Growing plants in empty 2-liter soft drink (PET) bottles is totally possible! Milk jugs and other types of large food-grade plastic bottles have a variety of gardening uses too. Use them for several different types of hydroponics systems or in more traditional forms of container growing.
The cost certainly can’t be beaten. Depending on where you live, unreturned pop bottles cost 5-10 cents each. In many places, they have no deposit, which means they’re free.
1. Passive Hydroponics
This is also known as a self-watering planter, or wicking – which is how seed starter trays work with the mat under the plant cells hanging into the water tray.
It uses the same principle as Earthbox, but you need a wick. People have good results with this setup using a potting mix, vermiculite, and clay pellets.
Paint the outside of the bottom half of the bottle to hamper algae growth in your reservoir.
2. Hydro Farming
Think that recycling used bottles is reserved for home growing? Not at all. A smart farmer will look for ways to upcycle because new tools and equipment cut into farm profitability. This setup could be engineered in a greenhouse too. This grower in Brazil has a sizable operation – all based on 2-liter pop bottles and hydroponics.
3. Closed System
The screw-top element of a soda bottle also lends itself well to a closed hydroponics system plumbed with PVC pipe.
This can be small with 10 planting spots or less, and it’s also scalable to a commercial size growing operation.
Here, the nutrient reservoir is a separate container. Note that the portion of the recycled bottles used was painted on the outside. Don’t forget that roots are subterranean dwellers. They don’t want or need light. The sun is only supposed to shine on leaf and stem.
You’ll find plans to build this system here. Look at all those bottles that didn’t wind up in a landfill. They will last many years being put to the task of growing food.
4. Vertical Gardening
Whether you water by hand or hook up a pump, once again, the used pop bottle transforms into a container excellent for growing up instead of out. You can take advantage of either method inside or out.
5. Window Farms
These can work with a pump and utilize passive hydroponics too. It all depends on how you set up your system, which depends on your budget.
You can also purchase a WindowFarms system, but know that the original design began with recycled bottles. This setup uses a pump to get water to the top tier plants, and drip irrigation to all those below.
6. Indoor Greenhouse
Keeping seeds consistently moist so they will sprout is a huge challenge without the right equipment. Use the bottom half to cover the pot to keep the surface from drying out.
7. Drip Irrigation Reservoir
This works for container gardens, potted plants, and in the ground growing. The size of the bottle and your different needs will help you choose one of the above.
You can engineer the same setting using a drip catheter. You can jam a glass soda bottle full of water into a pot like these people. Or, take the easy road by suspending the bottle with a tiny hole in the lid above your planters (as seen here with recycled water bottles).
8. Plant Containers
What is the difference between the bottom part of a soda bottle and a plant pot? Drainage holes, opaqueness, and perhaps a little style.
For some types of growing, portions of soda bottles, water bottles, and beverage jugs work great. Just make sure you’ve added drainage holes first.
Updated by Catherine Sherriffs on 2020/04/02