QUESTION: I would like to grow a blueberry bush in the garden but I have chalky soil. I believe they like acid soil, so can I grow one in a pot?

ORACLE: Blueberries, varieties of Vaccinium corymbosum, make attractive shrubs for pots. Although they are deciduous they have red tinged stems and the foliage has wonderful autumn colour. Choose a large, deep pot, at least 40cm in diameter, and plant in John Innes Ericaceous Compost. This gives much better results than peat-based ericaceous compost. Feed each spring with Osmocote or Vitax Conifer and Shrub Fertiliser. Prune lightly in winter to promote side branches and preserve shape.

Although all varieties will produce fruit on their own, you tend to get a better crop if you have two or more varieties, so if you can find space for a couple of pots in a nice, sunny spot you should get a bumper crop.

QUESTION: I was given an amaryllis for Christmas which has grown and flowered beautifully. How do I keep it and get it to flower again next year?

ORACLE: Remove the faded flowers and the flower stem as soon as it starts to deteriorate. Keep the plant watered and in a light position as the leaves develop. You can feed with a weak solution of Tomorite at this stage, and throughout the growing season.

At the end of April you can stand the amaryllis outside in a sunny spot and keep it watered during the summer months. At the end of the summer the foliage should start to yellow. If it does not die down, lay the pot on its side. Before danger of frosts cut off the foliage just above the bulb. Move the plant indoors and do not water it until the flower bud emerges from the bulb. Once it does you can start to water and feed. If you follow this regime it should flower every year.

QUESTION: I have a large hebe in the garden. It has small leaves and was a nice dome-shaped shrub. Over the last year the centre of the plant has opened up to leave a hole in the middle. Can I cut it back, and will it recover?

ORACLE: Small leaved hebes, such as Hebe ‘Red Edge’, Hebe sutherlandii and Hebe albicans tend to open up in the centre as they get older. The branches get longer and eventually cannot support themselves, so they flop, leaving a hole in the centre of the plant. Take a look to see if there are green shoots emerging further down the branches – if so you can cut back to that point and the plant will rejuvenate. However it will look rather sorry for itself in the meantime. Personally I would dig it out and plant a new one! Hebes are not expensive shrubs and if you have had it for a few years I imagine you have had your money’s worth!

QUESTION: I planted a Clematis armandii against a west facing wall. It has grown vigorously but branches tend to die back. I am training it on wires, and the wall is sheltered from the wind. What is going wrong?

ORACLE: Clematis armandii is a vigorous, head-strong climber with a mind of its own – it does not like being told what to do! The strong growing shoots like to find their own way and if you try to change their direction by tying them in, they sulk and often die back. In all situations Clematis armandii, although evergreen, carries a certain amount of dead leaves. They are more noticeable because they hang on to the branches rather than falling. Plant this climber where it can do its own thing and where you do not need it to be too tidy.

QUESTION: I love lupins and delphiniums but they never seem to survive in my garden. They flower in the first year – then disappear over winter. If I try again, how can I keep them?

ORACLE: Seed raised lupins and delphiniums are rarely long-lived perennials, especially if you garden on heavy soil. In these conditions you may well have to plant every year. It helps to plant them early and to remove the flowers as soon as they have faded – cutting the plants right back to ground level! If you do this after the first flowers they often re-bloom in autumn. If you leave the seeds to develop the plant thinks it has done its job and is more likely to die. It also helps to improve the drainage by adding grit to the soil, and to mulch the soil surface with grit – this deters slugs and keeps wet off the plants.

QUESTION: I have a lemon tree which has been in the conservatory over the winter. It has produced fruit and still seems to be flowering, but the leaves look yellow and they are sticky. What is the best treatment?

ORACLE: Citrus very often look sickly in late winter and early spring. They are also prone to attack by red spider mite and brown scale. The latter clings to the leaf along the midrib on the underside, and is often difficult to spot until the leaves get sticky and covered in black sooty mould. You can spray with Provado Ultimate Bug Killer which should control the problem. However the best treatment is to move the plant outside in late April, prune it and remove the foliage, and then feed with summer citrus food or tomato food. The lemon will quickly produce new growth and flowers which should be successfully pollinated outside, and will develop into lemons which ripen in winter.