Super absorbent polymers Diaper technology for outdoor cannabis growing
Super absorbent polymers
Super absorbent polymers, or ‘water crystals’, hold 200-300 times their own weight in water. Just a few grams of powdered polymer can hold a litre of water. If you dig these water-holding gels into the ground they increase moisture content dramatically.
The main domestic application has been in children diapers/nappies where the polymer captures and holds water. But smart thinking outdoor cannabis growers, especially in hot dry climates have found ways to convert diapers into crop saving water-holding technology.
This can reduce or eliminate the need to water the cannabis plant during drought conditions. It can increase the harvest on each plant, and in the worst drought it can be the difference between survival or crop failure.
Super absorbent polymers: Sodium Polyacrylate
There are several super absorbent polymers, perhaps the most widely used is Sodium Polyacrylate which is a safe non-toxic water absorber. It is used in diapers, mixed in with cotton fibre. A very fine powdered version is used to make artificial snow.
You can buy water absorbing crystals at some garden centres or online. Many guerrilla cannabis growers prefer to buy a box of baby diapers/ nappies anonymously at the local supermarket, its easy to remove the water absorbent material from inside. And sometimes its less expensive than buying from the garden centre.
There are a couple of main theories on the best way to use water absorbent polymer crystals when growing cannabis outdoors in hot climates.
- Make a single layer (or ‘mat’) of water crystals about 40cm below the surface in a 1m x 1m pattern, or in a long trench if you are growing several plants. The idea is to keep a permanently moist layer of soil at a depth which will not be dried out by the sun. At this depth a lot of the cannabis roots will easily reach down and find water
- Other outdoor growers have a simpler approach. Dig as many water absorbent crystals as you can into the biggest hole that you can be bothered to dig. With enough water crystals hundreds of litres of water holding capacity can be added, allowing much larger plants to be grown. And helping to protect the plant for longer periods without rain.
To remove the water absorbing gel from a diaper simply cut it open with a pair of scissors and shake free the dry gel. The video shows how its done.
Gel can dry out & rehydrate many times
The gel can dry out and rehydrate many times. This means each good rain storm will allow the water absorbent crystals to regrow. Normally growers prefer to add the crystals to the soil when they are fully hydrated, this means that the plant starts life with a ‘fully charged’ level of maximum water.
Traditional agriculture is starting to use more and more of the water absorbing polymer crystals, however not all farmers are convinced that it is cost effective when growing ‘low value’ crops such as salad and vegetables. Using the water crystals costs around $1.5 per square metre, and they expect the crystals to last for 5 years.
Cannabis growers will not worry about the cost of a few extra Dollars/Euros spent on water gel. Its is a small investment compared to the value of the eventual cannabis harvest. Most outdoor cannabis growers invest a great deal of time in a small number of plants that are intended to provide a years worth or medical/recreational cannabis.
Supermarkets use water crystals
Supermarkets already use the water crystals to increase the ‘shelf life’ of small ornamental and garden plants. Many fruit/vegetable farmers in hot climates are looking to see if water absorbent polymer technology can help increase drought-resistance of their crops and increase the productivity of farm land.
More and more outdoor cannabis growers are using water absorbent gel to increase the chances of their plants making it through hot, dry summers. All it takes is a box of nappies and a little bit of digging and you could be increasing the amount of harvest from your own outdoor garden.