• Root Houseplants

Overwatering by James Freeman

Right now, someone somewhere is fatally overwatering a houseplant. I can almost hear screams of “put the watering can down”. Elsewhere the drama continues, a benevolent house sitter has dangerously promoted themselves to Director of Watering and without hesitation, has commenced waterboarding an innocent cactus. These are regular scenes in the brutal world of watering.

So what is overwatering?

Overwatering occurs when our houseplants end up with their roots submerged in water and all the tiny air pockets in the soil fill with water. This stops the delicate root hairs from absorbing oxygen until either the water eventually drains away, the soil dries out, or in some extreme cases, the water will need to be poured back out.

Overwatering usually occurs when poor old mass-produced-ugly-black plastic pots are put inside more decorative pots, or if they have been planted up in a container with minimal or no drainage. It can also be quite easy to do, and if you are watering your plants regularly where they are it’s easy to overwater them. I find taking the plant to the altar of watering (the sink) helps ensure that you’re not absent mindedly guessing how much water to pour in. Another symptom of overwatering is root rot. This will stymy growth or worse, kill the plant. Wet top soil is also a favourable home to gnats and tiny annoying flies.

Keys to prevent overwatering

  • As a general rule let the top few centimeters dry out completely before watering

  • Don’t water the plant in situ, taking the plant to water allows for quality observation time

  • Observation is key, maybe even keep a plant watering journal

  • Make sure you have free draining soil and a pot with adequate drainage

  • Get used to knowing how heavy a well watered plant feels vs bone dry, if the pot is still heavy leave it a few more days

  • As a good rule of thumb, completely soak the soil in the pot, allow any excess to drain out into the sink/shower/tub

  • Instead of watering from above, stand the pot in 5cm of water for half an hour. This allows the soil to absorb only the amount of water in can handle

I’d like to point out that despite studying plants, I inadvertently follow quite a strict regime of total plant neglect with varying results. I may be one cactus down from last week but everything else is growing well and looking healthy. I mist my plant’s leaves regularly and when I remember to get watering, I use tap water and the soaking in the sink method, it works for me. If you can use rainwater instead that’ll be even better. The real secret is knowing your plant’s needs and keeping a keen eye out for signs of plant stress. I like to experiment with my watering techniques, when I remember, and I suggest we all do. Each plant and the environment it’s in will differ, especially with the on set of winter looming.

Before I leave you, last week I experimented on an unwitting Chlorophytum comosum (spider plant). I was boiling beetroots and had decided I’d use the cooled water to soak the old gal. After a few days the leaves have never been so green and the whole plant looks healthier than ever.