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Tresco Abbey Garden: Correspondence Edition

Eric Robson hosts a correspondence edition of the programme from Tresco Abbey Garden on the Isles of Scilly. Pippa Greenwood, James Wong and Bob Flowerdew answer the questions.

Eric Robson hosts a correspondence edition of the programme from Tresco Abbey Garden on the Isles of Scilly. Pippa Greenwood, James Wong and Bob Flowerdew answer the questions from the postbag, along with Mike Nelhams, Curator of the gardens at Tresco Abbey.

Produced by Dan Cocker
Assistant Producer: Laurence Bassett

A Somethin' Else production for BBC Radio 4.

Available now

43 minutes

Fact Sheet

Q – I have brown marmorated stink bugs (BMSB) on my allotment, how can I control them using organic methods?


Pippa – They don’t do significant damage and I wouldn’t try and control them.


Bob – They may be helping to eat other pests


Q – My South African Geranium (Pelargonium sidoides) stays small and the main stalk is bare, what can I do to get it to grow more leaves?


Bob – I would cut it back and get some side shoots from it and put it in a larger pot in more sunshine.


Pippa – I would consider putting it outside in the summer in a sheltered spot.


James – The window could be filtering out the light so put it outdoors and cut off the top.


Q – I have honey suckle growing in my privet hedge, how should I treat it as part of the hedge?


Bob – I would pull the long shoots back into the hedge, leaving the tops out to encourage growth.


James/Pippa – I would choose to keep one or the other as they don’t mix very well together.


Q – Please could you advise on collecting seeds from plants such as Foxgloves, Aquilegia etc. Is it possible to cut the plants down soon after flowering and collect the seeds when the plant is dried or is it best to allow the seeds to ripen while the plant is in situ?


Mike – I prefer to leave the seeds in the plant and wait until they’re ready to be collected.


Pippa – You can cover the plant in a brown paper bag rather than a plastic bag to collect the seeds.


Bob – Try and select the best seed rather than taking all of them. Take them from the best grown heads because you want something that’s healthy.


James – You need to wait until the plant is fully ‘ripe’ for that seed to be viable, if you cut them off too early they will not continue to ripen away from the parent plant.


Q – I have two Jasmine plants to grow up the side of my balcony on a trellis, how can I train them into a bush?


James – If other people are looking to do the same I would choose a Cape Jasmine (Trachelospermum jasminoides) if you want dense flower growth in a small space. For the Jasmine already planted I would prune it to encourage lateral, thicker growth. Depending on the type of species such as Jasminum officinale, you could see very few flowers on very large plants. If you have Jasminum polyanthum then it will produce a denser flush of flowers earlier in the year but neither will produce a large enough quantity of flowers in the balcony space.


Mike – Instead of Jasmine we grow Australian Kennedias, they love a hot, dry wall and vary in colour: black, red, orange.


Bob – If you want something bushy you could try Natal Plum (Carissa macrocarpa), it produces a lot of large flowers with a similar Jasmine smell.


Q – We have a very large kiwi tree and a huge crop of fruit, how do you suggest we control it?


Bob – Try not to pick the fruits until the leaves are formed. I would peel the fruit and turn it into sorbet and freeze it.


James – I am excited about a Siberian species of kiwi called Actinidia argute (not Actinidia deliciosa which are the recognizable brown fuzzy ones), they are small and you can bite straight into them. They are significantly sweeter, contain less acid and are hardy down to minus 25 degrees Celsius (77 Fahrenheit).


Q – We have a lot of bumble bees attracted to our Cherry Tree, why is that?


James – It might be a form of Ethno Zoopharmacognosy, where animals understand certain medicinal properties about plants and actively seek them out for various uses.


Q – Our apple tree has white, fluffy, fungal growth on its branches. The branches are stumpy and the apples are falling off too early, leaves are withering and dying. Can you help?


Pippa – It’s not actually a fungus it’s a pest called Wooly Aphid (Eriosomatinae). If you pull apart some of the white fluff you will see the aphids. You can try and clean it with a nail brush and some soapy water.


Bob – You can brush them off with a stiff brush or use a soft soap with a soft brush.



Q – Last year I purchased three 'tropical' style plants - Melianthus Major, Tetrapanax papyrifer ‘Rex’ and a 1.2m (4ft) high Paulownia tree. They are planted in a north facing border which does get a decent amount of sun as its on the east/west axis with nothing shading it out when the sun is high.  The Paulownia has subsequently just stopped in its tracks, with no new growth evident in the warmer weather. Should I cut back to the main stem to promote a restart?


Mike – We don’t grow Paulownia because its leaves are too delicate for the possible wind damage. It is most likely to be too cold for Tetrapanax.


Bob – I cut back my Paulownia tree leaves every year so that I get those strong shoots. I think it is likely that the roots were not properly teased out before planting from the pot. It may find its roots in time.


James – It might be water stress.


Q – My son has a Handkerchief tree (Davidia involucrata) in his garden by the sea and it has been happy there for seven years. This year the foliage is not looking as healthy, the leaf seems to have a brown tinge to the edges. How can he improve the condition of the tree?


Pippa – The early part of this year was dry and that could have caused damage. It could need more water and possibly mulch too. The salt winds could also have damaged it.


Q – We have a mountain ash which has developed a gap in its bark. The product I used to fill it has hardened and cracked. What is a better method to fill the gap?


Pippa – I would leave it alone, it will naturally form compartments around a wound, whereby the damaged parts will be allowed to die off and form a barrier against invading pathogens.


Q – Should I re-pot my acorn tree from its pot after 30 years?


Pippa – Yes definitely. It could be difficult but make sure the roots are teased properly. Maybe move it into a larger pot first to help the roots.


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