Watering schedule

How often to water Begonia 'Passing Storm' (Begonia rex-cultorum 'Passing Storm') — the schedule

Also called passing storm begonia, rex passing storm.

More about begonia 'passing storm'

Watering at a glance

Base rhythm	When the top 2-3 cm of soil is dry, roughly every 5-7 days in growth
Spring / summer	Spring and summer: water when the top of the soil is dry to roughly a knuckle deep — typically every 5-7 days.
Autumn	Autumn: growth slows, so stretch the interval and let it dry a little more between waterings.
Winter	Winter: water noticeably less — often half as often — because low light and dormancy slow water use right down.
Light	Bright indirect light (just back from a sunny window)

About Begonia 'Passing Storm'

Begonia rex-cultorum 'Passing Storm' · also called passing storm begonia, rex passing storm · houseplant

Begonia 'Passing Storm' is a Rex-cultorum hybrid grown for dramatic foliage: dark, near-black centers and margins surrounding a swirl of silver-pink, on spiraled, asymmetric leaves. Rex begonias are foliage plants that demand bright indirect light, high humidity, warmth, and careful watering, going semi-dormant in winter. The flowers are insignificant compared with the leaves.

Ideal humidity: 50-70%

Watch for — Powdery mildew: Rex begonias are highly prone to it in still, humid air. Ensure good airflow, keep leaves dry, and remove affected foliage at the first white patches.

The watering schedule, season by season

Begonia 'Passing Storm' likes a soak-then-partly-dry rhythm — let the top of the soil dry before watering again, and never leave it standing in water. The base rhythm for begonia 'passing storm' is when the top 2-3 cm of soil is dry, roughly every 5-7 days in growth, but the real interval moves with the season, the light and the pot — so treat the figures below as a starting point and always confirm with the plant itself.

Spring & summer (active growth): Spring and summer: water when the top of the soil is dry to roughly a knuckle deep — typically every 5-7 days.
Autumn (slowing down): Autumn: growth slows, so stretch the interval and let it dry a little more between waterings.
Winter (rest / dormancy): Winter: water noticeably less — often half as often — because low light and dormancy slow water use right down.

Water around the soil, keeping leaves and crown dry, and let the surface dry slightly between drinks. Rex begonias rot easily, so avoid soggy soil and cut watering right back during winter dormancy.

Want this turned into a live reminder that adjusts to your home and the weather? The Growli watering calculator takes your pot size, light and season and returns a starting interval for begonia 'passing storm' in seconds.

How to tell begonia 'passing storm' needs water

A calendar is the worst way to water begonia 'passing storm'. Check the plant and the soil instead — for this species, look for these signals in order:

The top 2-3 cm of soil is dry to the touch (or a knuckle-deep finger test comes back dry).
Lifting the pot, it feels distinctly light.
Leaves droop slightly or lose a little of their gloss just before they truly need water.

The most reliable single check is the first one on that list. When two signals agree, water; when they disagree, wait a day and look again — under-watering begonia 'passing storm' for a day is almost always safer than over-watering it.

Overwatering vs underwatering begonia 'passing storm'

The two failure modes can look alike at a glance, so check the soil weight and wetness before you decide. For begonia 'passing storm' specifically:

Signs you are overwatering

Yellowing lower leaves and a pot that stays wet and heavy for days.
Soft, brown, mushy stems or a sour soil smell — root rot.
Fungus gnats breeding in permanently damp soil.

Signs you are underwatering

Drooping, curling leaves with crispy brown edges that perk up after watering.
The rootball shrinks away from the pot and water runs straight down the sides.
Slow growth and a generally tired, washed-out look.

Watering begonia 'passing storm' on a fixed weekly calendar regardless of season is the most common mistake — in dim winter light the same routine drowns it. Check the soil, not the date.

Water quality notes

Tap water is generally fine for begonia 'passing storm'. If your water is very hard and you see brown leaf tips, switch to filtered or rainwater.

Seasonal and environmental adjusters

Every figure above shifts with the conditions in your home. For begonia 'passing storm', the levers that matter most are:

More light and warmth speed drying; the brighter the spot, the shorter the real interval.
Pot size and material matter — small terracotta pots dry far faster than large glazed or plastic ones.
Lifting the pot to feel its weight is more reliable than any calendar for judging when to water.

Pot choice is part of this too — work out the right size with the pot size calculator, since a pot that is too big stays wet long enough to rot the roots of begonia 'passing storm'.

Begonia 'Passing Storm' watering — frequently asked questions

How often should I water begonia 'passing storm'?

Water begonia 'passing storm' when the top 2-3 cm of soil is dry, roughly every 5-7 days in growth. Spring and summer: water when the top of the soil is dry to roughly a knuckle deep — typically every 5-7 days. Winter: water noticeably less — often half as often — because low light and dormancy slow water use right down.

How do I know when begonia 'passing storm' needs water?

The top 2-3 cm of soil is dry to the touch (or a knuckle-deep finger test comes back dry). Lifting the pot, it feels distinctly light. Leaves droop slightly or lose a little of their gloss just before they truly need water. The single most reliable test for begonia 'passing storm' is the first signal on that list — checking the soil or the plant directly always beats watering by the calendar.

What does an overwatered begonia 'passing storm' look like?

Yellowing lower leaves and a pot that stays wet and heavy for days. Soft, brown, mushy stems or a sour soil smell — root rot. Fungus gnats breeding in permanently damp soil. Watering begonia 'passing storm' on a fixed weekly calendar regardless of season is the most common mistake — in dim winter light the same routine drowns it. Check the soil, not the date.

What are the signs of an underwatered begonia 'passing storm'?

Drooping, curling leaves with crispy brown edges that perk up after watering. The rootball shrinks away from the pot and water runs straight down the sides. Slow growth and a generally tired, washed-out look.

Can I use tap water on begonia 'passing storm'?