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Westonbirt Arboretum

Peter Gibbs hosts a tree special from Westonbirt Arboretum. Chris Beardshaw, Anne Swithinbank and Bob Flowerdew answer the horticultural queries.

Peter Gibbs hosts a tree special from Westonbirt Arboretum.

Chris Beardshaw, Anne Swithinbank and Bob Flowerdew answer the questions.

This week the panellists delve into the postbag to catch up on some queries about trees from GQT listeners in the UK and abroad.

Also, Chris Beardshaw meets with staff at Westonbirt to discuss the 2050 Glade project which trials plants from different provenances to see how they perform in a changing climate.

A Somethin' Else production for Â鶹ԼÅÄ Radio 4.

Available now

43 minutes

Last on

Sun 22 Nov 2015 14:00

Questions and Answers

Q - We have a holly tree approximately 5metres (16.5ft) high, however we never get to enjoy the berries. ÌýThey start to turn red at the end of August but by the end of September squirrels have removed the lot. ÌýMy main concern is the damage to the tree as they bite off lengths from a few centimetres to half a metre, just to remove one or two berries and discard the rest. Is there any thing I can do to stop this damage? I am considering a ultrasonic movement detector to repel the squirrels but don't know if they are effective. ÌýI am very happy for the birds to take the berries after Christmas which is what used to happen until the squirrels moved in.

Anne – I have hollies and squirrels and I find the squirrels don’t eat the berries.Ìý Maybe it’s because I have hazels nearby – perhaps try planting hazels to divert them?

Bob – Ultrasonics are ok but squirrels are persistent and probably won’t be deterred long term.Ìý It could also be Mistle Thrushes taking the berries.

Chris – You could try an inverted collar around the tree trunk – protruding about 50-60cm (20-24inches) – almost like a dog’s veterinary collar, to stop the squirrels getting any purchase.Ìý Will only work on an isolated tree.

Ìý

Q - Potatoes accidentally left in the ground often grow the following year. It's possible to buy early seed potatoes in the autumn for a protected crop for Christmas. Can I just plant them un-chitted (in late autumn) for an earliest possible crop in spring?

In both cases, and recommendations for varieties?

My allotment is on a warm, south-facing slope, protected by nearby trees, well-drained, well-supplied with farmyard muck and "fertilised" by the grave-yard at the top of the hill.

Bob – Yes – I plant half my potato crop in the autumn.Ìý It’s a lighter crop because you don’t chit them and they don’t go with the same speed as the spring.Ìý I would put them in a bit deeper to protect from the cold.

Ìý

Q - In 2011 - probably like many people - I bought a 'mini orchard' of one Braeburn Apple; one Victoria plum; one Cherry and one Conference pear. The first year I had one apple, which I removed. No fruit from any tree the following years. This year I had a good crop from the cherry and pear but no apples or plums. How can I encourage the Apple and the Plum to fruit? They are approximately 3mtrs (10ft) tall and planted in south east facing plot with plenty of home-produced compost mulch each year.

I live in Rotherham, South Yorkshire. Should I give up on them?

Penny Jones (Westonbirt expert) – I think it’s good to mulch, however, fruit trees need quite a lot of potassium to produce good fruit. ÌýAdd this in late January.Ìý Sometimes apples need a cross-pollinator – a Crab Apple on a dwarf rootstock would do if you don’t want a full apple tree – I like Malus ‘Evereste’

Bob – re: the lack of flowering – it could be Bullfinches.Ìý They will strip the buds from fruit trees, especially plums.

Chris – These are young trees – the first few years are all about setting the roots and pruning well and then the fruits will follow.

Ìý

Q - I want to buy a bare-root peach tree to grow in a pot so that I can avoid leaf-curl by putting it in my 12’ x 8’ (3.6m x 2.5m) greenhouse in early spring. I don't mind pruning but I don't want to wait years for it to fruit. What would you recommend?

I’m happy to prune/pollinate and place it out in my sheltered South facing veg plot.Ìý However in order not to have to wait even longer for my first peach, what do I need to do in order to get it to fruit ASAP!

