Main content

Eric Robson hosts the horticultural panel programme from West Suffolk. Bunny Guinness, Matthew Wilson and Christine Walkden answer the audience questions.

Eric Robson hosts the horticultural panel programme from West Suffolk. Bunny Guinness, Matthew Wilson and Christine Walkden answer this week's questions from the audience - including discussion of rhubarb, the best plants for garden screening, and how to correctly disperse wood ash. They also recommend the best plants for screening a garden.

Matt Biggs visits Chiswick House and Gardens to discover the story behind the recording of The Beatles' first music video in May 1966.

Produced by Dan Cocker
Assistant Producer: Laurence Bassett

A Somethin' Else production for BBC Radio 4.

Available now

43 minutes

Fact Sheet

Q. How do I look after my Rhubarb plants after I’ve finished picking them in July?

Christine – Give them a really substantial watering and then mulch heavily – 15-25cm (6-10 inches), then leave them.

Bunny – if it’s starting to flower it could be too congested and needs to be lifted out. There are new varieties which you can go on picking during the summer such as Poulton’s Pride Rhubarb


Q. Could you please identify this plant and give me some advice on its care?

Matthew – conspicuous hairy stem which gives it its name – the Stag’s horn Sumach (Rhus typhina) – produces very vibrant red flowers with great autumn colour. However, it likes to run – it sends out suckers and those can travel incredible distances – even 30/40m (100-130ft) away from the mother plant. It can be a problem in a small garden – need to be able to mow all the way around to kill off any suckers or planting it in a garden with a membrane/gravel mulch over the top.

Christine – it is a great example of right plant, right place.


Q. The scrubland behind my house has some clumps of nettles, I’ve been spraying them with weed killer in the last couple of years and last year not a single nettle appeared – why did they all suddenly vanish?

Bunny – if you get a normal garden chemical for killing nettles – usually some form of Glyphosate – that is pretty effective especially if you apply it as they label instructs. Possibly before it was washed away by rain or you didn’t dilute it to the correct proportion – or spray drift.

Q. I have a quantity of wood ash that I’m putting around my fruit trees but can I give them too much? If so what other plants would benefit from a dose of wood ash?

Matthew – I would suggest letting the wood ash store for a while – letting it mature for 6 months or a year as it can be too blunt. It might be better incorporated into some compost so it takes the intensity down another level. When you apply it directly it can start to form a cap and get slimy and quite unpleasant.

Bunny – The highest amount of compound is Lime; the pot ash amount is actually quite low. If you’re growing anything that’s an acid loving plant, then don’t put the ash anywhere near it. When you’re letting it weather down and out in the rain, all the pot ash will wash through and then you will be putting neat Lime on to the plants. When I use it I put it on in the spring to give the most benefit to the plants.

Eric – Bob Flowerdew recommends pot ash highly for the Gooseberry.

Christine – little and often is much better than a load in one go.


Q. Please could you identify this creeping nemesis? - it’s colonising plants on a north facing fence border in my small Victorian terrace garden.

Christine – I think it is ‘Mind your own business’ – it has a small leaf and can become invasive. Some people will use this specifically to give a green carpet. The difficulty is that when it’s in a border the only way to control it is by spraying it out with a weed killer – but if it’s amongst other plants, that’s a problem.

Bunny – you can get it in green, blue and gold – the green is more ubiquitous. If you’ve got bigger plants and less space, then it should go away. You can use Glyphosate – the weed killer – make sure you pull it away from other plants when you spray it. Be vigilant for a while using a mister bottle and spray it often.


Q. I’d like to know what plants the panel have seen on holiday that they would really like to grow in their garden or be able to grow?

Matthew – I love the Mediterranean in spring, before it gets dry in the heat. I would take an entire Mediterranean hillside circa 3rd/4th week of April into the 2nd/3rd week of May and have that in my garden frozen in that moment.   

Christine – China at high altitude - it would have to be Paraquilegia anemonoides – it’s an alpine and very hard to grow. Bunny – I would like big gnarled Lemon trees – most of the year there are flowers and fruit and you can use the leaves.


Q. When and how do I prune a Callicarpa ‘Profusion’? (25/30 years old)

Bunny – It’s not something you often prune; it gets to quite a large scrub – with dark blue/violet berries. You could make it more of a scene stealer and pull away/tackle the surrounding plants. Don’t remove more than a third – open it out and give a bit more light and sun to the flowers and then the berries.

Matthew – It needs quite a bit of light and air circulation to flower and have good berries. I think the reduction in berries is because it’s getting more and more congested. It is unusual to prune but in this case I would prune it by a third so take out some of the oldest largest branches completely and that will help get more air and light into it – you will lose some berries – add lots of well-rotted manure underneath, lots of water and maybe a slow release fertilizer as well. It is quite old so you could plant a new, younger one. 

  Q. My son and daughter have a small but overlooked rear garden and bungalow – can the panel recommend some planting that will grow quickly but not too large (but 15ft high), evergreen for year-round screening and interesting in leaf flower and or colour? Preferably low maintenance as a bonus.

Christine - Nandina domestica – it’s an evergreen, beautifully divided foliage, produces nice plumes of feathery white foliage, which are followed by red berries which attain a height and width of about 5ft and doesn’t need much work.

Matthew – Pleached Photinias or the Photinia ‘Red Robin’ – in pleached (clear stem to the tree-like plant and the branches above are trained horizontally) form it works well. You can buy them as pre-formed pleached plants – not cheap (10-15 years old) – effectively an aerial hedge.

Bunny – It’s worth getting some canes and working out the exact position and height that they will need to be – you can get other pleached evergreens such as Holly (Nellie Stevens), Magnolias and oaks. You could buy smaller younger ones and grow them up and train them along the fence yourself.


Q. I have an old bath, 58 inches by 22 inches, I’m thinking of using it to grow cranberries and Sarracenias (Pitcher plants). If the panel think this is feasible please could they advise on siting and cultivation, if not could they suggest alternative planting?

Matthew – You could definitely do that but the more typical plant for baths is blueberries.

Bunny – I would partially restrict the plughole – to retain the water put some fleece over it to stop the flow.

Christine – Sarracenias need boggy, acid conditions. Aesthetically it’s not unlike what you would see with the Vacciniums (blueberries) in their natural conditions. It could be a very interesting combination. In the spring you need to watch out for slugs and snails going for the early growth because they do really love Sarracenias – a small amount of copper around the bath might help with this. 


Six of GQT’s naughtiest gardening innuendos

Six of GQT’s naughtiest gardening innuendos

When Gardeners' Question Time got mucky.