Make the move
Q How can I encourage my wellestablished peony to flower? PETER BIDE, TEDDINGTON
A Your peony looks quite healthy but it is planted in dense shade and will never flower in such a shady spot. If you want it to bloom, you must move it into a place that gets sun for at least half the day. As soon as the leaves start to turn red, in October or November, carefully dig it up and replant it in a sunnier spot. Peonies move perfectly well but try to avoid damaging the thick roots. When you replant it, make sure the top of the crown, where the shoots grow from the roots, is no more than 2.5cm (1in) below the soil surface. Deep planting is another reason why peonies might fail to bloom. It will take at least a year for the peony to build up strength to bloom so do not expect flowers next year.
Q What will grow in a 15x2ft raised bed that’s in shade for half the day? SEAN KEEVEY, VIA WEBSITE
A A position in half shade is fine for most plants. Your choice will really depend on the soil you put in and what plants you like. Small plants would be best as the bed is quite narrow and will be dry in summer unless you water a lot. Shrubby herbs, tough alpines and spreading pinks, violas and helianthemums would all work and you could add bedding plants such as nemesias.
Q Is there hope for poorly trachelospermum potted in ericaceous compost? TESS PRITCHARD, BY EMAIL
A I’m not sure how long the plants have been in the pots but if you used ericaceous compost it may have been made of peat or recycled material, not loam, which won’t be good in the long term. Trachelospermum do not need acid compost. I suspect that the plants are or have been, very dry and may need more feeding. They would benefit from being planted in the garden or repotting into larger pots using loam-based compost such as John Innes No 3.
HEDGING Q What soil pest is damaging our laurel hedge? The leaves are full of holes! ALAN ROEBUCK, BY EMAIL
A It’s unlikely that soil pests are eating your laurel hedge. Vine weevil adults may nibble the leaf edges but powdery mildew is the more likely cause. Although the early stage of the disease is a white, powdery coating on the leaves, later the areas turn brown and drop out so holes appear, which looks like something has eaten them. Spraying is not usually practical so it’s best to trim the hedge to remove the affected areas. Mildew is always worse on plants suffering from drought or lack of nutrients, so feed or mulch the hedge in spring to improve its health.
Q Can I propagate from alder hedge to replace dead parts? CLIVE BALAAM, BY EMAIL
A Alnus glutinosa, native alder is a good choice in wet soils, where it will thrive even in water. It is hardy and easy but is prone to a form of phytophthora that kills odd branches on trees and causes ‘bleeding’ of sap at the base of the tree. It is rarely fatal and trees can be affected and still grow for many years. There is not much that you can do to control it and, as you say, they often sprout from the base if cut back. Trees also naturally seed around and you might find seedlings. Alternatively you can root hardwood cuttings taken in autumn by pushing them into the soil where you want them to grow.