The first three rosemary plants I bought all died in their first winter. Not because of frost, although that is what I assumed at the time, but because they had been sitting in waterlogged Oxfordshire clay since October and the roots had simply rotted. By the time spring came around they looked fine on top and entirely dead below. I bought another one, planted it the same way, and watched the same thing happen.
It took me three failed attempts and a chat with an old gardener at the local allotment before I worked out the truth. UK rosemary does not die from cold. It dies from wet feet. Once I understood that, my rosemary went from being the herb I kept replacing to one that has been with me for over fifteen years. This guide is how I have come to grow it in the UK, with all the bits the generic gardening websites tend to skip over.
Why Rosemary Dies in UK Gardens (and How to Stop It)
This is the single most important thing to understand. Rosemary is a Mediterranean plant from the dry rocky hills of southern Europe. It evolved in conditions where rain drains away quickly, the soil is poor and gritty, and the air is warm. Then we plant it in damp British soil, water it because we water everything, and wonder why it dies.
Rosemary in the UK does not generally die from cold. Most varieties, particularly the hardier ones like Miss Jessopp’s Upright and Tuscan Blue, are tough down to around -15°C, which is colder than anywhere in the UK gets in a normal winter. What kills them is sitting in cold wet soil all autumn and winter. The roots cannot breathe, fungal diseases set in, and the plant slowly rots from the bottom up.
The fix is drainage, drainage, and more drainage. If your soil is heavy clay like mine, this matters even more. How to tell if your garden soil is clay, loam or sand covers the simple checks, and if you do have clay, how to improve drainage in clay soil walks through the long-term work. For rosemary specifically, you need to either dramatically improve the soil at the planting spot or grow it in a pot where you control the drainage entirely.
The Best Rosemary Varieties for UK Gardens
Variety matters more with rosemary than with most herbs. The hardiness varies considerably between cultivars, and choosing the right one for your garden is the difference between a thriving plant and a dead one in February.
The hardy reliable ones
Miss Jessopp’s Upright. The most reliable variety for British gardens by some distance. Tall, vigorous, upright habit, blue flowers, good flavour. This is the one I grow and the one I would recommend to anyone in the UK. Tolerates winters down to about -15°C if the drainage is right. Available from RHS-recommended sources and most decent garden centres.
Tuscan Blue. Strongly flavoured, beautiful deep blue flowers, slightly less hardy than Miss Jessopp’s but still good for most of the UK. A favourite for cooking because the leaves are bigger and more aromatic.
Severn Sea. A semi-prostrate variety that arches and trails, good in pots or over walls. Reasonably hardy.
The pretty but tender ones
Prostrate or trailing rosemary (often sold as Rosmarinus officinalis ‘Prostratus’). Lovely for cascading over pot edges but considerably less hardy than upright varieties. Often dies in a normal UK winter. Beautiful but treat as a tender plant and overwinter under cover if you want to keep it.
If you are buying from a garden centre, look at the label. It should say “hardy” and ideally name the variety. If it just says “rosemary” without a cultivar name, ask. The unnamed plants are sometimes the prostrate type that will not survive a UK winter outdoors.
Growing Rosemary Outdoors in the UK
Rosemary thrives in the ground in most UK gardens as long as the conditions are right. Get the drainage and position sorted at planting time and you have got a plant that can live for 15 to 20 years with very little attention.
Position and sun
Full sun, all day if possible. Rosemary is a sun-worshipper and the more sun you give it the better it crops and the hardier it becomes through winter. A south or west-facing spot is ideal. Sheltered from cold winds is a bonus, particularly in the north of the UK, but the priority is sun first, shelter second.
Against a south-facing wall is genuinely the best position you can give it in a UK garden. The wall absorbs and radiates heat, the rain sheets off rather than pooling around the roots, and the plant gets the warmest microclimate available.
Soil and drainage
Free-draining and on the poor side. This is the opposite of what most UK gardeners assume. Rosemary actually grows better in poor stony soil than in rich loamy compost. Heavy clay, water-retentive soil, or anywhere that puddles after rain will kill it eventually.
