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Postbag Edition

Eric Robson hosts a postbag edition of the programme from Garden Organic in Coventry. He is joined by Pippa Greenwood, Matthew Wilson and Bob Flowerdew.

Produced by Howard Shannon
Assistant Producer: Hannah Newton
A Somethin' Else production for 麻豆社 Radio 4.

Available now

43 minutes

Last on

Sun 28 Jun 2015 14:00

Questions and Answers

Q 鈥� 15 years ago I planted a Silver Birch that grew well but then started to fade away.聽 At the base I saw something that looked like Honey Fungus.聽 Last year, convinced the tree was dead, I took out the trunk with a mattock and removed any signs of fungus before planting another Silver Birch five yards (4.5m) away.聽 The Pyracantha hedge has now started to die off at the end nearest the infection.聽 What can I do beyond taking out more and more plants?

Pippa 鈥� Silver Birch are very prone to Honey Fungus.聽 Five metres is very close though.聽 Also, Honey Fungus stays underground from year to year.聽 Five years is approx. to five yards away (the fungus moves at about a yard/metre per year) if you鈥檙e talking about the bootlace growth.聽 So planting much further away would help as well as setting up a cordon.聽 Take out the dead and dying plants as well as the plants about 2 metres further away for good measure.

Q 鈥� I bought an Azalea in Woolworths for half a crown in 1965 鈥� it鈥檚 got now bigger since I planted it鈥� what am I doing wrong?

Bob 鈥� Some Azaleas are very small 鈥� it could just be one of the dwarf ones.聽 Plants that can鈥檛 flower grow until the can flower 鈥� if this is flowering happily where it is I wouldn鈥檛 worry about it.聽

Matthew 鈥� It鈥檚 obviously quite happy there but if it looks a bit lost I would pop it in a pot and almost treat it like a bonsai鈥� although then it might start growing like the clappers!

Q 鈥� I鈥檝e recently bought a polytunnel which is 15ft x 10ft (approx. 4.5m x 3m) and my grandson suggested I try to grow some grapes.聽 What soil type should I use and what variety of grapes would be best?

Bob Sherman (ret. Chief Horticultural Officer at Garden Organic) 鈥� It鈥檚 a good sized space.聽 There are really three types of grapes 鈥� ones for making wine (venus), also Sweetwater, and Muscat grapes which have much better flavour.聽 The best ones are the Muscats 鈥� Cannon Hall Muscat, Hamburg Muscat.聽 Grapes are vigorous so you need to train it well in the polytunnel.聽

Bob F 鈥� Or you could try the Madresfield Court variety鈥� I wouldn鈥檛 plant it in the ground 鈥� try tub growing - bringing them in in February - you get an earlier crop 鈥� about five or six bunches per vine but then you can get a vine to every square metre.聽 This will contain them as they can be as vigorous as a wisteria!聽

Q 鈥� As a member of the RAF my family and I move every two years 鈥� we usually inherit poorly maintained gardens with poor soil quality.聽 We鈥檝e just moved to Suffolk, with a bright back garden, and there鈥檚 a large (10m x 2m/33ft x 6.5ft), knee deep in weeds, partially under a Sycamore tree鈥� what would the panel suggest I could do to get quick results?

Pippa 鈥� Thorough weeding is vital.聽 Make sure the Sycamore isn鈥檛 taking up too much root space/offering too much shade 鈥� set to it in a mean way!聽 Plant-wise 鈥� go for annuals, but also perennial bulbs.

If you were staying in the UK with your next move you could grow some small shrubs to take with you.聽 Also, use some of the bed for vegetables 鈥� you could still, this year, grow some veg from scratch.

Matthew 鈥� I would go for perennials that won鈥檛 need too much aftercare and can be moved in two years鈥� time.聽 Things like 鈥� Persicaria Firetail which is very robust, also Stipa gigantea, the Golden Oat Grass.聽 Perennial Geraniums too would be good 鈥� something such as one of the endresii hyrbrids.

Bob Sherman 鈥� I would focus on annuals and some vegetables.聽 Some veg is very colourful like the Chicories and the coloured lettuces and beetroot, ornamental cabbages and cauliflowers.聽

Q - I planted a bramley apple tree last year from a supermarket. Its main stem is about 3ft and has 4 branches which are all about 3ft long. They are all at this time flowering beautifully. The thing is, should I have cut these back? They are far too thin to bare fruit so do need pruning. How much do I cut them back and when is the best time to do it? This tree is on my allotment in Scarborough.

Bob Sherman 鈥� From a supermarket it鈥檚 probably a dwarfing or semi-dwarfing rootstock鈥� something like a M9 or M106鈥� hopefully it鈥檚 not on M25 because that will probably outgrow your house!聽 You don鈥檛 want it to fruit this year; it鈥檚 too young.聽 Come winter, cut the four branches back by about half then next year you should be able to pick about 6, even-sized branches.

