Bearded iris: leaves yellowing and flopping after flowering

What it is likely to be on bearded iris

1. Natural summer dormancy

   May be normalvery common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Cyclamen hederifolium — cultivation
   • Plant Finder — Missouri Botanical Garden: Cyclamen hederifolium

   Checked 2026-08-13

   A plant that yellows, collapses and disappears in midsummer because that is its year. Woodland and Mediterranean geophytes finish growing when the canopy closes or the soil dries, and they spend the summer underground as a perfectly healthy tuber — which looks exactly like a plant that has just been killed.

   Points towards it

   • · the whole plant goes down together, evenly, because the whole plant is finishing
   • · nothing was done to it — this is the plant's own calendar rather than an event
   • · the seasonal cycle of a garden geophyte

   Argues against it

   • · spotting or mould on the dying foliage is a disease taking the leaves early, not the plant putting them away — this rules it out entirely.
   • · part of a clump dying while the rest stays green is not a seasonal cycle — a season applies to all of it — this rules it out entirely.

   Check this next

   Scrape a little soil away and feel for the tuber or bulb. A firm one under vanished foliage in midsummer is a dormant plant in perfect health; a soft, light or absent one is a different answer entirely, and the check takes ten seconds against waiting until autumn to find out.

   What to do now

   Stop watering it and mark where it is so nothing gets planted on top. A dormant tuber rots if it is kept wet through the summer, which makes watering — the first thing most people do — the one genuinely harmful response to this diagnosis.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Cyclamen hederifolium — cultivation

   Checked 2026-08-13

2. Overwatering

   Candidate 2common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Cyclamen hederifolium — cultivation
   • Royal Horticultural Society: Iris rhizome rot

   Checked 2026-08-13

   Not a matter of volume but of frequency: roots need air as well as water, and compost that never dries suffocates them. It kills more houseplants than every pest and disease combined, and its cruellest feature is that the early signs — yellowing, wilting, dropping leaves — look exactly like drought, so the instinct is to water more.

   Points towards it

   • · the ground is wet at exactly the season these plants need it dry, which is the one condition that turns a dormant tuber or rhizome into a rotten one
   • · nothing changed except the weather or the watering can, and a summer of both is what does it

   Argues against it

   • · dry ground in summer is what both of these plants want, and it is the condition under which the yellowing is simply dormancy — this rules it out entirely.

   Check this next

   Feel the ground rather than the plant. Dry soil over a vanished cyclamen in July is the plant resting; ground that has been kept damp all summer, or a bearded iris rhizome sitting under wet mulch, is the version that rots — and a rhizome that has gone soft and sour-smelling settles it at once.

   What to do now

   Stop watering and keep summer mulch off the crown, and move a pot somewhere it will not be rained on until autumn. Scrape the soil back from a bearded iris so the top of the rhizome is exposed to the sun, which is where it is meant to be.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Iris rhizome rot — prevention

   Checked 2026-08-13

Narrow it down

This page lists everything at once, which is the right shape for reading and the wrong shape for deciding. The interactive tool asks one question at a time, starting with whichever would separate these causes fastest, and stops as soon as further answers would not help.

Opens with the plant and the symptom already set. Nothing you answer is stored or sent anywhere — the answers live in the address bar and nowhere else.

What this does not cover

These are the causes GrowingHQ holds rules for on bearded iris — not every cause there is. Where several problems look alike, the honest answer is often that they cannot be told apart by eye, and a page that named one would be guessing. If none of the above fits, the general leaves yellowing and flopping after flowering page lists causes across all plants, and the Bearded iris profile lists the problems it is prone to.