If you have clay, prepare the planting spot by digging out a wider and deeper hole than you would normally, mixing the soil that comes out with roughly half its volume in horticultural grit, and refilling. Plant the rosemary slightly higher than the surrounding soil so water drains away from the crown rather than sitting around it. A mulch of gravel or grit at the base, not bark or compost, finishes the job. The whole approach is to create a Mediterranean island in the middle of your British garden bed.
How to improve garden soil in the UK covers the broader principles and best vegetables to grow in clay soil covers what does work in heavy ground (rosemary is generally not on that list).
Watering established plants
Almost nothing once they are established. A mature rosemary plant in the ground in the UK gets enough water from rainfall for the whole year. The only times I water mine are during proper drought spells in July or August, and even then sparingly. Overwatering kills rosemary faster than anything else. If in doubt, do not water it. How often to water plants in the UK covers the principle that rosemary takes to an extreme.
Growing Rosemary in Pots
For most UK gardens, especially those with heavy soil or shaded patches, a pot is genuinely the easier option. You control the drainage entirely, you can move the plant to the sunniest spot you have, and you can bring it under cover in extreme weather if needed.
Pot size
Big. Rosemary develops a serious root system and a small pot will check it within a year. Start with a 35cm pot minimum and expect to pot on into something bigger after two or three seasons. A mature rosemary in the right pot can reach 1 metre tall and almost as wide.
Terracotta is genuinely better than plastic for rosemary because the porous material lets the compost breathe and dry out between waterings. The slight inconvenience of more frequent watering in summer is more than offset by the drainage advantage in winter. Growing vegetables in pots in the UK covers the wider container principles, and best vegetables to grow in pots covers what else works in containers.
Compost mix
Do not use straight multipurpose compost. Mix it 50/50 with horticultural grit, or two thirds peat-free multipurpose to one third coarse grit. The mix should drain almost instantly when you water it. If water pools on the surface for more than a few seconds, you have not added enough grit. Peat-free compost in the UK covers the modern compost options and best compost for vegetables covers which brands work properly.
Watering pot rosemary
Less than you think, even in summer. Let the top 5cm of compost dry out completely between waterings. In winter, water only if there has been a proper dry spell with no rain for two weeks or more. The combination of small reservoir of compost plus winter rainfall is enough for nearly the whole year.
Getting Rosemary Through Winter
This is where most UK rosemary plants are lost, so it gets its own section. The good news is that protecting rosemary through winter is not about wrapping it up against the cold. It is about keeping the roots from drowning.
For ground-grown rosemary
If you have prepared the planting site properly with grit and elevation, there is genuinely nothing else to do. The plant survives the winter on its own. The grit mulch at the base helps prevent waterlogging at the crown. The free-draining soil mix means the roots stay relatively dry even in wet weather. No fleece, no horticultural wool, no protection needed.
The only time I would consider winter protection for an established rosemary in the ground is in an exceptional cold snap (think -10°C or below for several days), and even then I would only protect young plants under three years old. Mature plants are remarkably tough. Frost damage on plants in the UK covers the wider winter picture for less hardy plants.
For pot-grown rosemary
A few practical steps make a real difference. Move pots up against a wall or fence in November to give them some shelter. Stand the pot on pot feet or bricks rather than directly on the patio so water drains away properly. If your patio is in shade or holds water, move the pot somewhere drier and slightly more sheltered for the worst months. The pot itself rarely needs wrapping. It is the standing water issue you are solving, not the cold.
One thing I have learned the hard way: never let a pot of rosemary sit in a saucer of water at any time of year, but especially in winter. The saucer becomes a death trap. Tip them out every time it rains heavily.
Growing Rosemary from Seed
The honest answer is do not bother. Rosemary from seed is slow, unreliable, and barely worth the effort.
