Water hyacinth care guide
Pontederia crassipes
Also known as: Hoteisou, Eichhornia crassipes
Pets and children
We haven't been able to confirm how this plant affects pets or small children. If any is eaten, consult a veterinarian or a doctor.
How often to water Water hyacinth
- Spring–Summer (Mar–Sep)
- Every 3 days
- Read watering as topping up: about every two to three days in summer, replace what has evaporated and swap part of the water when it gets dirty.
- Autumn (Oct–Nov)
- Every 7 days
- Evaporation slows, so top up about once a week and remove dead leaves and roots as they appear.
- Winter (Dec–Feb)
- Every 14 days
- If it winters indoors, top up about every two weeks; a plant left outdoors generally dies.
Light and placement for Water hyacinth
As a guide, a water bowl or tub outdoors in full sun; short of light it generally stays small and will not flower, and in midsummer a deeper container keeps the water from overheating.
Overwintering Water hyacinth
Overwintering guide: 5°C (41°F) or above
Tender and killed by frost, so it is generally treated as an annual; to keep one, as a guide bring a small plant indoors in its water to a bright window when nights fall below 10°C and hold it above 5°C.
Fertilizing and repotting Water hyacinth
Fertilizer
It generally needs no fertilizer, living on nutrients in the water, especially with fish such as medaka; only if it will not flower, add a tiny amount of aquatic-plant fertilizer as a guide.
When to repot
Spring–Summer (Mar–Sep)
Common problems with Water hyacinth
- Too little sun means no flowers and pale leaves.
- Left outside into winter, it dies in the frost.
- It multiplies until it covers the surface and the fish run short of oxygen.
Tips for growing Water hyacinth
- It is invasive: dry and discard extra plants rather than releasing them into a river or pond.
- Keeping about half the surface open keeps both the water and the plants healthy.
- Each flower lasts about a day; cut the spent stalk before it rots in the water.
These are AI-generated general guidelines. They vary with the variety, the placement and the pot size. For effects on pets or children, consult a veterinarian or a doctor.
Keep your plant log going
Greenery is a free app that keeps your plant care going, with watering reminders and photo records. Available on iOS and Android.
