0How it thrives
Waterhigh
Lightfull sun
Humiditylow
Min. temperature-30 °CJanuary
Only very rarely, a little water so the roots don’t dry out completely.
No feeding now.
It can stay outside. Wrap the pot (hessian, polystyrene) and keep it against the house wall, out of the rain.
February
Only very rarely, a little water so the roots don’t dry out completely.
No feeding now.
It can stay outside. Wrap the pot (hessian, polystyrene) and keep it against the house wall, out of the rain.
March
Gentle start: the first small drink once you see buds or new growth and it warms up.
First weak dose at the end of the month if it is actively growing.
The sunniest window (south or west).
Move it somewhere brighter and warmer and end wintering. Get it used to strong sun gradually.
April
Keep evenly moist but never waterlogged.
Liquid feed every 2–3 weeks.
The sunniest window (south or west).
It flowers next month – once you see buds, don’t move it any more.
May
Keep evenly moist but never waterlogged.
Liquid feed every 2–3 weeks.
Best outdoors: sunny balcony, terrace or garden – acclimatise it to full sun gradually.
It usually flowers now – don’t turn or move it, and log the bloom in your diary!
June
Keep evenly moist but never waterlogged – more often in heatwaves, preferably in the evening.
Liquid feed every 2–3 weeks.
Best outdoors: sunny balcony, terrace or garden – acclimatise it to full sun gradually.
It usually flowers now – don’t turn or move it, and log the bloom in your diary!
Above 35 °C, shade it at midday to prevent sunburn.
July
Keep evenly moist but never waterlogged – more often in heatwaves, preferably in the evening.
Liquid feed every 2–3 weeks.
Best outdoors: sunny balcony, terrace or garden – acclimatise it to full sun gradually.
Above 35 °C, shade it at midday to prevent sunburn.
August
Keep evenly moist but never waterlogged – more often in heatwaves, preferably in the evening.
Liquid feed every 2–3 weeks.
Best outdoors: sunny balcony, terrace or garden – acclimatise it to full sun gradually.
Above 35 °C, shade it at midday to prevent sunburn.
September
Keep evenly moist but never waterlogged.
No feeding now.
Best outdoors: sunny balcony, terrace or garden – acclimatise it to full sun gradually.
October
Taper off gradually: very little by the end of the month.
No feeding now.
The sunniest window (south or west).
Move it to its cool, bright winter spot and taper off watering. Log it with one click in the Care hub.
November · now
Only very rarely, a little water so the roots don’t dry out completely.
No feeding now.
It can stay outside. Wrap the pot (hessian, polystyrene) and keep it against the house wall, out of the rain.
December
Only very rarely, a little water so the roots don’t dry out completely.
No feeding now.
It can stay outside. Wrap the pot (hessian, polystyrene) and keep it against the house wall, out of the rain.
Leave bearded iris rhizomes half above ground so the sun can bake them.
Yellow flag – what to know
Yellow flag (Iris pseudacorus) belongs to the Iridaceae family (genus Iris) and is listed in our catalog under “Garden flower”. Its needs – light: full sun; water: high; humidity: low. Frost-hardy to about -30 °C – it can overwinter outdoors in many climates. Rest period: cold winter dormancy. Typical flowering time: May, June. Easy enough for beginners. For cats: mildly toxic; for dogs: mildly toxic. Keep it out of reach and call a vet straight away if you suspect poisoning. Nobody on Perfect Plants Club has added it to their collection yet – be the first!
Frequently asked questions
How often should I water Yellow flag?
Generously: keep the soil evenly moist and never let it dry out completely.
How much light does Yellow flag need?
It needs plenty of direct sun – the sunniest window, or outdoors in summer, suits it best.
How cold can Yellow flag get?
Frost-hardy to about -30 °C – it can overwinter outdoors in many climates.
Is Yellow flag toxic to cats and dogs?
For cats: mildly toxic; for dogs: mildly toxic. Keep it out of reach and call a vet straight away if you suspect poisoning.
When does Yellow flag flower?
Typical flowering time: May, June.
What members’ data shows
When does it really bloom?
No blooms logged yet. If yours flowers, your data will be the first!
Average watering interval
Not enough watering logs yet. Waterings logged in the care hub feed this chart.
Tips and questions about this species
Iris
Care data is for guidance only.
Log in to comment.