May 2022: Val Bourne on ‘Butterflies in Gardens’

CABAHS welcomed Val Bourne to speak at our May meeting, sharing her photographs, experience and knowledge of butterflies in the garden. She emphasised that she is not a butterfly expert (but she knows one!), she’s an organic gardener who has spent a lot of time observing butterflies, their habits and preferences – and, sadly, their decline in recent years.

Photograph of the FSC's Butterfly ID chart

As a starting point, Val recommended a book and a tool: ‘The Philips Guide to Butterflies’ and the Field Studies Council’s butterfly identification chart. Butterfly Conservation also provide a range of identification guides online. Photographs of a wide range of species – 24 different ones have been spotted in the Spring Cottage garden – showed us the beauty of even the smallest, brownest examples!

Val explained how useful even a small meadow area is for many species, how some species rely on quite a narrow range of plants for nectar, and how the timing of a butterfly lifecycle is intrinsically linked to the lifecycle of their food plants. She stated that climate change – causing plants to flower at different times – is demonstrably messing up this synchronisation, so as gardeners it’s important to grow a wide range of butterfly-friendly plants to try to mitigate that situation.

Some examples of butterfly-friendly plants, and the butterflies that particularly need or enjoy them:

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  • Buddleja davidii – known as the ‘butterfly bush’ for good reason! It can attract up to 22 different species
  • Origanum majorana aka marjoram – its nectar is particularly sugar-rich
  • Urtica dioica aka stinging nettle – this plant is especially good for five butterfly species (the Small Tortoiseshell, Comma, Red Admiral, Peacock and Painted Lady)
  • Scabious – this group of plants, including the field scabious (Knautia arvensis), have a long flowering season and are rich in nectar
  • Sweet pea – especially the perennial sweet pea (Lathyrus latifolius) for Brimstone butterflies
  • Cardamine pratensis aka cuckoo flower or lady’s smock – for Orange Tip butterflies (also garlic mustard, wallflowers, sweet rocket)
  • Ilex aquifolium (holly) – for Holly Blue butterflies (also Hedera – ivy – for later in their lifecycle)

Long grass is especially important for the ‘brown group’ of butterflies (which are not all brown!) because they lay their eggs on native grasses. Examples of these are Gatekeepers, Graylings, Small Heath and Marbled White butterflies. This is a group that tends to be smaller and less noticed, but it is worth paying attention as they are as beautiful as the showier, higher flying butterflies on closer inspection.

Val took a number of questions at the end of her interesting talk, and heard about plans for leaving some long grass in Charlton House Gardens and a suggestion from the floor to visit Ladywell Cemetery, which is actively managed with butterfly conservation in mind and occasionally holds butterfly identification walks through Big City Butterflies.

A full house for Val Bourne’s butterfly talk!

Ali


Val Bourne gardens at Spring Cottage in Cold Aston, Gloucestershire and is an award-winning garden writer, organic gardener and lecturer. Her writing appears regularly in the press, and her most recent book is ‘The Living Jigsaw’.

Spring Show 2022 Report

We held our first actual Spring Show on Monday 11th April in Charlton House Long Gallery, after two years of Online Shows. Everyone seemed pleased to be back but there was clearly a shortage of suitable material in some classes, with no entries in the Hellebore Class and only one in the Flowering Shrub Class. This seems to have been caused by recent weather conditions and their effect on flowering.

Vija and Pat judged the entries and because Vija’s was the only entry in Class 3, that class wasn’t judged! Vija announced the winners as:
Class 1 Daffodils/Narcissi – 3 stems: Maria B
Class 2 Tulips – 3 stems: Margaret M
Class 3 Flowering shrubs – 3 stems: (insufficient entries)
Class 4 Camellias, Rhododendrons, Azaleas or Magnolia – 1 stem of any: Maggie T
Class 5 Small vase of mixed Spring Flowers: Anna L
Class 6 Any pot-grown plant (indoor or outdoor): Kathy A
Class 7 A pot of Spring bulbs: Nicholas B
Class 8 Hellebores – 3 stems: (no entries)
Class 9 Tea cup floral display: Kay P

The Best in Show was selected by John King, a guest from Eltham & Avery Hill Gardens Society. He chose Sian T’s entry for the Tea Cup Floral display which she called “Teacup Fantasy”.

