e-mail Jane Owen with your gardening questions: jane.owen1@timesonline.co.uk

We were one of those hit by a flash flood on Friday morning, long before all the flood warning were issued. The water’s gone but our newly-planted garden is covered with a layer of mud up to half a metre. We planted hedges, shrubs, a herb garden, a herbaceous border and a salad garden. Can you suggest a way to increase the garden’s chances of a full recovery please? Marie Jupe, Berks

So long as your soil doesn’t have drainage problems I reckon your garden will be fine although any newly-sown salad seed will have been washed away. Rain will eventually get rid of the mud on the foliage. You must be relieved to have survived the floods without too many problems given the catastrophe facing those in places like Tewkesbury.

Our pond is three years old and has plenty of wildlife but some of the aerating weed seems to float on the surface and die. Matt Chambers, Cornwall

Some aerating weed is supposed to be planted into gravel-topped planters rather than be allowed to float freely in the water. If your aerating weed is one of the following you need to plant it in order to avoid problems:

Horn-wort Ceratophyllum demersum

Water Milfoil M. verticillatum or Myriophyllum spicatum

Curled Pondweed Potamogeton crispus

Perfoliate Pondweed Potamogeton perfoliatus

Horned Pondweed Zannichellia palustris

I bought some Giant Allium at the Malvern Show but they have not come up. Prinny Buckingham, Somerset

It’s a great idea to buy from a specialist at the show BUT you need to follow their instructions. Giant Allium needs to be planted out in the autumn and kept in a cool, dry place until then.

Lily beetle continues to destroy the 50 or so lilies we have in pots through our garden despite picking them off as you suggest. Please can you suggest a more effective method? Malcolm Sage, Brighton

It really is the most effective method but you have to keep doing it. The alternative is to use an insecticide like imidacloprid but, as far as I can make out, spraying doesn’t have much affect on the adult beetles and, in order for it to kill off the ghastly slimeball grubs, you have to spray underneath each lily leaf – which is where the grubs can usually be found. This is quite an undertaking and you might as well squash the beasts manually in the time it takes to spray. For the latest on this disgusting pest have a look at Pontus Wallsten and Andrew Salisbury’s slightly eccentric video clip http://rhslilygroup.org/videopage.htm . Andrew is probably the world’s foremost lily beetle expert. Incidentally, did you know that the slime that covers the grubs is their own excrement? Ghastly.

I am in the process of transforming my small walled garden into a more modern space. To do this I created some weatherproof canvases which look great (I am starting to sell them http://www.cheekymojito.com/about.php) but I think they may need planting around them. Robin Upshon, Bournemouth.

I can see that your canvases would look even better with some planting. In small spaces like your garden I’d have thought an evergreen climber is the best bet. It would have to be trained on wires and trimmed regularly. How about the lovely sweetly scented Trachelospermum jasminoides or a clematis like one of these www.saska.demon.co.uk If your courtyard is frost free and warm you may be able to use the lovely pinky-red Red Banana passionflower Passiflora antioquiensis.

Please give a judgement on a domestic difference of opinion which is causing chilly silence at every mealtime. Over the weekend we sorted out our irises. I have seen iris in RHS gardens having their leaves cut neatly to an inch or so. I started to do this when Her Indoors threatened to use my secateurs on my most sensitive part should I continue. She says leaves have to be left in tact. Verdict please. Name and address withheld

I am relieved to say that you are both right. Most of the time Iris leaves need to be left alone no matter how untidy they look. However, when dividing and replanting iris, the leaves need to be cut as you describe so that the newly-planted specimens don’t get rocked by the wind.

Is there any source of very cheap yew hedging please? We are making a garden from a field and want to give it shelter and a beautiful backdrop of yew. Money is very very tight. Cathy Wilkinson (no address supplied)

Take cuttings – right now until the end of August. Use half-ripe (soft at one end, woody at the other) terminal shoots and cut them back to about 8cm long. Some people reckon you should dip one end in hormone rooting powder but I never bother. Either way push the cuttings into pots/trays of fast-draining potting compost (start by putting several cuttings in every pot/tray). Water with a fungicide and put the cuttings in a shaded cold frame. If you don’t have a frame, put a loose, pierced layer of polythene over each pot/tray making sure the polythene does not touch the cuttings and place the pots/trays on a north-facing window sill.

Is there any way of avoiding blackfly on broad beans? Mine are covered. Name and address withheld

The classic way is to try to get ahead of the blackfly by sowing in autumn so they appear before the aphids. Another good strategy is to pinch out the tender young growth when the plants are in flower. I rarely remember to sow in autumn and have found that planting broad beans in amongst other plants seems to avoid the blackfly problem altogether. At the moment my broad beans are juxtaposed with Eucomis, salvia, Nicotiana, chives and Angels’ fishing rods. It looks odd but it seems to do the trick.

e-mail Jane Owen with your gardening questions: jane.owen1@timesonline.co.uk

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