And the other free sources: windowsills, friends, and the sad shelf
Supermarket basil and mint will root in a glass of water within a fortnight and can be potted up for a bright kitchen windowsill. Rosemary and thyme take from short semi-ripe sprigs pushed into gritty compost. A plant swap with two neighbours and a box of cuttings costs nothing and gets you varieties no shop stocks.
Garden centres also clear tired-looking perennials at this time of year. A plant with scruffy foliage and a healthy root system is a bargain, because the top growth is about to disappear anyway; just check that the roots are firm and pale rather than brown and mushy, and get it in the ground quickly.
Is it too late in the year to divide perennials?
For most hardy herbaceous perennials, autumn division is fine as long as the soil is still workable — not frozen, not waterlogged — because the roots keep growing quietly underground long after the top has given up. The exceptions are grasses and anything slightly tender or grey-leaved, like lavender and salvias, which sulk if disturbed in the cold and are better left until spring.
What can I propagate indoors on a windowsill right now?
Soft herbs are the obvious win: mint, basil and lemon balm root in water, while rosemary and sage prefer damp gritty compost and a clear bag over the pot. Many houseplants also oblige at this time of year — pothos, tradescantia, spider plant offsets and leaf cuttings of begonia and sansevieria — so a cold weekend indoors can still end with six new plants on the sill.
