Rosemary, sage, thyme and oregano are Mediterranean plants that want full sun and sharp, well-drained soil and tolerate drought once established. They are intolerant of wet, heavy or poorly drained soil and are easily over-watered, which invites root and stem rot. They also do better in lean soil than rich - over-feeding grows lush, low-flavour foliage and encourages disease - so water sparingly and keep feeding light.
Promising · suboptimal if ignored → advise
How it works
These species are adapted to dry-climate Mediterranean conditions - gritty, fast-draining soils and low summer water. In wet or heavy, poorly drained soil the root zone stays waterlogged, starving the roots of oxygen and rotting them; excess water and rich fertility compound the rot risk and, in these aromatic herbs, thin the essential oils that carry the flavour.
What to do about it
Site in full sun with excellent drainage: plant in well-drained ground, a raised or gritty bed, or open up heavy clay with coarse material before planting. Let the soil dry between waterings and water sparingly once the plant is established, and keep the soil lean rather than feeding it heavily.
How much it matters: No figure is stated or invented. Wet feet drive root and stem rot and decline; sharp drainage, restraint on water, and lean soil let the plant thrive. Because siting, watering and feeding are all the gardener's to control, the rule advises rather than warns.
The evidence
Evidence: confirmed against 3 sources in the research-based literature.
the 3 sources
Clemson HGIC, 'Herbs', hgic.clemson.edu/factsheet/herbs (read 2026-08-22): 'Many common herbs are from the Mediterranean region. They grow well in full sun, well-drained soil, and dry summers'; rosemary - 'All grow best in dry, sunny areas in well-drained soil'; sage - 'The plants require excellent drainage and dry soil in full sun'; thyme - 'Plant thyme in full sun in very well drained soil that stays dry'; oregano - 'Plant oregano in full sun and well-drained soil'; 'Most herbs do not need a highly fertile soil. Very fertile soils tend to produce lush leaves that lack flavor.'
Univ. of Maryland Extension, 'Care of Herbs and Starting Herbs from Seed', extension.umd.edu/resource/care-herbs-and-starting-herbs-seed (read 2026-08-22): 'Drainage is probably the most important single factor in successful herb growing'; 'Herbs will not grow in wet soils'; 'The "Mediterranean" herbs, such as basil, thyme, rosemary, oregano, and lavender, grow best on sunny, dry sites in light (sandy) soil'; 'Over-fertilizing herb plants can lower the plant's essential oil content and encourage root and stem rot diseases.'
NC State Extension Gardener Plant Toolbox, 'Salvia officinalis', plants.ces.ncsu.edu/plants/salvia-officinalis (read 2026-08-22): 'Common sage prefers full sun and well-drained, medium to dry soils that mimic those of its Mediterranean homeland'; 'It is intolerant of wet or poorly drained soils'; 'It will tolerate drought and poor soils.'
Where this rule stops
A STANDING CULTURAL ADVISORY (trigger.kind always), gated by applies_to to the four Mediterranean culinary herbs the sources name - rosemary, sage, thyme, oregano. It surfaces on those species pages and can be cited by the herb guides; it gates nothing and docks no score - the app cannot see a bed's drainage or how it was watered. Moisture-loving herbs (lemon balm, mint, basil at higher water, parsley, cilantro) are deliberately NOT in this group and are left off until sourced on their own terms.
Plants this fires on
Change history
Every change to this rule is one commit. This is what the project's version history records — the date and the reason — not a summary of it.
- Mediterranean woody herbs need sharp drainage; wet feet rot them
Cite this page
Milpa Gardens. "Rosemary, sage, thyme and oregano are Mediterranean plants that want full sun and sharp, well-drained soil and tolerate drought once established. They are intolerant of wet, heavy or poorly drained soil and are easily over-watered, which invites root and stem rot. They also do better in lean soil than rich - over-feeding grows lush, low-flavour foliage and encourages disease - so water sparingly and keep feeding light." Evidence grade: Promising. https://milpa.garden/rules/rosemary-sage-thyme-oregano-mediterranean-plants-that/
A garden-planning corpus: every claim states its evidence grade and links its sources on the page. Cite it with the grade, and add the date you read it.