Kim Wilde answers your gardening questions.
We have a 'gladey' garden that until recently was fringed by leylandii on the boundary with our neighbour. This has now been replaced by a fence. How can we hide the fence while our new trees and shrubs grow?
Firstly, the soil where the leylandii has been will need improving with organic matter (well-rotted manure). This will get your plants off to a flying start. One of the earliest and fastest climbers in my garden is Humulus lupulus ' Aureus', the golden-leaved hop, which can be easily trained along wires attached to the fence panels. It colours best in full sun. The aspect of the fence will dictate the choice of plants, so do check. Solanum crispum ' Glasnevin' has fragrant violet flowers, and is semi-evergreen, but will need a sunny position. Bare fences can be softened with a lick of green paint, but do consult your neighbour first.
Our pond is covered with duckweed that chokes the water lilies. What can we do?
High nitrate and phosphate levels encourage duckweed ( Lemna ). To reduce these, pull up the Lemna , then encourage a more varied planting scheme, including submerged (for example, Elodea crispa ) and marginal plants (for example, Caltha palustris ) as well as floating ones (such as lilies or water hyacinths). Plant leaves should cover a third to half of the pond's surface. A long-term solution is to put in submerged oxygenating plants and algae-consuming fish. Avoid ducks: they destroy plants. For information, call The Ponds Conservation Trust, 01865 483249.
My downstairs neighbours are building an extension. How do I plant up a green roof, to improve the view?
A green roof system consists of four basic layers: growing plants, a lightweight growing medium (for example, composted bark), a drainage layer (for example, pea gravel) and a waterproof layer (for example, asphalt). Possible plants include drought-tolerant sedums and Nepeta x faassenii and grasses. It's essential to prepare the supporting surface, so consult an expert, such as Blackdown Horticultural Consultants, 01460 234582.