Vija reminded everyone of upcoming Events and Outings and encouraged everyone to check out our updated Website, Subscribe to receive an email whenever any new post is added and email CABAHS any feedback the website. Subscribing costs you nothing, keeps you up-to-date and you can Unsubscribe when you wish.

February 2022: Melanie Aspey on the Rothschild Legacy in Horticulture

The talk was given by Melanie Aspey, a CABAHS member who has been the Rothschild archivist for 28 years. Providing photographs and documentation from the Rothschild archives, she said the Rothschilds are best known for banking, their art collections, philanthropy and wine, but many of them have also had  a keen  interest in horticulture reaching back to Mayer Amschel Rothschild (1744-1812), the founder of the dynasty, who lived in the Frankfurt Jewish Ghetto.

After the defeat of Napoleon, thanks to their support for the allies, the Rothschild family was able to lobby for the retention of the right for the Jewish Community to buy real estate outside the ghetto. Mayer Amschel’s son, Amschel, considered that building a house would be too ostentatious, but a garden would better serve their needs. Instead he established a garden which he subsequently opened to visitors and for charitable purposes. He spent vast sums on plants, some of which (and Melanie showed one of the plant sale receipts from the archives) he imported from England. Later taken over by the Nazis and bombed by the allies, the garden fell into disrepair but parts have recently been renovated.

Continue reading February 2022: Melanie Aspey on the Rothschild Legacy in Horticulture

January 2022: Anne Barnard on Dahlias

Anne Barnard from Rose Cottage Plants nursery in Essex has many years experience of and is a specialist in growing dahlias, as well as exhibiting widely including at RHS shows. Dahlias, which originate in Mexico and Central America, come in a wide variety of colours from pastel to rich reds and mahogany.

Anne described how planting dahlias in summer beds can transform them and suggested how to choose and use them to best effect. Anne said they provide an outlet for personal creativity, style and artistic expression. She used her own garden, field displays in Holland and Chenies Manor as illustrations.

Dahlias had gone out of fashion, but in recent years there had been a revival of interest in them.  Their rich colours were particularly attractive and ‘jewel’ gardens had become common.  Many new and more popular and often exotic looking varieties had been developed. Many originate in Holland and she visited several important and influential growers. She said after bulbs, tulips and alliums have flowered by June/July,  gardens begin to look tired and dahlias wide variety and rich colours give life to the garden and make a good display right up to the first frosts.

Anne went on to describe a wide variety of dahlias:

Continue reading January 2022: Anne Barnard on Dahlias

October 2021: Dr Mark Spencer on ‘Murder Most Florid’

The guest speaker for October was Dr Mark Spencer who gave a fascinating glimpse into his experience of working as a forensic botanist. It became clear that forensic botanists are a rare find throughout the UK and the world.

He explained that from being brought up within a rural farming background in Warwickshire, he studied at the Royal Botanic Gardens, Kew. However he realised he did not want to pursue horticulture as a job and moved onto studying Botany culminating in a Doctorate looking at the evolution of fungi. While working at the Natural History Museum where he had become an expert on various aspects of botany, he was approached by a Police department asking whether he could help work out how long a body had been in a canal.

He has now worked alongside numerous police forces and an array of other experts such as soil scientists, experts in the study of pollen and forensic entomologists (study of insects) to assist in missing person searches, assessing how long human remains had been in-situ and linking suspects to crime scenes.

As a forensic botanist, Dr Mark Spencer looks for useful evidence using his knowledge of the rhythm, structure and behaviour of plants within their eco-systems. This can range from observation and interpretation of how vegetation is growing at a scene being investigated, to a microscopic identification of fragments of foliage found on clothing, to looking at the stomach contents and understanding the botany within a person’s digestive tract.

