Thyme, oregano, sage and rosemary

Not outdoors, except on the mildest parts of the coast. Rosemary is hardy to zone 7 or 8 (the toughest cultivars, ‘Arp’ and ‘Madeline Hill’, to zone 6 with shelter), so in the rest of the country it is a pot plant: bring it to a cool, bright window two or three weeks before the first frost, water sparingly, and expect it to sulk until spring. Many gardeners simply buy a new plant each May and dry the old one in September.

Cut stems just before flowering, tie them in small loose bunches and hang them upside down inside paper bags with a few holes in a warm, dark, airy place for one to two weeks — or on screens, or in a dehydrator at 35–45 °C. They are dry when a leaf crumbles and a stem snaps. Strip the leaves, store them whole in sealed jars out of the light, and crumble them as you cook. They keep a year.

Any time for a sprig, but for drying cut them just before they flower, when the oils are strongest — June and again in late summer for thyme and oregano, two main cuts a season for sage. Mid-morning after the dew dries. Take no more than a third to half of the plant, go lightly on first-year plants, and make the last big cut by early to mid-September so the plant hardens before winter.

Yes: whole sprigs in a freezer bag, snipped off frozen as you need them, keep their flavour well, and sage leaves chopped into softened butter and frozen in a log are better than dried sage for roasts and stuffing. Freezing is the alternative, not the improvement — these are the herbs that genuinely dry well, so dry the bulk and freeze a bag for convenience.

Only in the fridge for up to four days, or in the freezer. Oil keeps air away from the herbs and garlic, which are low-acid, and that is the setting in which botulism bacteria grow without any smell or sign; dried herbs in oil are no safer than fresh. The shelf-stable versions in shops are acidified by a process you cannot copy at home. Herb vinegars are acid and keep safely on the shelf.

Drainage first: they die of wet roots far more often than of cold, so plant them in a raised or sloping bed with a gravel mulch rather than wet leaves. Stop hard cutting by mid-September. After the ground freezes, lay evergreen boughs or straw over oregano and thyme in zones 4–5 and lift it in April. Leave the browned tips on until new growth shows in spring, then cut back. Sage is short-lived; replace it every three to five years from cuttings.

Rub a leaf of each between their fingers and name the smell — pizza (oregano), stuffing (sage), roast potatoes (rosemary), and thyme, which smells like all of them — and all four are safe to taste straight from the plant. Children are good at the two jobs that matter: stripping dried leaves off stems into a bowl, and tying the bunches. Sage leaves are furry and a favourite to stroke; a bee on a thyme flower in June is the first bee most kids watch up close.