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Eric Robson and the panel are in Liverpool. Bunny Guinness, Pippa Greenwood and Bob Flowerdew answer this week's questions.

Eric Robson and the panel are in Liverpool. Bunny Guinness, Pippa Greenwood and Bob Flowerdew answer this week's questions.

The panellists offer advice to a man with an 8ft cactus growing in his greenhouse, diagnose an ailing Cosmos crop and debate the best way to rid an allotment of ants.

Questioners also grill them on baking apple trees, mare's tail, therapeutic plants and how best to grow okra in the UK.

Matt Biggs visits Wanstead Flats in East London to meet garden designer Jonathan Snow and discuss the effects of fire on plants.

A Somethin' Else production for BBC Radio 4.

Available now

43 minutes

Fact Sheet

Q – What can I do with my 8ft (2.5m) cactus? 

 

Bunny – Buy a bigger greenhouse?

 

Pippa – Give it to a botanic garden

 

Bob – Turn it through 90 degrees and let it grow horizontally.  The end will then turn up.

 

Q – Every year we successfully grow Cosmos from seed but this year we haven’t had any flowers.  The root systems look fine.  What might have gone wrong?

 

Pippa – It could be to do with high nitrogen levels.  You could put sulphate of potash into the soil. 

 

Bunny – I think it will be down to poor seeds

 

Q – I have a Canna (Canna tropicanna) growing in a pot that is getting quite crowded.  When is the best time to divide it?

 

Bunny – Early spring.  Just before the little shoots come up.  Should be pretty easy.

 

Q – How do we get rid of the vicious ants that live on our allotment?

 

Pippa – I would use nematodes as they will irritate the ants

 

Bob – Boiling water.  Or you could farm them. 

 

Bunny – Feed them oats

 

Q – I inherited a mature baking apple tree.  Over the last two years it has flowered and fruited less than before.  Can I prune it?

 

Bob – You can prune out dead, congested wood.  But cooking apples can go into what’s called biennial bearing where they have a heavy crop one year and little the next.  Try giving it some wood ash.  Make sure to thin out as well; you get fewer but better apples.

 

Bunny – Give the base a good mulch

 

Q – When I clear land of weeds lots of mare’s tail crops up.  Should I just leave the weeds be?

 

Bunny – There’s a chemical called Ammonium Glufosinate which is very effective. 

 

Bob – With Equisetum and Great White Bindweed you’ll be able to kill off what you can see but they spread further than you can see so they will be back. 

 

Q – I have a Bird of Paradise (Strelitzia reginae) and the tips of the leaves are going brown and crispy.  Why?

 

Pippa – Too dry, too wet, too windy, too sunny; any of those could be the culprit.  If the majority of the leaf is green then I wouldn’t worry too much.  Do check you haven’t got Red Spider Mite though.  Try and increase the humidity.

 

 

Q – What therapeutic plants would you plant and why?

 

Bob – The old-fashioned herbs, especially Hyssop.  Kale is very nutritious.  Watercress if possible.  Goji berries are good but don’t taste very nice.  Red fruits are full of vitamins and anthocyanins. 

 

Bunny – Make it as green as possible – apple trees, bay trees, honeysuckle.  Daphnes are great for scent.  The best drinking herb is Lemon Verbena. 

 

Pippa – Try and get a water source in there to encourage lots of wildlife. 

 

Q – I want to grow okra in Manchester but I’m getting bad results.  What can I do?

 

Pippa – The main limiting factor is light so try and create a shelter (for warmth) but letting in lots of light then you might succeed.

 

Bob – Poorer soil is better for them.  You need to grow a lot of plants to get a decent crop.  Water well but never feed them.

 

Bunny – Invest in some LED lights. 

 

 

 

 

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