Why Rosemary Turns Brown in March – and How to Save It

Many rosemary bushes look miserable in March: brown tips, dried-out needles and apparently dead wood – but this is often far from a death sentence.

Reaching for the secateurs in a rush, or even removing the plant altogether, will usually make matters worse. What matters more than winter itself is how you treat your rosemary in early spring. A few straightforward steps can revive browned plants, encourage fresh growth and keep the shrub in a border or container for many more years.

Why rosemary suddenly turns brown in March

Rosemary originates from the Mediterranean, where it experiences cool nights but not a combination of prolonged frost, saturated soil, strong winds and bright winter sunshine. In the UK and similar climates, this exact mix puts the plant under strain.

Common reasons for brown shoots in late winter include:

• Frost drought: The soil is frozen, so the roots cannot take up water, while wind and sunshine draw moisture from the needles.
• Waterlogging: This is particularly common in pots, where water can collect and cause root rot; the upper part of the plant then dries out.
• Winter sun followed by night frost: Shoots thaw during the day before freezing hard again overnight. Cells burst and the needles turn brown.
• Incorrect autumn feeding: Soft growth produced after late feeding does not ripen properly and is far more likely to be killed by frost.
• A sensitive variety: Some rosemary varieties cope with sub-zero temperatures much less successfully than others.

Brown needles in March are often a sign of stress – not proof that the rosemary is dead.

For many plants, looking unattractive in late winter is almost part of their normal annual cycle. It only becomes a serious concern when the wood itself has been damaged.

How to tell whether your rosemary can still be saved

Before cutting anything back, make a proper assessment. Needle colour alone is not enough; the condition of the shoots and bark is more important.

Typical signs of genuine frost damage

• Shoots appear translucent, soft or greyish brown.
• The bark comes away when lightly rubbed with a fingernail.
• There is no green visible inside the twig, only brown or black tissue.
• Needles drop off with minimal touching or shaking.

What still-living rosemary looks like

• The needles may be brown, but they remain firmly attached to the shoot.
• A light scratch beneath the bark reveals a green centre.
• Damage is limited to the sunny or wind-facing side, while the inner growth looks denser and fresher.
• Deep inside the shrub, rich green needles or the first tiny new shoots are still visible.

Check individual branches carefully: use your fingernail or a sharp knife to lightly score the bark. If the tissue beneath is pale green and moist, that shoot is still alive. It should only be treated as dead when it is brown and dry inside.

The biggest March mistake: cutting back too early and too hard

Many gardeners panic in March: brown means dead, so it has to go. That response can deprive rosemary of the energy it needs to produce new growth.

Rosemary bushes often produce fresh growth from wood that looks dead in spring.

For this reason, inspect the plant at the start of the month but avoid major shaping or hard pruning. Wait until the worst frosts have passed and clearly visible green tips begin to emerge. Only then can you see which branches are genuinely dead.

How to care for brown rosemary in March

Steps that will help your plant now

• Water lightly: Water sparingly on frost-free days, especially container-grown plants. The rootball must not become completely dry.
• Provide wind protection: Cold easterly winds dry out the needles even further. Horticultural fleece or a sheltered spot against a house wall can make a major difference.
• Insulate the pot: Stand containers on wooden battens and wrap them with coir mats, hessian sacks or polystyrene boards.
• Do not feed: Avoid fertiliser until April. The plant needs time to recover and stabilise first.
• Loosen the surface carefully: In free-draining beds, gently loosen the top layer of soil around the plant without disturbing its roots.

What to avoid in late winter

• Do not prune hard while frost is still likely.
• Do not allow permanent wetness or leave pots standing in saucers full of water.
• Do not move rosemary into a warm, dark indoor room – it requires light and cool conditions.
• Do not repot during winter, as this places extra stress on the roots.

Essentially, the aim is to give the plant calm and stability rather than creating more stress through well-meant intervention.

Which rosemary varieties cope best with cold weather

Alongside location and care, the variety has a major influence on how brown your rosemary becomes in March. Here is an overview:

Rosemary type	Frost tolerance	Notes
Classic culinary rosemary (Rosmarinus officinalis)	Low to medium	Tolerates only brief periods down to around –8 °C and needs a dry, sheltered position.
‘Arp’	High	Considered one of the hardiest varieties and particularly suitable for beds in colder areas.
‘Blue Winter’	Medium to good	Considerably more resilient than standard forms, but sensitive to waterlogging.
Creeping rosemary (Rosmarinus prostratus)	Low	Best for milder locations or as a container plant with frost protection; visually very attractive.
‘Veitshöchheimer Rosmarin’	Good	Proven for Central European conditions, provided the soil is well drained.

Gardeners in exposed or colder areas will generally do much better with hardy varieties such as ‘Arp’ or ‘Veitshöchheimer Rosmarin’. In sheltered courtyards or on south-facing balconies, classic culinary rosemary can also perform reliably – as long as the pot is not sitting in water.

The right time to prune rosemary

Only cut rosemary back once winter has genuinely retreated. Two signs are crucial:

• No severe frosts are forecast.
• Fresh green growth is clearly visible at the shoot tips.

You can then use the secateurs with care:

• Cut only into green wood, rather than cutting back into completely old, thick wood.
• Remove dead branches that are brown inside entirely.
• Shape the shrub lightly instead of cutting it back brutally.

A gentle shaping prune after new growth appears produces compact, vigorous plants – and plenty of aromatic sprigs for the kitchen.

Location, soil and protection: helping rosemary survive many winters

To prevent rosemary from turning completely brown in the first place, it is worth getting the basics right. An ideal position acts like insurance for the years ahead.

The ideal garden position

• Sunny but sheltered from wind: A warm house wall or courtyard offers good protection from easterly winds.
• Free-draining soil: Mix in sand, grit or fine gravel so rainwater drains away quickly.
• Plant slightly raised: A small mound or stone wall helps prevent water from sitting around the roots.

Special rules for rosemary in pots

• Use only pots with a large drainage hole, ideally with broken terracotta pieces for drainage.
• Improve the growing medium with sand or expanded clay; do not use ordinary multipurpose compost alone.
• Move the container close to a house wall in winter and insulate the pot.
• Keep it slightly too dry rather than too wet, especially during prolonged rain or thaws.

Adding a layer of brushwood or fir branches around the root area in late autumn will also take some of the harshness out of winter.

Risks, warning signs and when starting again makes sense

Occasionally, damage is so extensive that rescue is no longer worthwhile. If most shoots are brown inside, the bark is shrivelled and there is no fresh green growth anywhere, replacing it with a young plant may be sensible – ideally with a hardier variety from the outset.

Before making a final decision, allow for one last test of patience: many shrubs do not reshoot from the lower areas until April or even early May. The plant is very likely dead only if no new growth appears over several weeks.

Once you understand that rosemary in March often merely looks “weather-beaten”, it is easier to stay calm. With the right location, restrained winter care and carefully timed pruning, most brown bushes can be restored remarkably well into dense, fragrant herb shrubs – rather than being thrown onto the compost too soon.