How often, how much, and which mistakes to avoid
Most houseplants don’t die from too little water, but from too much. It sounds paradoxical, but it’s the truth every florist knows from daily experience.
Watering properly is the most important skill for any plant owner. And at the same time, the most underrated. The question “How often should I water?” has no one-size-fits-all answer — it depends on the plant, the pot, the location, and the season.
The golden rule: the finger test
Forget all watering schedules and apps. The most reliable test is also the simplest: stick your finger into the soil. If the top two to three centimetres are dry, water. If they’re still moist, wait.
This test works for 90 percent of all houseplants. Exceptions: succulents and cacti (the soil must dry out completely) and ferns/Calathea (the soil should always stay slightly moist).
How much water?
When you water, do it properly. That means giving enough water until it runs out of the drainage hole at the bottom. Then let it drain and remove any excess water from the saucer. Never leave water standing in the saucer — it leads to root rot.
Remember: It’s better to water less often but thoroughly than little and often. Frequent sips of water (only wetting the surface) cause the roots to grow only in the top layer, making the plant unstable.
Watering by season
Spring (March–May): The plants are waking up and gradually need more water. Increase watering frequency.
Summer (June–August): Highest water demand. Check daily during hot spells. Balcony plants may sometimes need checking twice a day.
Autumn (September–November): Gradually reduce watering. The plants are preparing for their dormant period.
Winter (December-February): Water much less. Plants hardly grow and evaporate less moisture. Overwatering in winter is the most common mistake.
What water should you use?
Tap water in Vienna is excellent (spring water from the Alps, soft and low in limescale). In areas with hard, lime-rich water, sensitive plants (orchids, azaleas, hydrangeas) can run into problems. Solution: collect rainwater or boil the water and let it cool.
Water temperature: Room temperature. Cold water straight from the tap shocks the roots. It is best to leave the watering can standing overnight - then the water will be at room temperature and the chlorine will have evaporated.
The most common watering mistakes
Overwatering: The number one cause of plant death. Yellow leaves, mushy stems, and a musty smell coming from the soil. Immediate action: Stop watering, let the soil dry out, and in the worst case repot the plant and cut away any rotten roots.
Leaving water in the saucer: The roots sit in water and start to rot. After 30 minutes, pour off any excess water.
Watering on a schedule: "Water every Monday" does not work. Water needs change with temperature, light, and the season. Always do the finger test.
Water the soil, not the leaves: The water needs to go into the soil, not onto the leaves. Wet leaves encourage fungal diseases, especially in African violets, begonias, and succulents.
Watering plants while on vacation
Not every plant will survive two weeks without watering. Solutions:
- Self-watering system: Clay cones or wick systems from the garden center. They work reliably for one to two weeks.
- Bathtub trick: Place the plants in the bathtub on wet towels. The plants will draw up water as needed.
- Ask the neighbors: The most reliable solution. Write a short note: "This plant every 3 days, this one every 7 days."
- Before your vacation: Water all plants thoroughly and move them out of direct sunlight (less evaporation).
Indoor plants at MoBlumen Vienna
Easy-care plants with tips from a florist.
Frequently asked questions about watering
Yellow leaves (especially the lower ones), mushy or brown stems, a musty smell from the soil, small flies (fungus gnats). At an advanced stage: black, rotten roots. The soil feels constantly wet.
Soaking is better. Place the pot in lukewarm water for 10 to 15 minutes, then let it drain well. Once a week is enough. The roots must dry out completely between soakings - which is why transparent pots are ideal.
For indoor plants, the time of day does not matter. For balcony and garden plants, morning is ideal. The plant can use the water before the midday heat arrives. Watering in the evening is also OK, but the leaves should not stay wet overnight (risk of fungus).
Order flowers from MoBlumen Vienna
Plants and bouquets - same-day delivery in Vienna.