He explained how the roots of plants can help provide understanding of how long ago human activity occurred at the scene. Brambles (Rubus fruticosis) can be very useful tools for estimating how long bodies had been lying in woodlands or hedgerows through the knowledge of how they grow at different stages, when they send out side shoots and number of stems produced. I have a feeling that my walks through Oxleas Woods, which are full of brambles, will never be quite the same again!

Sharon


Dr Mark Spencer is an experienced and internationally respected botanist. His expertise covers many disciplines including forensic botany, the plants of North-west Europe, invasive species and the history of botanical science. He works globally as a writer, public speaker and television presenter and has appeared on BBC Radio 4’s The Infinite Monkey Cage. He is also Hon. Botany Curator of the Linnean Society of London. Dr Spencer’s website gives a detailed description of his range of expertise.

Autumn Flower, Fruit and Vegetable Display 2021

This was held on Monday 20 September in the Long Gallery of Charlton House. As one of many new members of the Society since meetings were forced to stop by COVID-19, it was my first indoor meeting!

It was a very impressive event with a total of 66 entries and I didn’t envy our guest judge, Joe Woodcock, his task. But Joe made it clear how impressed he was with all the entries, providing an encouraging commentary on the horticultural skills demonstrated, and explained why he selected the winning entry in each class.

The classes and winners were as follows:

1. Vase with single stem of any flowering plant – Viv P

2. Bowl of mixed flowers – Margaret T

3. Five Fuchsia blooms – Ruth Y

4. Ornamental pot plant – Pat K

5. A display of fruit and vegetables – Mandy & Brownie

6. A display of herbs – Ruth Y

7. Floral arrangement in a teacup – Anna L

8a. Potato Competition – Pam D

8b. Sunflower head competition – Annie H

Joe selected as Best in Show Margaret T’s wonderful display of varieties of dahlia in Class 2. Class 7 the Floral Arrangement was selected by popular vote (using buttons) and the Potato Competition was weighed by the trusty scales of Hugh P.

Joe was kind enough to answer a few gardening questions at the end of proceedings, and tea, coffee and biscuits were provided to round off the evening.

We counted 56 attendees. Everyone seemed to enjoy the event and be grateful to be able to meet up in person again. Long may that continue!

Lynda

August 2021: Amateur Gardeners Question Time “GQT”

Our amateur “GQT” was attended by over 50 members and OPG volunteers and was held outside, in the Peace Garden behind Charlton House.  Our president, Sir Nicolas Bevan, introduced the panel experts – guest panellist Joe Woodcock, plus Vija Vilcins and Pat Kane. It was an exceptional meeting.  As Sir Nicolas said, this was the first time members have met face-to-face since the beginning of the pandemic. To celebrate this it was also a social event with wine and nibbles provided – and appreciated!


Questions and Answers

Q1
Stella B: I would be grateful for some suggestions for a small or medium sized tree for my back garden. It’s a ’coming along’ garden begun a couple of years ago. There are now 3 apple trees (2 half standards and one espalier), so not another fruit tree. I really need it for some screening (it’s a terrace house) so maybe 12-15ft full grown? Not too wide a spread.

Q1 ANSWERS:

a) Joe: 

i) Although Stella was not keen on fruit trees the crab apple would be a good tree. e.g. Malus ‘Red Sentinel’ with its wonderful golden leaves.

ii) Japanese maples (Acers) e.g. Senkaki with  its yellow leaves in summer and its beautiful golden tints in autumn when its leaves become tinged with pink. Or Acer palmatum ‘Garnet’, a low growing acer.

iii) Rowans such us Sorbus acuparia and Sorbus ‘Joseph Rock’,  yellow flowers with superb autumn colour.

iv) The Handkerchief Tree (Davidia involucrata).  But maybe too large if the garden is small.

v) The Fox Glove Tree (Paulownia tomentosa).  Because it grows into a large tree, buy it young and coppice it. It will then grow into a low growing shrub with very large leaves.

b) Pat:

i) The Paper Bark maple ( Acer griseum) and the Snake Bark Maple(Acer capillipes).

ii) Amelanchier lamarkii.

iii) Prunus ‘Snow Showers’ which hangs down.

c) Viya:

i) Amelanchier.

ii) Cornus canadensis.

iii) Cercis canadensis ‘Forest Pansy’ with burgundy leaf.