The germination rate is poor (often 30% to 50%), germination is slow (6 to 8 weeks is normal), and the resulting plants take two to three years to reach a usable size. A small starter plant from a garden centre at £5 to £8 gives you something you can harvest from immediately. A rosemary cutting taken from an existing plant (yours or a friend’s) roots within a few weeks and gives you a proper plant within a year. Both options are dramatically better than seed.
If you genuinely want to grow rosemary from seed, sow shallowly in spring into a tray of seed compost on a warm windowsill, expect 6 to 8 weeks for germination, and be patient. How to grow vegetables from seed in the UK covers the wider technique. But know that you could be eating fresh rosemary from a £5 starter plant before your seedlings are even potted on.
Taking Rosemary Cuttings (Free Plants for Life)
Here is the genuinely useful skill. Rosemary cuttings are dead easy and give you new plants for free. Once you have one healthy rosemary plant, you never need to buy another. I have given dozens of rosemary plants away over the years, all from cuttings off my original Miss Jessopp’s.
- Take semi-ripe cuttings in summer (July or August is ideal). Choose this year’s growth that has started to firm up but is not yet woody.
- Cut 10 to 15cm lengths just below a leaf node.
- Strip the bottom two thirds of leaves off, leaving 4 to 6 leaves at the top.
- Push the cutting into a small pot of free-draining gritty compost (the same 50/50 compost-and-grit mix as for adult plants).
- Water once, then keep on a bright windowsill or in a cold frame. Do not water again unless the compost is bone dry.
- Cuttings should root within 4 to 8 weeks. Resist the urge to check by pulling them out.
- Pot on into individual 15cm pots once you see new growth appearing at the top.
One good plant can give you 10 to 20 viable cuttings every summer. After two years you have a hedge if you want one.
How to Grow a Rosemary Hedge
A rosemary hedge is an under-appreciated UK garden feature. It is evergreen, sweetly scented, attractive to bees, drought-tolerant, and looks distinctly Mediterranean against a British backdrop. The flowers from May to July are stunning. And once it is established, the only maintenance is an annual trim in spring.
For a hedge, choose Miss Jessopp’s Upright. The tall vertical habit is what you want, and the hardiness means the hedge will not have gaps from winter losses. Plant young plants 40 to 50cm apart in a free-draining trench that has been prepped with plenty of horticultural grit. Water them in well at planting, then leave them alone. By year three you have a continuous hedge 80cm to 1.2m tall.
Trim once a year in early spring, just before new growth starts. Never cut back into old bare wood, rosemary does not always regenerate from old wood and you can lose a plant by being too aggressive. Light shaping each year keeps it dense and productive.
Harvesting and Using Rosemary
One of rosemary’s best features is that you can harvest from it all year round in most of the UK. The leaves are evergreen and the flavour is just as strong in February as in August, sometimes stronger because the slow winter growth concentrates the oils.
Cut sprigs as needed using kitchen scissors or secateurs. Always cut from the soft new growth at the tips, not back into old woody stems. A good plant can spare 10 to 15 sprigs a week without noticing. Strip the leaves off the stems for cooking, or use whole sprigs to flavour roasts and stocks.
Rosemary dries beautifully, unlike basil or coriander. Hang small bunches in a dry airy place for two weeks, then strip the leaves into a sealed jar. Dried rosemary keeps its flavour for 12 months or more, far longer than most herbs.
Common Rosemary Problems
- Plant slowly dies from the bottom up. Root rot from waterlogged soil. The classic UK rosemary killer. Improve drainage drastically or switch to a pot with a gritty mix.
- Leaves turning brown and dropping in winter. Almost always waterlogging at the roots, sometimes combined with cold wet wind. Improve drainage and shelter the plant.
- Sparse leggy growth. Usually too much shade. Move to a sunnier spot or accept reduced cropping.
- Yellowing leaves on a healthy plant. Sometimes nutrient deficiency in old compost (in pots). A light liquid feed in spring usually sorts it. Avoid heavy feeding, which softens the growth and reduces flavour.
- Rosemary beetle. A relatively new pest in the UK, distinctive metallic green and purple striped beetles on the leaves. Pick them off by hand. The RHS rosemary beetle page covers identification and control in detail.
