Kim Wilde answers your gardening questions.
We have just laid a new concrete drive, leaving two planting holes (16in x 8in), on either side of our south-facing front door. What do you suggest for climbers to grow around the door (I would prefer evergreens)? The soil is fairly neutral - hydrangeas in it grow pink.
Too much evergreen foliage can be oppressive. So why not partner an evergreen with a deciduous climber? South-facing walls are warm and sheltered. Take advantage of this and plant the vigorous evergreen climber Trachelospermum jasminoides: it has creamy-white, exquisitely scented flowers from mid-to-late summer. Call me old-fashioned, but I am a sucker (forgive the pun) for a climbing rose round the front door. Try the scented Rosa Iceberg, which is deciduous but has glossy leaves and abundant white flowers all summer. Add slow-release fertiliser and dig in lots of organic matter, as the soil at the foot of a wall is usually dry. Stout galvanised wires fixed securely 5cm-7cm from the wall, allow air to flow and keep fungal diseases to a minimum.
Part of our garden is on a 40-degree slope. It's too big to terrace, so we want to plant something to stop the the soil (a light boulder clay) from slipping downhill. Can you suggest suitable, and colourful, plants or shrubs?
Steep slopes can have poor soil conditions, so add well-rotted manure or compost before planting, plus a general fertiliser before mulching in spring, to save summer moisture. Plant through coarse coconut matting (which will rot away), to prevent the soil from slipping. Hi-Tex UK supplies coir matting mesh (01233 720097). The deciduous Cotoneaster horizontalis (above right) is good for clothing slopes; its glossy leaves turn fiery red in autumn, when clusters of berries appear. Its evergreen relative C. dammeri is a good ground hugger, too. For colour, try fast-growing Hypericum calycinum (Rose of Sharon): it has yellow flowers from early summer to autumn (below left). Or maybe a ground-cover rose such as Rosa Bonica, which is pink and long-flowering, and would sprawl down your sloping bank. Climbers such as Lonicera japonica, Parthenocissus quinquefolia and wisteria all grow flat along the ground without support.
I have a yellow canna lily, which was in flower when I bought it a couple of months ago. The flowers lasted a few weeks, and then a small crusty ball appeared and the leaves turned brown at the edges. Yet, to my amazement, this week the plant has started to flower again! But there are still brown leaves. How should I look after it?
In frost-free areas, cannas can be left in the ground in the autumn, covered with a straw mulch for protection; otherwise dig them up after the first frost, leave them to dry for a few days, trim off any dead growth, then store in an old container filled with bark chippings over winter. (Remember to label them!) Plant tubers in spring in pots of general potting compost, and keep them warm (ie, in the airing cupboard), but don't let them dry out. When shoots appear, move them to the windowsill, until planting out when all risk of frost is over. Apply well-rotted manure on planting to keep them happy.