Growing Rosemary in Scotland: The Complete Guide

Salvia rosmarinus

Rosemary is hardy through much of the UK and established plants survive down to about -8°C; what kills it is cold, wet soil around the roots, and the single most important thing you can do for it is dig grit into the planting hole.

It's a low-maintenance evergreen shrub that gives you aromatic leaves for cooking every month of the year, pale blue flowers in spring that attract bumblebees, and a scent that releases every time you brush past it. Once established against a warm wall in soil that drains freely, a rosemary bush will stand for years.

Why rosemary needs drainage in Scotland

Rosemary is a drought-tolerant plant from the Mediterranean: it evolved to survive dry summers, not wet winters, and a wet Scottish winter is the opposite of what it is adapted to. A south-facing wall reflects heat and keeps the ground drier on top of whatever grit you've worked in, while the same plant in heavy clay that stays saturated through winter will rot at the roots and die before spring.

Cold-Hardy Herb Border Design → works through how to tier rosemary and other Mediterranean herbs by hardiness in a permanent border.

Varieties

An upright form gives you the most leaves for cooking; a prostrate form works well in containers and over walls. Miss Jessopp's Upright and Foxtail both carry the RHS Award of Garden Merit, a UK-wide award, not a Scottish one.

Also worth considering

Best Rosemary Varieties for Scotland → compares all named rosemary varieties head-to-head, with the practical detail that doesn't fit in a summary card.

Site and planting

Rosemary needs full sun and well-drained soil, and will tolerate poor dry soil. Choose the sunniest, most sheltered spot you have. A south-facing wall is ideal. The reflected heat keeps the soil drier and the plant healthier.

Plant in spring, once the soil is starting to warm up. Dig a hole wider than the rootballThe mass of roots and the soil or compost clinging to them, as it comes out of a pot or out of the ground when a plant is lifted. Full definition →. Mix a generous handful of horticultural grit into the bottom of the hole and into the backfillThe soil (sometimes improved with grit or compost) used to fill the gap around a plant's roots after it's placed in its planting hole. Full definition → soil. Compost and manure aren't needed. Rosemary wants light, free-drainingSoil that lets water pass through quickly rather than pooling, so roots aren't sitting in wet ground after rain. Full definition → soil, not rich damp soil.

Space plants 45cm apart if planting a hedge. Water in well after planting and then leave it. Rosemary does not need regular watering once established.

For containers, use a pot at least 30cm wide and deep with plenty of drainage holes. Fill with peat-freeCompost made without peat, which is harvested from a slow-forming, carbon-storing wetland habitat that peat extraction damages. Full definition → soil-based compost mixed with up to 25% horticultural grit by volume. Raise the pot onMoving a plant into a larger pot as its roots fill the current one, giving it more room and fresh compost before it becomes pot-bound. Full definition → feet over winter so water can drain freely, and move it to a sheltered spot in wet weather, such as near a building in a rain shadow. A pot gives you control over drainage, which is the variable that matters most in a wet winter.

Care through the season

Once established, rosemary needs almost no care. Do not water it except during prolonged drought. Plants in the ground don't need feeding; a pot plant that has stood in the same compost for over a year benefits from a sprinkling of general-purpose granular feed in late spring or early summer. In a very cold spell, cover ground plants with fleeceA lightweight, breathable fabric laid or draped over plants to trap a little warmth and keep off frost, wind and some flying pests. Full definition →, hessian or an old bedsheet.

Pruning: trim lightly after flowering in late spring or early summer. Cut just the spent flower stems and any straggly shoots. Avoid cutting into old brown wood: rosemary doesn't usually recover from heavy pruning. Regular light trimming keeps the bush dense and productive, and old, straggly plants are best replaced.

Harvesting: pick sprigs as you need them, all year round. The soft new growth in late spring and summer has the best flavour, but rosemary leaves are usable through winter. Cut whole sprigs rather than stripping individual leaves. The plant responds to regular harvesting by producing more new growth.

Propagation: take softwood cuttings from new growth in late spring or summer, or semi-ripe cuttings in summer; low stems can also be layeredPropagating a new plant by pinning a low, flexible stem into the soil while still attached to the parent, so it roots before being cut free. Full definition → in spring or autumn. Cut a 10 to 15cm piece from a non-flowering shoot. Strip the lower leaves, dip in rooting hormone if you have it, and insert into a pot of gritty compost. Keep in a sheltered spot. Take a cutting of your existing plant every few years so you have a replacement growing before the old bush reaches the end of its life.

Common problems

• Root rot from cold wet soil is the main cause of rosemary death in wet climates. Leaves turn brown. Improve drainage or move to a drier spot. If the whole plant is affected, it is probably too far gone.
• Rosemary beetle is a small metallic green-and-purple beetle that eats the leaves. Pick them off by hand and drop them into soapy water. Check the undersides of leaves for clusters of small grey larvae.
• LeggyDescribes a plant that's grown tall, thin and sparse rather than bushy, usually from too little light or not being pinched out. Full definition → bare stems mean the plant was not pruned regularly. Light annual trims keep it dense. Do not cut into old woodWhether a plant fruits on stems grown the previous year (young wood) or on older, established branches (old wood), which decides how it's pruned. Full definition →. Start a replacement plant from a cutting if the old one is too woody.

Common questions

Sources