By Alastair Culham

Rosemary makes a tasty addition to many savoury dishes. My favourite is a rub of salt and crushed fresh rosemary leaves put on potatoes before roasting but it’s also lovely with lamb and even with citrus based desserts. Rosemary was probably introduced to the U.K. in Roman times and it is reported in Banckes’s herbal (1525) as a plant with a remarkable range of reported uses: “take the flowres and make powder therof and bynde it to the ryght arme in a lynen clothe, and it shall make the lyght and mery… Also take the flowres and put them in a chest amonge youre clothes or amonge bokes and moughtes shall not hurte them…. Also boyle the leves in whyte wyne and wasshe thy face therwith…thou shall have a fayre face. Also put the leves under thy beddes heed, and thou shalbe delyvered of all evyll dremes…. Also take the leves and put them into a vessel of wyne…yf thou sell that wyne, thou shall have good lucke and spede in the sale…. Also make the a box of the wood and smell to it and it shall preserne [preserve] thy youthe. Also put therof in thy doores or in thy howse and thou shalbe without daunger of Adders and other venymous serpentes. Also make the a barell therof and drynke thou of the drynke that standeth therin and thou nedes to fere no poyson that shall hurte ye, and yf thou set it in thy garden kepe it honestly for it is moche profytable….“

Outside of the U.K. the mystery of the plant increases and it is associated with Aphrodite, who in some versions of the myth arose from the sea clothed in rosemary.  The scientific and common names are derived from two Latin words: Ros, meaning dew, and marinus, meaning sea, and may be indicative of the common distribution of this plant near the sea.  Rosemary often has low growing (prostrate) forms on sea cliffs and many of these have given rise to cultivars selected for this low spreading growth although these genotypes are usually less frost tolerant than inland genotypes.  Prostrate rosemary forms also occur on mountains where similar exposure to strong winds favours low growing forms but these also have great cold hardiness.  If you are selecting a low growing rosemary cultivar it is therefore worth asking how hardy it will be.

Rosemary is also associated with aiding memory, both in ancient history and based on recent studies of it’s biochemistry.  It is used in wedding wreaths in Greece to represent memory of the wedding vows. It is also used at funerals in various places to indicate remembrance of the dead.

It was reputed to grow only in gardens of righteous people, and acted as a protection from evil spirits.  A further saying “Where Rosemary flourishes, the Woman rules” is widely reported as coming from France or traditional English but I have yet to trace the origin of this.

Biology of Rosemary

This perennial shrub from the Mediterranean basin with narrow green leaves and bright flowers and is both widespread and quite variable in flower colour and growth form.  The main species is Rosmarinus officinalis, this accounts for most of the distribution of the whole genus, however there are two (or possibly three) other species: R. tomentosus, R. eriocalyx and possibly R. palaui (this is usually treated as a prostrate variety of R. officinalis).  Having said that, evidence based on DNA based phylogenetic trees support strongly the inclusion of all of Rosmarinus in the much larger and more widespread genus Salvia. R. officinalis forms part of the dwarf scrub vegetation called ‘matorral’ that occurs as part of a fire controlled ecosystem in drier parts of the mediterranean.  A detailed study of genetic variation of the species suggests it has spread from the Iberian peninsula along both the northern and southern coasts of the Mediterranean sea reaching to Turkey but not as far as Israel.

Various growth forms of R. officinalis have been selected as named cultivars, almost exclusively for their differing flower colours or habits, for instance, ‘Miss Jessup’s Upright’ is a selection particularly suited for hedging.  What I find remarkable is that little selection has been done for culinary uses and rosemary is treated as just one standard species. Work by one of my PhD students, Anas Tawfeeq, studied the influence of genotype and cultivation techniques on the essential oil composition of rosemary and showed that the dominant influence on oil composition is the genotype, suggesting that work on selection of optimal types for cooking and for perfumery should be the focus of future research.

β-pinene

Verbenone

α-phellandrene

Alpha thujene

α-bisabolol

This blog has only scratched the surface of the uses and myths around rosemary.  However, if nothing else, I would suggest you put a rosemary plant in your garden so that you can enjoy the beautiful flowers and rub the leaves to pick up the relaxing smell.  It was a favourite of Gertrude Jekyll – and that should be recommendation enough!

Downderry Nursery, Kent are holders of the National Collection of Rosemary  (as well as  Lavender)  stock a range of rosemary cultivars for sale at their beautiful walled display garden and via the internet.

Photographed today, a semi-prostrate rosemary as a roadside planting.

Roadside rosemary in flower today (23 December 2017)

References

Isabel Mateu-Andrés, Antoni Aguilella, Fernando Boisset, Rafael Currás, Miguel Guara, Emilio Laguna, Antoni Marzo, Mª Felisa Puche, Joan Pedrola; Geographical patterns of genetic variation in rosemary (Rosmarinus officinalis) in the Mediterranean basin, Botanical Journal of the Linnean Society, 171, 2013, 700–712, https://doi.org/10.1111/boj.12017

Drew, Bryan T., González-Gallegos, Jesús Guadalupe, Xiang, Chun-Lei; Kriebel, Ricardo; Drummond, Chloe P., Walker, Jay B., Sytsma, Kenneth J., 2017. Salvia united: The greatest good for the greatest number  Taxon, 66, 133-145 DOI: https://doi.org/10.12705/661.7

A Tawfeeq, A Culham, F Davis, M Reeves 2016. Does fertilizer type and method of application cause significant differences in essential oil yield and composition in rosemary (Rosmarinus officinalis L.)? Industrial Crops and Products 88, 17-22 https://doi.org/10.1016/j.indcrop.2016.03.026

A Tawfeeq, A Culham, F Davis, M Reeves, N Michael, 2016 The influence of genetic variation on essential oil composition in Rosmarinus officinalis L., the common rosemary. Planta medica 80 (S1), S1-S381