Bob F 鈥� Get another apple tree 鈥� a Bramley will never fruit on its own.聽 Or other apples, a Crabapple will certainly pollenate it.聽 Ideally prune it back but if it is a dwarfing tree I leave it alone as they offer so little growth.聽 Maybe use canes to hold the weak branches into a framework.

Pippa 鈥� When buying you want a stock that has come in recently, you want to buy it before it has broken into leaf (or only just started), at the bottom end the roots need to have some moisture too.聽

Q 鈥� My Pittosporum has become large and unkempt, can it be used for topiary? I want to make it into a spiral.聽 It鈥檚 3 years old, 4ft high and 3ft wide (1.2m x 0.9m approx.).

Matthew 鈥� You can use them for topiaries, yes, but I wouldn鈥檛 go as far as a spiral.聽 Some plants can stand that level 鈥� Taxus baccata the yew is one, Buxus (Boxwood) is another 鈥� but Pittosporum 飞辞耻濒诲苍鈥檛.

Sally Cunningham from Garden Organic 鈥� I would leave it alone. Let the cold winter cut it back for you.

Q 鈥� My Salvia 鈥楬ot Lips鈥� has lost its bicolour and is only flowering red, what can I do?

Matthew 鈥� It does this the Salvia 鈥楬ot Lips鈥� 鈥� it goes through funny phases (it is technically a perennial though it is grown as an annual). It is unstable.

Sally 鈥� It might be to do with temperature, moisture, and day-length.聽 If they are kept moist they tend to be more bicolour and if it鈥檚 cold they go red!

Pippa 鈥� nothing you can do to stop it I鈥檓 afraid鈥� learn to love it in its various guises!

Q - I have a conifer in my garden. about 30 feet high (9.1m). It is next to garage. I can see its roots are lifting up concrete path to garage. If I don't do anything, in future I suspect stem/roots will grow fatter, Hence lifting the garage floor as well.

If I get someone to cut about 10 feet (3m) top of this tree, will it's roots grow fatter?

Sally 鈥� You鈥檙e going to have to choose between the tree and the garage!聽 If you attack it the roots will attack back.

Pippa 鈥� Even the dwarf conifers really aren鈥檛 dwarf at all 鈥� I had one removed at at least 30ft.聽 I鈥檇 side with the garage and take the tree down.聽

Matthew 鈥� Hacking it back won鈥檛 slow the roots down and conifers (with the exception of Yew) don鈥檛 grow from the top if they鈥檝e been cut back.

Q 鈥� Each year I have to start off more cucumber plants than I need.聽 They reach about 10cm/4in high and then collapse and shrink to nothing in a very short time.聽 I sterilize my compost on the stove before applying it. I don鈥檛 have the same problem with my tomatoes.聽 Why is this happening?

Anton Rosenfeld from Garden Organic 鈥� I reckon it鈥檚 a fungal disease.聽 Cucumbers are particularly susceptible to diseases of the stem especially the stems are in contact with damp soil.聽 I鈥檇 be careful about not over watering.聽 Also, fungi can lurk in seed trays so make sure to wash them thoroughly.聽 Water with fresh tap water from clean water cans to avoid water-dwelling fungi.聽

Pippa 鈥� Avoid water butt water. Go for sterilized proprietary compost.聽 Don鈥檛 plant too deep 鈥� the stem needs to be above ground.

Bob F 鈥� Don鈥檛 sterilize compost for too long! Because above, say 150 degrees for 10 minutes, you can actually get more fertility.聽 Tomatoes might cope with this but cucumbers won鈥檛.聽

Q 鈥� Can I use leaf mould from underneath spruce trees to fill raised beds in the polytunnel?

Anton 鈥� Generally leaf mould is wonderful stuff but from underneath pine trees it鈥檚 going to be quite acidic and quite hard to break down.

Pippa 鈥� You can use them as a mulch against slugs and snails 鈥� very effective 鈥� particularly good around strawberry plants

Bob F 鈥� Best put it under other conifers

Q 鈥� My front door opens straight onto the street.聽 I recently put a pot of flowers outside and various other neighbours are doing the same so the road is getting to be a little more colourful.聽 Now I鈥檇 like to plant a climber up the front wall.聽 It鈥檇 have to be in a pot, the wall is brick, south-facing, getting full sun almost all day, it does get very hot and things dry out fast.聽 Suggestions please.

Matthew 鈥� I鈥檇 go for an annual rather than perennial climber.聽 Something like Morning Glory or an Eccremocarpus which has cigar flowers basically and grows very quickly.聽 Black-Eyed Susan too.

Anton 鈥� I鈥檇 go for something edible.聽 Mouse Melons look great and taste great.聽 Looks like an olive-sized rugby ball with a crocodile skin and it tastes like a lemon-flavoured cucumber.

Pippa 鈥� A Pineapple Broom.聽 You would need a support system but it has lovely silvery foliage, yellow flowers, and doesn鈥檛 mind being baked.聽 Make sure you use a really big pot so it doesn鈥檛 dry out so quickly.

Bob F 鈥� I鈥檇 put it a mix of red and white flowering runner beans

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