pests – Charlton and Blackheath Amateur Horticultural Society

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

Here we go gathering slugs in May…

On Sunday I picked 22 slugs off my small hostas (just to reassure readers, I don’t do this regularly – I do have other things to do!). With the advent of damper weather they are really starting to show themselves. For those who love growing hostas, slugs and snails are probably the biggest pests and even the giants like Sum and Substance and Big Daddy are not always immune to their predations. Growing in a coarse medium, or using environmentally friendly slug pellets, doesn’t necessarily solve the problem because slugs are smarter than you think. If necessary they will abseil down a neighbouring plant to get at the leaves of your hosta, so anything at ground level will not always stop them.

Emerging Hosta 'Patriot', with Hosta 'Undulata'

Preparatory products have been, rightly, removed from the market as they have proved toxic. A garlic wash has long been recommended as an alternative and I have used this myself in the past.

When I recently bought some new hostas (those of you who know my garden might wonder why I need any more, but I justified the purchase on the basis that one was a replacement for Dancing Mouse and the other was a gift) the recipe for a garlic wash was included with the plants, which I thought I would share with you. Please see below.

Vija

Musing on poisonous practices

In his book The Flower Yard, Arthur Parkinson writes lovingly about his grandmother Min and her gardening practices, typical, he writes, of an older generation of gardeners. He describes the kinds of plots tended by Min and her neighbours and how ‘there was no acceptance of insect life, as proved by the cupboard of death in the garage, its shelves packed with poison, weed killers and bug spray’[1].

My Mother’s death bequeathed to me not only her gardening tools, but a similar shelf’s worth of gardening aids. I have very vivid memories of the shed she and my Father had in their garden, the tools neatly lined up and clean, sweet jars ready for pickled vegetables, saved seed in envelopes and plant labels ready to be re-used. But alongside all this were also the toxins.

And it is not only a younger generation of gardeners who believe in far more environmentally friendly gardening practices. In a recent online talk given by Fergus Garrett, he argued that ‘gardening and ecology have to come closer together’ and devoted one whole lecture to how gardening at Great Dixter has become much more sustainable in recent years and delighting in the huge quantity of species that the gardens are home to.

Driving somewhere in the 1970s meant cleaning the windscreen and headlights of bugs on arrival home. That no longer happens and is a sure indication of how much insect life has been destroyed in a very short space of time.

Vija

[1] Parkinson, A. The Flower Yard (2021) Kyle Books p.119.

Now is the quince season…

With apologies to Rod Liddle, writing in The Spectator!

I am sad that my Quince tree (the produce of which gave me the CABAHS “Best in Show” cup once upon a time!) has not managed to bring a single fruit to maturity this year. Squirrels and the dreaded brown rot have taken all.

Quinces were first grown in England by Edward I, the ‘Hammer of the Scots’, a man who would have made short work of Nicola Sturgeon. The fruit resembles a degenerate pear — a pear which has made bad choices in its life. Downy and squat. The tree from which it emerges is a delight, especially in early May when fecund with blossom, which is the time that famous perfume begins to emanate. That perfume stays with you — in the fruit bowl, when you are peeling it and, most of all, while it is being cooked.

Like all good food, the quince requires work, time and an appetite for deferred gratification. It is a beast to prepare. Peel and core a quince and you will find a swede can be sliced through like butter in comparison. The flesh of the quince is fibrously obstinate and the core intractable; be careful with that knife. When you have finished peeling and quartering, set the seeds aside in case someone you really don’t like comes over. They are rich in cyanide. Toast them and say to your adversary they are pumpkin seeds..

Anyway, cook those quarters gently. Either poach in a couple of inches of sugared water, a dash of honey and perhaps a strand of thyme in a saucepan on the stove top, or in a bath of the same in the oven. The recipe instructions vary as to how long you should do this — some suggest 40 minutes. Rubbish. You need at least two hours on a low heat. Only then will the quince reveal its magic — the gradual metamorphosis from a wan, pale yellow to a rich crimson, the anthocyanins doing their work. Add another hour or so if you’re making quince cheese from the pulp and then another six to rest, before straining and cooking again with added sugar. It will set just fine due to its natural load of pectin.

I prefer the quartered fruit to still have a little bite; five or six segments and the reserved cooking juice will transform your apple crumble with a gentle tartness. You can purée the red fruit into an accompaniment for duck, or simply serve as they are, with their gloriously red and sticky cooking juice, topped with cream. Either way, hurry: the quince season is nearly at an end.

