Thorny problems: honey fungus (Filed: 12/01/2002)

Helen Yemm answers questions about holly, moles and garden mirrors

Honey fungus

The privet hedge that separates me from my neighbours has started to die. I have also recently seen orangey brown toadstools at the base of one of the plants, on various much-loved trees and shrubs in my garden (part of which was once a cherry orchard) and in my neighbour's lawn, where there is an old tree stump. I am told that this is honey fungus. Must I really dig everything up, sterilise the soil and start again? Eunice Doswell, Tonbridge, Kent

HONEY fungus toadstools are an indication of the problem, but it actually spreads unseen from "host" plants, usually old tree stumps, via underground rhizomorphs (the "bootlaces" often described). There are numerous strains of the fungus, of varying "potency", that attack and kill many woody plants and frequently home in on sick ones. Privet is particularly susceptible.

Feed your trees and shrubs to encourage strong growth, remove dead and dying ones promptly, with as much root and surrounding soil as you can, and replace them with plants from the RHS's helpful list of more resistant species. Once it has taken hold, you are unlikely to beat honey fungus into submission, so you just have to learn to garden alongside it. If you think how extensive the roots of a large old tree must be, stump removal (by grinding or digging), while advisable, only touches the tip of the iceberg. (John Cockrem, from Devizes in Wiltshire, this applies to you and your privet hedge as well.)

Holly berries

We have learnt that our Golden King holly is not self-pollinating, and therefore has no berries. Can you recommend another compact holly (to grow in a tub), preferably with smooth leaves that would make a suitable mate for it? Majorie Clegg, Ribble Valley

Someone in the holly-naming department got things a little cock-eyed. Ilex altaclerensis 'Golden King' is female, while the other well-known variegated holly, I. aquifolium 'Silver Queen' (with prickly leaves), is male. As you realise, in order to get holly berries you need a male and a female plant in close proximity unless your single plant is self-pollinating. Your choice is limited.

Many male hollies are too large to grow in tubs and most have spiny or toothed leaves. You could seek out a compact self-pollinating female such as I. aquifolium 'J C van Tol', which has smooth, dark-green leaves and produces lots of red berries by itself - and may do the trick for your 'Golden King' into the bargain.

Mirror, mirror

Richard Burn from Chelsea, also emailer Linnie Reeve, contacted me ages ago about mirrors suitable for use outdoors. It has taken me this long to find an answer. Apparently, you can take your mirror to a glazier who will cover the back with lead foil - which costs about £1 per square foot. This should make it weatherproof.

Keith Judge from Rugby needs a replacement pair of Derri Boots and wonders whether they are still made. My local agricultural supply people Scats, in Heathfield, Sussex (part of a 20-strong chain in the south of England) say they still sell these tough gardening boots, but now call them Guy Boots. I am sure there must be similar places that sell them further north.

More mole matters

Animal passions seem to have been stirred up again following the recent letter about the problem of moles.

Several readers reported eventual success with sonic mole scarers, but Shiela Edgar found a cheaper solution: children's windmills stuck in each molehill set up vibrations that her moles found intolerable. Windmills presumably work on a similar principal as the empty bottles buried up to their necks that I mentioned. A less visible method worked for Ken Brown. He shoves his hose in the last hill of a run and leaves it running for 45 minutes. Again, using a hosepipe, A J I Jennings suggests that gardeners with smelly old petrol mowers should direct the exhaust fumes into the mole runs.

Some readers use traditional traps, but all wanted to remain anonymous. Traditional deterrents were generally scoffed at. An unusual idea came from D Lipton, who suggests placing fresh ferret droppings in the runs.

There is a website with some useful information on moles and mole trapping - including the latest thing, "live" mole traps - www.Trap-Man.com.

Ballota

Help! After its first year my ballota looks a mess, and is far too big for the sunny space I have given it. Should I cut it back now or will this kill it? Jenny Parkin, Poole, Dorset

Woolly-leafed Ballota pseudictamnus, from the scrubby hills of the Mediterranean, can get a little out of hand in our climate. When I first grew it I fiddled around with mine, cutting bits off it at various times of year. I have now come to the conclusion that the best treatment is to cut it back to the bone in August. It will immediately make a little bit of growth before the autumn sets in, making a pleasant, neat, silvery-green hummock for the winter. It will then flower in mid-summer for several weeks, still in a relatively orderly fashion. You can whack it back again in August. And don't feed it - it will become more compact if it is made to go hungry.

Write to Thorny Problems at helenyemm1@aol.com or Gardening, The Daily Telegraph, 1 Canada Square, London E14 5DT. Helen can answer queries only through this column.

-- Anonymous, January 13, 2002