How often should I water houseplants?

Most common houseplants want watering when the top inch of soil is dry, usually weekly in summer, every 10-14 days in winter. Stick your finger in the soil; if it's dry an inch down, water. Wet down an inch, wait. Schedules are less reliable than feel.

What's wrong with using a regular watering can?

Nothing for floor plants. The problems start with hanging plants (water spills, you can't see the spout), tall pots (the can tips before reaching the soil), and tight spots (the spout is too thick). A narrow-spout squeeze bottle solves all three.

Should I water from the top or bottom?

Top watering is faster and gets water to the root zone immediately. Bottom watering (placing the pot in a tray of water) is slower but reduces the risk of overwatering and is better for plants that don't like wet leaves (succulents, African violets).

What temperature water?

Room temperature for indoor plants. Cold tap water shocks tropical houseplants; let it sit for an hour before using. Outdoor plants are tougher and don't mind.

Is collected rainwater better than tap water?

Marginally, for most plants. Tap water with chlorine is fine; letting it sit overnight evaporates most of the chlorine if you're worried. Some plants (carnivorous plants, calathea, sensitive ferns) prefer rainwater or distilled water. For most houseplants, tap water is fine.

Plant watering 101: tools for hanging plants and hard-to-reach spots