This week the team visits the East Malling Research Centre in Kent, with Eric Robson in the chair. Matthew Wilson, Bob Flowerdew and Christine Walkden are on the panel taking local gardeners' questions.
Produced by Howard Shannon.
A Somethin' Else production for BBC Radio 4.
Q. I have a north-facing border, approx. 1.5m x 10m in size and with alkaline soil. What floriferous shrubs or perennials would the panel recommend for maximum interest?
A. Herbaceous plants may be better in the long run, as they will maintain their smaller size. Delphiniums, Lupins, Phlox and Peonies are recommended, as are dwarf shrubs such as Sorbuses (e.g. Sorbus fruticosa), Virburnums (e.g. Viburnum opulus 'Compactum', the compact Guelder rose), Spireas, Cornuses and Kerria japonica. Woodland plants such as Hellebores or Pulmonarias (e.g. 'Mawson's Blue') would do well in the north-facing conditions.
Q. I would like to move and divide a Peony but have been told it is not a good idea. Can I do this and, if so, when?
A. Now! If the buds are up and you can see a nose, water well the night before and then lift as much of the root ball as possible. Slice this, and let the cut surface dry before replanting. Treat it like any other herbaceous perennial, much as you would with Hostas at this time of the year.
Q. What can I do to slow the growth of the Dawn Redwood at the bottom of my garden?
A. No-one likes to fell a tree, but it may have to go. Check that it does not have a Tree Preservation Order placed on it.
Q. What novelty fruit would the panel like to see developed?
A. A reasonably hardy Fuchsia with a juicy, sweet berry developed for the crop - Fuchsia California Dreamers produce large, sweet berries. A square banana with a tough skin, that wouldn't get damaged in your rucksack. A fig crossed with a melon (a felon), a fig crossed with a mango (a fandango) or a fig crossed with a melon, a strawberry, a grape, a raspberry, a kiwifruit and a pomegranate - a fruit salad.
Q. There is an Osmanthus 'Gulftide' shrub near our house. Almost every leaf on the bush is being eaten, though there is no sign of anything on the bush. Could the panel advise as to what is doing the damage?
A. The damage shown on the leaves of this plant is typical of the adult vine weevil, which takes semicircular bites from around the edge of the leaf. It is unusual for vine weevil to target a plant with such a thick, leathery leaf. There are nematodes available for tackling vine weevil, but you would need to wait for soil and air temperature to warm up a little.
Q. I have a Prunus x subhirtella 'Autumnalis' which is grafted onto a rootstock. The rootstock throws up suckers up to 30ft away from the tree. What is the best way to deal with the suckers?
A. There are two options. Firstly, regular cutting would stop you noticing them. Alternatively, go to where they are, find the root and remove the shoot - be careful not to leave any of the shoot remaining, as any remaining shoot will return. At 30ft from the tree it would be safe to cut the root.
Q. I have a small pond, approx. 70cm x 60cm, which has two shelves for shallow water plants. What plants - preferably those which are good for wildlife - would the panel recommend?
A. Blackcurrants are bog plants and will grow (though stay small) with their roots entirely submerged in 6in to a foot of water, providing a ladder for dragonfly larvae to climb out of the water. The dwarf Nymphaeas would grow well, as would the dwarf form of Pontederia cordata or various other dwarf aquatic plants. Caltha palustris (marsh marigold) is early flowering and as such a good source of pollen and nectar, and Butomus umbellatus (flowering rush) would also be good for wildlife.
Q. What plant would the panel like on their grave and why?
A. Something sweet-smelling such as Daphne odora 'Aureomarginata'. Soldanella hungarica, which is delicate but tenacious. Kelp - for a sea burial!