While most people think it's neglect that does house plants in, over-watering is actually the most common way to kill your green friends. Keeping them alive means figuring out how to not drown them, and that's where charcoal comes in.
Without proper drainage, water will linger at the bottom of the pot, and roots become water-logged and susceptible to rot, fungus and bacteria. Unfortunately, when it comes to water, not all flower pots and planters are created equal. Some have drainage holes, which allow the water to seep out easily, and some don't.
If you don't have drainage holes, it's best to add a drainage layer to the bottom of your pot before adding your soil. Unlike packed soil, which traps liquid, this added layer lets it pass through quickly. Although the water is still there, it heads to the bottom of the planter, and away from plant.
Gardeners often use large loose material — like gravel or rocks — as their drainage layer. Another option is activated charcoal, or activated carbon —a highly porous material that effectively absorbs excess water. It's often used in aquariums as a filter, and to treat poison victims because of its ability to bind harmful toxins and prevent the stomach from absorbing them instead. Similarly, when added to a flower pot, it forms an effective barrier between the water and your plant's delicate roots. It's also said to remove soil impurities, deter insects, resist mold, and eliminate odors. It's especially recommended for terrariums which have a closed lid.
Note that activated charcoal is not the same as your garden-variety BBQ charcoal. You can buy activated charcoal at pet stores that sell aquarium equipment, over the counter at some pharmacies, and on-line:
- Hoffman Charcoal Soil Conditioner from Amazon; $12 for 24 ounces with free Prime shipping
- Black Gold Charcoal Soil from Amazon;$23.85 for 2 quart with free Prime shipping
- Josh's Frogs Horticultural Charcoal from Amazon; $10.98 for 1 quart plus free shipping
Have you used activated charcoal for your plants? What's your experience?