Q2
Chris B: I was given a Geoff Hamilton rose at the end of May and it flowered beautifully, but there have been very few flowers since then. It is supposed to be a repeat flowerer. Is there anything I can do to encourage more roses?

Q2 ANSWERS:

a) Joe:
It’s a modern shrub rose. If bought in a pot it needs time to establish. The roots need tweaking out before planting and it needs time to acclimatise  to the soil and develop the  energy  for flowering and will very likely  flower better next year  when it has had time to acclimatise. In spring give it a mulch  and feed it with Tomorite.

b) Viya:
Referring to roses in pots she said she had  kept an Emma Hamilton rose in a pot and it needed a regular feed  because the soil gradually lost its nutrients.

Q3
Pat K: I’ve got scale insects on the trunk of my Viburnum bodnantense Dawn. It’s planted in a pot as no room in the garden. The best way to get rid of it without any chemicals, please?

Q3 ANSWERS:

a) Joe:
Using cotton buds with methylated spirit, and squish them! Systemic fertilisers have been mostly withdrawn nowadays. Ants may form nearby which harvest them, but they are harmless.

b) Viya:
She said she has used a fingernail scrub. A labour of love. But they didn’t come back.

Q4
Carolyn H: My clematis (several varieties) are covered in black fly this year. The flowers are also being eaten. Are these two problems related? Is it a particular problem this year? How can I prevent it happening in future. Three questions actually!

Q4 ANSWERS:

a) Joe:
He said that his clematis were the best they have ever been this year! But the black fly problem may be due to the weather conditions this year. Use a hosepipe to wash them off or squash them with your fingers. If you use chemicals use a fatty acid one not a systemic . They may have been eaten by slugs and snails. Well known ways of getting rid of these include using egg shells, beer traps and   wool. Also there is the book ‘50 ways to Kill a Slug’ by Sarah Ford.

b) Pat:
Go out at night with a torch and pick them off.

Q5
Kathy A: Do you have any suggestions or rules for how to space perennial plants out in a herbaceous border? I always start off ok but by about now everything looks squashed and lots of fighting for space going on. I was always told not to leave bare soil between plants as then you get weeds, but I don’t seem to be able to find that happy medium.

Q5 ANSWER:

a) Joe: I do the same. I suggest you cut back the thuggish plants in summer and make space for others. If it is a new border plant in odd numbers e.g. 3, 5, 7 etc. Fergus Garrett at Great Dixter has produced a video showing how to space out plants.

Q6
Melanie A:  I would appreciate some suggestions for plants to go in a shared space. This is the scenario: our houses are fortunate to share a fairly large open space for which the householders are jointly responsible. We keep maintenance costs to the minimum by doing much of the work ourselves. Some of the trees planted many years ago by some householders help shield us from the horrors beyond, but they cast a lot of shadows. It would be great to have some thoughts  on how to put some items of interest in this space, something that can’t be mistaken for lawn by enthusiastic mowers.

Q6 ANSWERS:

a) Joe:
In shaded areas plant Mahonia, Camellia, Elaeagnus and in damp shade ferns e.g Dryopteris wallichiana and Dryopteris filix-mas. Also plant in groups: Epimedium , Pachysandra terminalis, Pulmonaria  ‘Sisinghurst White’. Foxgloves (Digitalis) and Japanese anemones(e.g.Honore Joubert) to show up in the shade. Spring bulbs like Tulip Red Riding Hood and Tete-a-tete.

b) Viya:
Miscanthus which initially only needs minimal watering just to get it going. Also Nandina domestica and Hydrangea ‘Vanilla Phrase’.

