The primary reason to embrace bottom watering — the process of putting water below your potted plants, allowing them to soak without putting water on top — involves nasty pests. “This is perfect ...

but also grow in the wetter parts of the Southwestern U.S. These plants get their nutrition from insects they catch, and ...

Using a pyrethrin spray or aerosol labeled for gnats or flying insects gets rid of the ones flying about but has no impact on eggs and nests, Jones said.

And a tip for indoor plants: fungus gnats lay their eggs in the top few centimetres of moist soil, so make that environment inhospitable by watering from the pot's bottom instead. In permaculture ...