Gardening: cuttings

Jean Hill, of Chittlehampton in north Devon, is worried about her panther lilies. "I sowed seeds of Lilium pardalinum in October 1986 in a 5-in pot and they grew well," she writes. "I left them in situ until 1990 when I planted them out, undisturbed, into our very fertile, acid Devon soil.

"In 1992 and 1993 they bloomed very well but, unsurprisingly, they were overcrowded, so in October I divided them. The bulbs were very big and I gave some to two friends and planted three groups of them in my own garden. We all three, living several miles apart, have had this same result.

"In 1994, they showed shoots, but only 2in high. Every year since they have showed shoots, this year reaching 6in, but nowhere near flowering size. I recently dug up one of my groups of bulbs, just as the foliage was changing colour. They were very healthy little bulbs and roots.

"My friends have one group in light woodland, the other in the vegetable garden. We are all very patient gardeners, but are now beginning to lose patience. Why have the bulbs stopped flowering?"

Lilium pardalinum, the panther lily, is a showy and generally easy American species that in the wild grows up to at least 5ft. The flowers curve back on themselves and are richly red and gold, with dark spots round the centre. Left to itself the plant makes a matted mass of rhizomatous roots, with little clusters of bulb-like scales providing the growing-points for the flowering stems. The mat is important, as it provides the reservoir of food and drink for the flowering stems above.

Since Mrs Hill and all her friends have suffered the same problem, I would guess that the disturbance caused by dividing the original clump is probably the cause of the lilies taking a step backwards. Perhaps too much of the rooty mat was lost in the division, so that the lilies need to build themselves up underground again before they have the strength to flower.

Our recent dry summers may be a problem, too. What Lilium pardalinum likes best is a soil that is well drained, but moist too, with plenty of leaf mould and humus to keep the root-run cool. It doesn't like wind and it doesn't like deep shade. The acid soil that Mrs Hill talks of should suit the plant well, provided it does not dry out. The bulbs are happiest with at least 5in of soil on top of them.

But at least they seem to be trying to recover lost ground. The growing shoots are getting bigger each year, rather than disappearing altogether. When they have built themselves up to their former strength I am sure they will come into bloom again. Meanwhile, Mrs Hill needs to keep them well watered.

The winter lecture series arranged by the University of Oxford's botanic garden starts this Thursday, when the garden designer Noel Kingsbury talks about the "new wave" of perennial planting (mass planting, German fashion, for anyone still riding the old wave). In this series, lecturers have been invited to explore "Passions and Prejudices". There will be plenty of both on 29 January, when Robin Lane Fox explains the way to "Better Gardening". Lectures start at 8pm in the Garden Quadrangle Auditorium, St John's College, Oxford. Tickets, pounds 6 a lecture, from Louis Allen, at the Botanic Garden, Rose Lane, Oxford OX1 4AX (01865 276920).

Anna Pavord