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Open Source Apothecary At Home / The herbs
A memory herb with thin evidence, a genuinely excellent culinary herb, and a marginal plant in this climate. — Salvia rosmarinus
remedyRosemary (Salvia rosmarinus, long known as Rosmarinus officinalis) carries the most romantic reputation in the herb garden — remembrance — and the thinnest clinical evidence for it.
The memory claims do not hold up well. Rosemary aroma and extracts have been studied for memory and alertness, with small studies and inconsistent results. The effect sizes are small, the trials are few, and the popular claim considerably outruns them. This is a case where the folklore is charming and the evidence is not there.
What rosemary does have. It is a strong antioxidant in food, it is genuinely antimicrobial in the kitchen, and its culinary role — particularly with roast meat — is real and worth having. There is also some trial interest in rosemary for hair loss and for cognitive function in older adults, again with weak and mixed results.
It is the most marginal plant here. Rosemary, like lavender, is a Mediterranean shrub at the edge of its cold tolerance in zone 6a. It needs the best-drained, most sheltered spot on the property, or a large pot brought in for winter. Winter wet kills rosemary more often than winter cold does, which is the detail that decides success or failure.
The honest framing. Grow rosemary because it is wonderful in food and because it is a pleasure to have. Do not grow it expecting a memory cure.
Inhaling lavender and rosemary has been observed to improve cognitive function and sleep quality and reduce anxiety levels.PubMed 39047346 ↗
Although increasing Cd concentration decreased plant growth and nutrient uptake, mycorrhizal fungi was able to alleviate the stress by significantly increasing plant growth, nutrient uptake and phytoremediation potential.PubMed 36098857 ↗
Rosemary aroma decreased sleepiness and increased alertness in shift-working nurses.PubMed 33550193 ↗
Rosemary as a traditional herb could be used to boost prospective and retrospective memory, reduce anxiety and depression, and improve sleep quality in university students.PubMed 29389474 ↗
Taken together the data suggest potential beneficial properties of acute consumption of rosemary water.PubMed 30318972 ↗
| | | |---|---| | Life | Perennial evergreen shrub (tender here) | | Propagation | Cuttings — reliable and true to type. Seed is slow and variable. | | Light | Full sun | | Soil | Sharply drained, gritty, lean. Wet roots are fatal. | | Spacing | 60-90 cm; it can reach 1.5 m in a good year | | Hardiness | Marginal in zone 6a — shelter it or pot it | | Harvest | Sprigs year-round once established | | Winter | Wet cold kills it, not dry cold. Improve drainage and shelter before worrying about frost. |
Take softwood cuttings in early summer from a plant you like; they root in a few weeks and give you replacements when the parent succumbs to a bad winter. A south-facing wall, gravel mulch and a raised bed is the winning combination.
Culinary — the best reason to grow it, and the safest way to use it.
Tea — 1 teaspoon dried leaf per cup; strongly flavoured and somewhat resinous.
Infused oil — rosemary in oil for external use; traditional for scalp and muscle massage.
Tincture — the traditional preparation for the memory use, on thin evidence.
In food as an antioxidant — rosemary extract is genuinely used commercially to slow oxidation in oils and meat.