Penny – Keeping it in the greenhouse in early spring will prevent the onset of peach leaf curl but definitely move it out for the summer months

Anne – I use dwarf peach trees in pots to make them more manageable.Ìý I’d get an apricot too

Bob – Peento and Bonanza are good varieties.Ìý For England, the most reliable, are Rochester and Peregrine peaches.Ìý Put them in tubs, bring them in on January 1st, and put them back out after the first fruits in June.Ìý

Ìý

Q - We have plenty of earthworms in our plastic compost bins. ÌýThe bins have an open bottom and are regularly "fed" with vegetable peelings, garden waste, plus torn up paper bags, hoover dust etc. ÌýThey stand in a spot that gets the sun for part of the day and often become quite warm.
My question is this: every now and again the worms move up to the top of the bin, often gathering in the lid in clumps. ÌýIn order not to crush them when replacing the lid, my husband and I have the choice of either pushing the worms back into the bin (from which they appear to be trying to escape) or putting them in or on the soil. ÌýWhen we try the latter the worms do not attempt to bury themselves. ÌýI wonder if they will not thrive outside the warmth of the bin.
So which should we do, keep them in the bin or add them to the soil?

Bob – These are different worms (called Brandling).Ìý In the soil they will only go for topsoil, as they don’t like digging.Ìý Keep them in the bin.

Anne – You need to put in some semi-composted in material for them to enjoy immediately… they are climbing to the top because they can’t tuck into your fresh peelings straight away.

Ìý

Q - A large French bay tree has grown next to the stone wall of my house and its roots have grown into the wall creating a large damp patch on the lime plaster inside. What is the safest way to remove the tree completely?

Andy (Westonbirt expert) – A qualified tree surgeon should be able to help quite easily and then I’d recommend getting a builder in to advise on the remaining wall.Ìý And poison the remaining stem to avoid those suckers coming back.

Anne – It might not be the tree – get the builder in first to see what is causing the damp for sure.

Ìý

Q - I moved into my current property around five years ago. The front garden has two very old oak treesÌýand about 10 conifers and shrubs.ÌýAÌýtree had been felled shortly beforeÌýI moved in. I had noticed a lot of fungi around this but thought nothing of it. Over the course of the past five years I have noticedÌýmore and more fungi around the garden and more things dying.ÌýI recently had a survey carried out by a tree surgeon and he has advised me that it is actually honey fungus and that it has also attacked the oak trees and they will be dead within seven years.

I heard on one of your earlier programmes that there is very little I can do to stop it. I have lost 50% of the conifers over the past two years.

What I find daunting is the fact that once it has done its worst, I cannot plant for two years! So if I built raised beds and imported new topsoil, would the planting survive?

Andy – Remove any of the old stumps and get rid of the material completely to stop it spreading.Ìý Raised beds could be a solution – as long as they are completely sealed off, possibly with polythene.

Ìý

Q - I live on the fourth story of a block of flats, in Lahti, Finland. A semi sheltered balcony but open to the elements. In summer it gets about six hours of good sun. Unfortunately in winter that starts about October we start to get sub-zero temperatures until April possibly May if a bad night. I want grow plants in containers and just want recommendations for plants for the summer months. I would like a bit of colour, green is acceptable. Maybe a few herbs for the kitchen would be nice.
Bob Flowerdew will say get started early, hardening of in a cold frame and plant out on February. In Finland, cold is possibly -10 to -20 at this time.

Bob – Strawberries would do as they are dormant in winter and get going quickly.Ìý Some of the annual herbs such as the Chervil, Parsley and Basil, too.

Anne – I might suggest a Birch in a pot and, herb-wise, Marjoram and Lemon Balm.

Chris – I agree with Anne with the Birch – though I’d go for Betula nana, one of the Tundra plants.Ìý Also, the Korean Pine.Ìý And, for ground covering I’d go for Microbiota decussata.Ìý

Ìý

Q - How do I grow a ginger plant from a piece of root obtained from the supermarket? ÌýWhen I've either soaked a piece developing shoots or planted it under compost it rots.

I have tried on several occasions to encourage sprouting ginger roots to develop further into plants but have failed). I have put sprouting roots into waterÌýand also tried potting them using compost. ÌýBut they just seem to rot and don't develop into plants. ÌýWhat do I need to do?Ìý

Anne – It’s being kept too wet.Ìý I’d be tempted to use two parts compost to one part grit to aid airflow and drainage.Ìý

Chris – Bottom heat is the most important thing.

Bob – Supermarkets take the buds off if they can – so find one with buds on for best results, then bottom heat, good drainage, and dappled light.

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