapness of the cold bag. I considered using a cardboard box, but I knew that on the first rain, or with the water pouring out from the little started planter, I would end up with a cold frame soup in no time.
Then I remembered that here, at some grocery stores, they always leave all the plastic boxes from the food, all cleaned and ready for people who need them to pick them up. So, one day I went grocery shopping, I took a small look at their little recycle corner. There I found the perfect box. It was a deep, thick expanded polystyrene box, in perfect condition.
Building the new coldframe
The build was very simple.
- I carved a small window on the cover of the box to leave only a frame. Being sure to leave a small edge
- Cut apart a transparent plastic bag to have two sheets to use as "glass".
- I taped one of the transparent sheets to the edge I had left and cover the hole in the frame.
- Turn around the lid and tape the other sheet from the inside. This will make the window a sandwich of plastic, air and plastic.
- Finally use little pieces of tape to cover any hole in the borders. The more airtight the better
I used two plastic sheets, one in each side of the cover. That way the insulation will be much better. The air in the middle will work as the insulator. The same way a double glass (double frame) windows work better than a single glass window.
So far it has worked beautifully. The little seedlings growing there sprouted in no time, they have even reached the size of the ones in the coldbag already.
From back to front: Bekkana, Spinach, Komatsuna, Lettuce
The first to grow were the Bekana and the Komatsuna, then the spinach and finally the lettuce, coriander and the chives. I was surprised the chives and the lettuce sprouted, they are supposed the be past their season. They must really be very cozy and warm in there. I hope they all keep growing nicely, I will post more about how they develop later.
Now, the only setback is that the new coldframe has such a good insulation that every morning the inside screen appears all damped because of the condensation. I have to dry it a bit and clean it up so it will let the sunshine in.
I recommend anybody who wants to have a nice cheap planter at their homes to use old expanded polystyrene boxes. First, because is much better to reuse them than throw them to the garbage. Second because they are great planters. Expanded polystyrene is a great ecofriendly material, even though it certainly doesn’t look like it. It is a great insulator, and has an amazing endurance for such a light weight. It definitely won't mold and It will not degrade easily, so I can last lots of gardening seasons.
The first seedlings sprouted in 4 days
One more thing about polystyrene. It is highly recyclable, but it very hard to do it because it has to be sorted away from other materials, which is a very troublesome task. This causes a big problem because it is usually thrown with normal garbage and pollute instead of being recycled. So, if you can rescue some polystyrene from going to the dumpster, and give it some more years of use please do.
