January is a quiet month in the garden; the long hot days between the first and second flush of roses discourage all but watering, deadheading, and seed collection. It's the month to drag a chair into a shady corner and read and think and dream, a time to plan what to plant when the cooler weather comes, and to enjoy the summer herbs.

The comfrey is just about to flower for the second time this season, pushing up a long stalk on which many flowers stand one above the other, long and hollow, and, as Culpeper says in his famous herbal, 'like the finger of a glove, of a pale whitish colour'. That the plant in my garden fits Culpeper's 1826 description, that I can open his book and hear what he has to say about comfrey all these years after he said it, is like some fantastic conjuring trick; the connection with another mind, regardless of time and place, is the magic that keeps writers writing and readers reading.

- Comfrey -

Culpeper's Complete Herbal and English Physician, with its constant references to 'fluxes of blood' and 'humours', to 'women's courses' which swing between 'the reds and the whites', offers insight into daily life in nineteenth-century Britain. It was a time when medicine was still entwined with the ancient art of astrology - according to Culpeper comfrey is governed by the planet Saturn, which brings it under the sign of Capricorn and gives it a cold, dry, earthy quality.

I too was born under the sign of Capricorn, and it tickles me to think that the comfrey plant and I have something in common. With its deep roots, comfrey brings up nutrients that have leached into the soil and makes them available to other plants when its leaves break down in winter. Is it fanciful to see this as a botanical equivalent of the writing process?

Whatever the astrological properties claimed by Culpeper for comfrey, its modest flowers are sweet, and its leaves when chewed heal mouth ulcers.

My great favourite, the clary sage, is beginning to set its seed. The tall mauve and pinkish flower spikes are drying, each tiny bell-shaped cup becoming papery until, when you squeeze them, the glossy brown seeds fly out. I love this plant for its unique scent. Run a hand up the flower spikes as you pass, and the perfume lingers on the skin for hours. It's used in France in the perfume industry, and many women have told me how their midwife dispensed the essential oil of clary to bring on labour. Clary sage also encourages sleep, so a stem of flowers in the pillowslip at night can help insomnia.

The best of the sleep promoting herbs is valerian. It's on my list of plants to sow when autumn comes. I'm also dreaming of those very dark, almost black, hollyhocks, a variety called “The Watchman”. In the meantime I'm reading Philosophy In The Garden by Damon Young, a book about writers, from Jane Austin to Socrates, and their relationships with gardens. If you can locate a copy, it's the perfect companion for these lazy, heat-soaked weeks of January.