Kim Wilde answers your gardening questions.
I planted four butterfly lavenders a year ago, but three have died back and only one is flowering. I have replanted them and feed them once a week. What now?
Lavandula stoechas subsp pedunculata (French lavender), with its silvery foliage, fragrant flowers and rose-purple bracts like butterflies, is irresistible. All lavenders thrive in poor, stony soil with plenty of sunshine. Add lots of grit to a soil-based compost, and check they are receiving enough sun. L. stoechas is more tender than other lavenders, so benefits from being wintered in a frost-free area. It will certainly be unhappy being fed. Cut your plants back (flower heads and any new growth) but avoid cutting into old wood, as this rarely produces new growth.
Thereafter, prune in mid-spring, just as new shoots are forming.
How can I protect my Melianthus in winter? Are the leaves supposed to die in the autumn?
This South African evergreen shrub is treated as a herbaceous perennial in Britain and is not reliably hardy. Planted out, Melianthus major can reach up to 2.5m, but in a container it doesn't usually exceed 1.2m and is best moved into a frost-free greenhouse over winter. In the garden, you can protect it with a mulch of bracken, bark chips or coarse compost and remove dead leaves in mid-spring. It thrives in well-drained soil in full sun. Oh, and it smells of peanuts!
We have a privet hedge running the length of our garden, but a 3ft dead patch has appeared. Growth on either side is vigorous as ever. Any ideas?
Privet (Ligustrum) is susceptible to honey fungus. The infection starts underground, and you may see honey coloured toadstools in the autumn, or black strands of fungus (known as bootlaces) in the soil. Remove the plant and burn it, making sure you dig up all the root. Replace the soil and soak the area with Armillatox (cresylic acid) to reduce the chance of re-infection. Train new growth from your healthy privet across the gap, placing a piece of green-coloured trellis there to give you privacy in the meantime.