Taking autumn cuttings that actually root
Semi-ripe cuttings taken in early autumn are the most forgiving. Pick a shoot from this year that is firm at the base but still flexible at the tip, cut just below a leaf node and strip the lower leaves.
What made the difference
Gritty compost, a clear bag over the pot, and leaving them alone. Checking every day did more harm than any frost. Lavender and rosemary rooted within five weeks; the salvias took longer.
Next year I want to try hardwood cuttings of the currants in November and simply stick them in a trench by the fence.