So many gardeners complain they have a hard time correctly watering their houseplants. Yet it can be so simple! Just apply the Golden Rule of Watering:
Water deeply, enough to moisten the entire root ball, then allow the soil to dry before watering again.
The Golden Rule works on 99% of indoor plants because it automatically takes into account the needs of each one. What novice gardeners don’t always understand is that the soil of each plant dries at a different speed. Therefore the potting mix of a florist’s hydrangea (Hydrangea macrophylla) may be bone dry in just 3 or 4 days, while it may take an African violet 7-8 days to reach a similar state and a cactus, 2, 3 or even 5 weeks. And the technique even takes into account the plant’s growth cycle: the same plant may need watering after 8 days in summer when it is growing rapidly, but only every 90 days during its winter dormancy. It even takes the weather into consideration: a plant will dry out more quickly when the weather is hot and sunny and the days are long, more slowly when it is cool and gray and the days are short. The Golden Rule again? It couldn’t be simpler: wait until the soil is dry to the touch, then water thoroughly.
By “dry to the touch”, I mean that you have to literally stick your finger into the mix, ideally to the second digit. If you don’t like getting your finger dirty, you can learn to weigh the pot: when soil is almost dry, it weighs much less than when it is moist. Some people are whizzes at pot-weighing! You can even go by eye: dry soil is lighter in color than moist soil. A warning though: judging watering needs by the color of the soil is most effective in the case of small plants because their root ball is smaller and dries out fairly equally. The soil in a large pot can be dry on the surface and still very wet deeper down. That’s why, for larger plants, checking with a finger or weighing the plant is more effective.
When you water, apply it slowly, letting it sink into the potting mix. Water until excess water starts to drain out through the drainage hole. Now, let the plant soak in this excess water for 15 or 20 minutes. If there is still any water left in the saucer at the end, empty it. Job done!
Some gardeners prefer to water from below rather than from above and that’s fine too. Fill the saucer with water and let the plant soak. After 15 to 20 minutes, come back and empty the surplus, if indeed there is any.
Note that you simply can’t water plants on a schedule. The “I water only once a week” gardeners will lose most of their plants over time. If you check your plants every 3 to 4 days and always apply the Golden Rule, watering only those that are dry and watering thoroughly when you do, you’ll find yourself with the greenest thumb in town!