Thorny problems: ailing magnolia and suffering cyclamen The tree would also probably appreciate a dose of ericaceous shrub fertiliser and a hefty dollop of leaf mould this spring. Treated kindly, it should reward you with a happier demeanour, better growth and in due course, more flowers. I'll keep my fingers crossed. Cyclamen let-down I was given a potted cyclamen in full bloom for Christmas and the only information on the label is "Fabulous fragrant cyclamen in a wide colour range, excellent in patio containers and hanging baskets. Flowering time late summer onwards. Suitable for full sun or partial shade. Deadhead to prolong flowering. This implies they are hardy. Kept indoors in the warm (I live in northern Scotland), the flowers drooped and fell off. What was I supposed to have done, and what now? Ruth Wood, via email This kind of labelling makes me see red (see also "It's all in the name," right). You were had, Ruth. These pretty little flowering cyclamen (I believe they are hybrids of C. persicum) are sold to us by the squillion in early winter, and will indeed flower though exceptionally mild winters outside in containers in sheltered urban southern courtyards. After a very short time in the dry atmosphere of centrally heated houses, however, they go downhill. They look like the real thing - UK-tolerant outdoor C. coum and C. hederifolium - but hardy they ain't. My advice? Give up. Annual report Not a problem at all, but I am bending the rules because the weather has been vile and we all need to set our sights on summer. So thank you, Vivienne Kirk from Belfast, who last year grew Ammi majus - a delicate annual relation of perennial cow parsley - from seed, adored it, bragged about it to her friends and sent me a picture taken of her border last summer stuffed with it. The photo brightened what was otherwise a dreary day, the hideous remnants of slowly melting snow marring the otherwise pleasing garden view from my desk. I love Ammi and another cow parsley relation, Orlaya, but they are not the easiest annuals to grow (certainly the latter only really makes a good summer plant if seed is germinated under glass the previous autumn). A big fan of white-flowered umbels (which seems now to be the smart way to refer to members of the plant family Umbelliferae), I love sweet cicely (Myrrhis odorata) too and have even been known to let cow parsley seed around to a degree. Both of these look classy growing informally in dappled shade among stripy hostas (H. sieboldiana, formerly 'Frances Williams") and the best white astrantias (A. major 'Shaggy"). And now I grow another perennial from the same family, Cenolophium denudatum. It flowers later and for longer than the other two and has slightly more robust and shiny foliage. It looks elegant around white phlox and I thoroughly recommend that anyone with the space for a spread of Macleaya plonks some plants of Cenolophium in among it to provide a dramatic contrast. Beth Chatto's nursery, bethchattoshop.co.uk, has plants of Cenolophium. Write to Thorny Problems at helen.yemm@telegraph.co.uk or Gardening, The Daily Telegraph, 111 Buckingham Palace Road, London SW1W 0DT. Helen Yemm can answer questions only through this column. The week ahead Cut back lavender Take the shears to established lavender, but don't cut them back into old wood (i.e. not below the lowest visible silvery sprouting leaves). Trim dogwood Cut back all or at least some of the stems of Cornus alba to encourage more stems to grow from the base during the coming season. Prune deadwood Prune dead or damaged wood from dormant shrubs and small trees that are prone to dieback, such as ornamental acers and Spartium junceum. Snip hydrangea Remove the papery remains of last year's flower heads from climbing hydrangeas before they annoy you by blowing all over the garden. Perennial clean-up Clean the bases of evergreen perennials such as golden oats (Stipa gigantea) by cutting out old flower stems and browning foliage.