- Mildew on leaves. Usually too damp and too crowded. Improve airflow by thinning out congested branches in spring.
When to Plant Rosemary in the UK
The best time to plant rosemary outdoors in the UK is spring, from April through to early June, once the soil has warmed and the worst frosts are past. Spring planting gives the roots an entire growing season to establish before facing the wet winter that kills most newly-planted rosemary.
Autumn planting (September or October) is technically possible but I have lost more rosemary plants to autumn-planting failures than to anything else. The roots simply do not establish enough before winter wet sets in, and the plant rots over its first cold months. Stick to spring if you possibly can.
For a pot-grown plant, the timing is more flexible. You can plant into a fresh pot any time from March to September. Avoid the dead of winter purely because the plant is dormant and does not need disturbing.
Common Questions About Growing Rosemary
Why does my rosemary keep dying in winter?
The most common cause is waterlogged soil, not cold. Rosemary is hardy down to around -15°C but cannot tolerate wet roots through winter. Improve drainage by planting in gritty soil, raising the plant slightly above ground level, and using a gravel mulch instead of bark or compost. For pots, switch to a 50/50 compost-and-grit mix.
What is the best rosemary variety for the UK?
Miss Jessopp’s Upright is the most reliable rosemary variety for British gardens. It has an upright habit, tolerates winters well, has good flavour, and is widely available. Tuscan Blue is another strong choice for cooking. Avoid prostrate or trailing rosemary varieties unless you plan to overwinter them under cover, as they are considerably less hardy.
Can you grow rosemary in pots in the UK?
Yes, and it is often easier than growing in the ground, especially on heavy clay soil. Use a 35cm pot or larger with a 50/50 mix of peat-free compost and horticultural grit. Place in full sun. Water sparingly and never let the pot sit in a saucer of water. In winter, move pots against a wall and raise them on pot feet for better drainage.
How often should I water rosemary?
Almost never, once established. Ground-grown rosemary gets enough water from rainfall for the whole year in most UK gardens, except during proper drought. Potted rosemary needs watering occasionally in summer when the top 5cm of compost is dry, and rarely in winter. Overwatering kills rosemary faster than anything else.
When should I plant rosemary in the UK?
Spring is best, from April through to early June. This gives the roots an entire growing season to establish before facing winter wet. Autumn planting often fails because plants do not establish before cold wet conditions set in. For pot-grown plants, any time from March to September works.
Should I grow rosemary from seed or buy a plant?
Buy a plant or take a cutting. Rosemary from seed is slow (6 to 8 weeks to germinate), unreliable (30 to 50% germination), and takes 2 to 3 years to reach usable size. A £5 starter plant gives instant results, and one healthy plant produces free cuttings every summer to make as many new plants as you want.
How do I take rosemary cuttings?
Take semi-ripe cuttings in July or August from this year’s firming growth. Cut 10 to 15cm lengths just below a leaf node, strip the lower two thirds of leaves, push into gritty compost, water once, then keep on a bright windowsill. Cuttings root in 4 to 8 weeks. One mature plant gives 10 to 20 viable cuttings every summer.
A Sensible Place to Start
If you have never grown rosemary, here is the plan. Buy one Miss Jessopp’s Upright plant at any garden centre in spring for £5 to £8. Pot it into a 35cm terracotta pot of 50/50 peat-free compost and horticultural grit. Stand the pot in the sunniest spot you have, ideally against a south-facing wall. Water it once now, then leave it alone unless we get a proper drought. Move the pot up against the wall in November and stand it on pot feet for the winter.
That one plant will give you rosemary for 15 years if you treat it right. In year two, take a few cuttings in summer and you have a second plant for free. In year three, you can plant one in the garden in a properly drained spot and watch it grow into a real Mediterranean feature.
To build a wider herb collection, how to grow herbs in the UK covers the full picture, and the cluster guides for parsley, mint, chives, and basil walk through the other kitchen essentials. Gardening for beginners in the UK covers the wider first-year approach if you are just starting out.