Q7
Angela B: Have you any suggestions for getting rid of pond duck weed?

Q7 ANSWER:

a) Joe: You can never get rid of duck weed. But use waders and a metal rake to clear it. Do leave it on the side for a day so that any organisms in it that need to live  in the pond can return to it. Also, if new, place your pond near a bit of shade. Put in oxygenators and pond plants that will help maintain a balance such as irises and marsh marigolds(Caltha palustris). Try to maintain at least one third cover with lilies and marginals. Also a fountain would be useful.

Q8
Anne R:  I have a Sorbus (Rowan)  which I think is Sorbus ulleungenis ‘Olympic Flame’.  It’s about 8 years old and still quite small and every year some of its growth dies back. It’s in a north-by-northwest  garden, so it gets some sun, on heavy clay but well drained. Am I doing something wrong or is it the wrong tree for the space. I know I’m not the only person with a die-back problem I saw a Sorbus in Greenwich Park recently with the same problem.

Q8 ANSWER:

Joe: The rooting of Sorbus is vulnerable to extremes of environmental conditions. It doesn’t like heavy wet soil in winter and cracked soil in summer. Take a garden fork and lift and reduce compaction around the roots. Waggle the fork in the roots (“terra vent”). Mulch in winter. Monitor the tree and cut out dead wood.

Angela

July 2021: Dusty Gedge on roof gardens

Dusty Gedge was welcomed to the meeting. Dusty is a professional photographer and green structure and nature conservationist.  He is President of the European Federation of Green Roof and Wall Associations.  He said he was pleased to talk to CABAHS as he was local, Lewisham and Blackheath based, and had done a lot of work in the area. He said he is not a gardener but is involved in plants and soil.

Dusty made the point that green roofs and roof gardens have a local history, firstly showing a photograph of  the 1997-built sustainable green roof  on the now demolished Sainsburys on the Peninsular, followed by  one  of the 2019-built IKEA roof garden. In fact, Greenwich and Lewisham have the second and third most green roofs in London. Nowadays in England, including the City of London, it is planning policy that all tall buildings should have green roofs.

Dusty said that nowadays green roofs are becoming numerous. He showed photographs of a wide variety of them from Europe and the UK. From roofs in parts of Europe where traditionally turf and sedums were used to  modern schemes, including nearer to home  such as the roof garden at the National Theatre.  He said there were 4 types of green roof (intensive, semi-intensive, biodiverse and extensive) and discussed the environment, conditions and maintenance needed for the various types to flourish.

Green roofs and roof gardens are taking soil and plants into the cities.  He referred to ‘plumbing with plants’ using soil and vegetation as they store water, helping to ameliorate floods. They also help in heatwaves and the green space they provide fosters health, wellbeing and social cohesion.

He discussed two projects, the Museum of Home and Design which balances diversity with formal garden design using mediterranean and native plants and then IKEA with its four different sections. He said he would be happy next year to take CABAHS members on a tour of IKEA’s roof garden.

Afterwards, Dusty took questions and was asked by a member (who is also a surveyor) about infrastructure needed to support the roof and prevent leaks. He agreed that is an issue and said there were many structural strategies existing to prevent this happening.  Another asked what would be the effect of wind on tall buildings. Dusty pointed out that the roofs of tall buildings were generally less windy than at ground level due to the funnel effect. He also reassured members that he collects local wildflower seeds in a sustainable way.

Angela


Dusty Gedge is a green infrastructure professional, public speaker, photographer, nature conservationist and social media influencer. He is President of the European Federation of Green Roof and Wall Associations and a recognised international speaker on green roofs, green infrastructure and biodiversity.

Dusty gave several links to useful websites and a podcast, below. He said members are welcome to contact him for advice.

https://www.theguardian.com/lifeandstyle/audio/2015/nov/14/podcast-green-roof-sow-grow-repeat-gardening

http://www.growingontheedge.net/viewtopic.php?p=103296

https://greenrooftraining.com/shed-green-roof-wa/