Houseplant Watering Schedule & Light Exposure Planner

How often to water a houseplant: how the schedule is built

The tool starts from a base interval per species and season (7 days in summer for a Monstera, 30 days in winter for succulents), then multiplies it by factors for the pot, temperature, humidity and drainage. A Monstera in a medium terracotta pot at 21 °C is given a watering every 6 days in summer.

How the interval is calculated

• Base interval (days) for the plant and the chosen season (summer or winter): from 5/8 days for Calathea or peace lily to 15/30 days for succulents.
• Multiplying factors: terracotta pot × 0.85 (porous wall), plastic or glazed ceramic × 1.15; small pot × 0.8, large pot × 1.3; room above 23 °C × 0.85, below 18 °C × 1.25; dry air × 0.9, humid air × 1.15; pot without a drainage hole × 1.3.
• The result is rounded to the day, never below 2 days, with the next watering date counted from today.

Worked examples

Monstera, summer, terracotta, medium pot, 21 °C, normal humidity: 7 × 0.85 = 5.95, so 6 days. The same in winter: 12 × 0.85 = 10.2, so 10 days. In a large plastic pot in a 17 °C room in winter: 12 × 1.15 × 1.3 × 1.25 = 22.4, so 22 days. A Calathea in a small terracotta pot at 25 °C in dry air in summer: 5 × 0.85 × 0.8 × 0.85 × 0.9 = 2.6, so 3 days.

Light and limits

• The tool compares the room's light with the plant's needs and warns in three cases: a full-sun plant without direct sun, or a bright-indirect plant placed in full sun or in a dark room. Medium-light plants never trigger a warning.
• Intervals and factors are common horticultural rules of thumb with no formal standard; the code cites no source. Always check the top 2-3 cm of soil with a finger before watering: if it is still damp, wait.
• A pot without drainage lengthens the interval to limit root rot, but standing water remains a risk.

Frequently Asked Questions

How often should I water a Monstera?

The tool uses a base of 7 days in summer and 12 in winter, giving 6 and 10 days in a medium terracotta pot at 21 °C. Water when the top 2-3 cm of soil are dry.

Should I water less in winter?

Yes: growth slows and less water evaporates. In the tool the winter interval is 1.5 to 2 times the summer one, for example 15 then 30 days for succulents.

Does a terracotta pot change how often I water?

Yes, terracotta is porous and dries faster, so the tool shortens the interval by 15%. Plastic or glazed ceramic holds water longer and lengthens it by 15%.

Can I keep a plant in a pot without a hole?

You can, but it is risky because excess water pools at the bottom and rots the roots. The tool then lengthens the interval by 30%; a drained inner pot inside a decorative cover pot is the safer option.

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.