Rosemary: lower leaves turning yellow

What it is likely to be on rosemary

1. Overwatering

   Candidate 1very common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Rosemary — cultivation

   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

   • · rosemary evolved on free-draining hillsides and its roots rot in ground that stays cold and wet through winter
   • · failing roots take the whole bush down rather than one branch
   • · it typically shows in late winter and early spring, after months of wet rather than after any single event

   Argues against it

   • · the soil is dry, so the roots are not drowning — and rosemary tolerates drought far better than any other state — this rules it out entirely.

   Check this next

   Take hold of the base of the plant and rock it, then look at the soil it is standing in. A rosemary killed by winter wet moves loosely in the ground because the roots have gone, and the yellowing runs up whole branches to a grey-brown tip — the diagnosis is about the DRAINAGE rather than about the frost that usually gets blamed, and a plant on a slope beside a dead one in a hollow tells you which it was.

   What to do now

   Stop watering and do not feed it. Where it is in a pot, tip it out, cut away any black soft roots and repot into a gritty mix with a third sharp sand. In the ground the durable answer is to replant on a raised mound or a gravelly bank rather than to improve the planting hole, because a hole of good soil in clay is a sump.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Rosemary — cultivation

   Checked 2026-08-13

2. Normal leaf ageing

   May be normalcommon on this plant

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Rosemary — cultivation

   Checked 2026-08-13

   Not a problem, and included as a candidate because it is one of the commonest explanations for a single yellow leaf on an otherwise healthy plant. Every plant sheds its oldest leaves; a differential that cannot return 'nothing is wrong' will always find something to blame.

   Points towards it

   • · an evergreen sheds its oldest leaves continuously, and on rosemary those are the ones nearest the woody centre
   • · it is confined to the shaded inside of the bush while the tips grow away
   • · nothing changed, which fits a continuous background process

   Argues against it

   • · whole branches yellowing to the tip is not interior shedding — that reaches only the oldest leaves in the middle — this rules it out entirely.
   • · wet ground under a rosemary makes root failure a much better explanation than ordinary leaf turnover

   Check this next

   Look along a single branch from the tip towards the middle of the bush. Evergreens replace their leaves on a rolling basis rather than all at once, so a rosemary with fresh grey-green growth at every tip and a scatter of yellow needles deep inside — the ones that get no light — is turning over normally, and the shedding stops where the light starts.

   What to do now

   Brush the loose needles out of the middle of the plant and leave it be. Trim the tips lightly after flowering to keep it bushy, but never cut back into the bare wood at the centre — rosemary does not reliably reshoot from old wood, and a hard cut is how a tired but living plant is finished off.

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Pruning herbs

   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 rosemary — 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 lower leaves turning yellow page lists causes across all plants, and the Rosemary profile lists the problems it is prone to.