Reader Queries:

Q: I have an old clump of agapanthus ‘Bressingham Blue’ growing in a hot dry border. It used to be covered in flowers but now it seems to flower less every year. Should I divide it or feed it? — Mrs K. Reynolds, London SW6

A: This is a tough and deciduous variety of agapanthus with dark blue flowers at about 80-90cm (31-35in). But much as agapanthus like heat they are not indestructible. In really dry soils they can stall, and in soils which are too poor they can be starved into flowering less. However, the sheer age of the clump can also cause them to stall. For proof, look at your clump and see if the new shoots seem stronger round the outside where the soil is fresher. Better to divide than feed.

Lift the clump with a fork now. There will be a great wrenching of fat white roots, but it will come. Then, taking care not to break the emerging shoots, place the clump on its side and with a handfork crack off smaller clumps the size of your fist. You may find that the roots have piggy-backed each other and that the clumps are packed beneath with old rhizome; break this away to leave just the younger surface growth. Then trim the roots to around 15cm and replant in fresh soil.

Q: The flower beds in my garden were filled with large daffodils by the previous owners. The leaves grow shabby as they die off, and smother other plants. I would like to move them out of the beds altogether and replant them under a birch tree on the edge of our property. Is it possible to move them now? - H.D. Simpson, Aldershot, Hampshire

A: By all means move them now — it is pretty well impossible to kill daffodils. However, disturbing them now will mean that the foliage will die away quickly, meaning that the bulbs will be weak next year and may not flower. If that matters to you, lift the clumps intact, and water them well after replanting. If you are prepared to have a year or two with few flowers, then take this chance to divide the clumps and spread the bulbs more thinly and naturally.

Q: Seven years ago we inherited a huge garden from my parents-in-law. We decided one vegetable garden was enough, so I let the other one become a wild garden, which used to look wonderful in summer. Unfortunately, it has become overtaken with white Michaelmas daisies, and we can’t get rid of them. I would like to keep some, but they are hard to dig up. We’re organic so can’t use sprays. Any suggestions? - Mrs C. Bentley, Hay-on-Wye, Herefordshire

A: Even if the things were dead, whether you used an organic or a synthetic herbicide, you would still have to get the roots out. If the area is one solid mass of roots from end to end, hire a rotovator and chomp through the lot fairly shallowly — just enough to get under the crowns, about 4-5in. Go through it with a fork a couple of times to fish out the pieces, then you can dig it or rotovate it more thoroughly. Put the roots in a heap to rot down slowly, or pile them on the embers of a big bonfire.

Q: I have an upright juniper in my garden, which my mother planted 20 years ago. It is starting to break up and some of the branches have fallen outwards. Can I save it or does it have to go? - Mrs R. Landford, Colne, Lancs

A: Sadly, this happens to most narrow conifers as they age, from wind or the weight of rain or snow; eg, your Irish juniper (juniperus communis ‘Hibernica'), Italian cypresses (cupressus sempervirens) and the blue-grey Arizona cypress (cupressus arizonica). There are three choices for you. One is to tie in the wayward branches to the central trunk, but if the ties break after that, the branches will fall out and be irreparably sprained (old tights seem to last for ever as ties). Or you can cut out the wayward branches and leave their neighbours to fill the brown gap — not the prettiest solution. Lastly, you can fell the tree. If it's very shabby and it's likely that more branches will splay, then probably its moment has come.

Q: My very large terracotta pots have cracked and some of the rims have broken off, due to the weather. Can I glue back the pieces, fill the cracks, and the whole pot then be painted? I cannot remove the contents as they are too heavy and I feel the pots would totally disintegrate. - Mrs K. Wakeman, Alton, Hants

A: It's heart-breaking when much-loved pots perish; to avoid that, one must keep them empty and dry, and frost-free over winter. But any heavy, permanent planting bursts pots in the end.

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