Kathy

“Opportunities for change” in the garden

A recent article by Nigel Slater vividly describes the various incarnations his garden has gone through in the past twenty years. The first iteration was designed by Monty Don over lunch and on the back of an envelope. The second, many years later, by Dan Pearson. Not all of us are so lucky to have such well-connected friends! But each change was inspired by the need to deal with a problem, whether it was a large family of boisterous foxes or the depredations of the box moth. What Slater points to is that gardens change (obviously) and that sometimes we can be forced into making changes which are an improvement on what we had already. In the business world ‘threats’ are re-purposed into ‘opportunities for change’. I don’t think this is always easy and I have been heartbroken to lose what I regard as old friends, but spaces and areas can be opened up in the garden which give opportunities to be more creative and to introduce something which you might not have tried before.

Many years ago, on one of my visits to gardens in France, I visited Le Jardin D’Agapanthe. I have never seen a garden quite like this anywhere else in the world. It was created by a landscape architect, Alexandre Thomas and includes no lawns, borders or views – the kinds of things you would normally associate with a garden, just winding paths of sand through lavish planting. It is at once romantic and exotic. There is an interesting inclusion of small stands or tables to raise plants above ground level and add interest. For anyone who loves pots, this place is inspirational.

When I have lost something in my garden I trawl back through photographs of places I have visited and loved to find new ideas and ways of using plants and spaces. Le Jardin D’Agapanthe is one that I often return to.

Have you lost a favourite plant recently? What “opportunity” did it open up? Let us know, write to cabahshortisoc@gmail.com

Vija

Tulip time in Elizabeth C’s garden

Elizabeth says “Last Autumn I had a beautiful collection of Sara Raven tulip bulbs for my birthday, which were carefully arranged in colour co-ordinated flow with wallflowers interspersed. Feeling generous to myself, similar colour groupings were arranged around my garden and I eagerly awaited this Spring.

Bulbs started to appear prolifically and my excitement rose; each day my first task was to check their progress with all the promise that entailed. Until – one morning, disastrous views unfolded – all the fully developed buds had been bitten off by The Squirrel! Only immature ones remain.

Apart from purchasing a shotgun on eBay, does anyone have any helpful advice to avoid repetition?”

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Such a sad story! Please email your suggestions to cabahsh ortisoc@gmail.com and let us know if you have had a similar problem? I have personally had plenty of problems with squirrels and bulbs, but once the bulbs start growing, my local squirrels (thankfully) lose interest. Christine has had success with putting curry powder in the soil, and Jenny puts prickly holly twigs around her pots, but this is really for the bulb stage. Other ideas needed!

Hooked on hostas

At the last count, I had 32 hostas and most of these are in pots. Admittedly, some of these are miniatures, but nevertheless this means that in March a lot of checking and potting on needs to take place. My basic collection has increased over the years because people have given me hostas which they have bought and not had much luck with and then passed on to me. I am always grateful!

HostaSumandSubstance — Sum and Substance

I check all pots to see whether root growth is coming through the bottom of the pot; where small enough I tip the plant out and check to see whether it is root-bound or the compost is looking a bit stale. However, Sum and Substance and Big Daddy are each about 4 feet tall and Big Daddy is in such a large pot it really needs two strong men to sort him out! Empress Wu is catching up with these guys in terms of size. I then use John Innes number 3 to pot up again. I try and leave a fair bit of space at the top of each pot to allow for the addition of a protective mulch. I make this with a mixture of farmyard manure and home made compost, which I keep as rough as possible with eggshells – this does a good job of discouraging slugs and snails while the plants are young and gives them a good head start. The coarser leaved hostas then tend to manage quite well thereafter. This year I have added a granular feed which should last 6 months. Many years ago I read somewhere that feeding hostas produces weaker growth, more susceptible to attack and I have never fed mine apart from the spring dose of compost, manure and sometimes bonemeal.

In my experience, the general gardening advice that the coarser the leaf the less likely a hosta is to be eaten by slugs and snails is true. Particularly resilient is Frances Williams and I can’t recommend this one enough. I also find Krossa Regal and Patriot very good. It’s also useful to think about where you are growing hostas. If they are crowded together in a border with lots of other plants, slugs and snails will still get to them no matter how many slug pellets you use. Snails can abseil down the leaf or stem of another plant to reach a hosta. As always in the garden, a consideration of the growing environment means there is less need to introduce artificial measures to control the pests.

Vija

In praise of… earwigs!

I have not been an earwig lover for all of my life. As a child, I remember my father making a nightly check on his prize dahlias and coming back into the kitchen with earwigs crawling out of the turn ups of his trousers. My mother’s predictable reaction meant that I thought earwigs were definitely not insects one was meant to love. Now years later, in my own garden, I can see the results that a small earwig population have on my own favourite Dahlias, Verrone’s Obsidian, and it’s extremely annoying. But this Christmas my husband gave me a book – “The Garden Jungle” by Dave Goulson and it has rather opened my eyes to the trials and tribulations of this little insect.

Goulson points out that earwigs are easily eradicated by sprays, and because they don’t fly and only produce one generation a year, they don’t re-colonise very quickly once they have gone. I haven’t used pesticide sprays for some years, with the exception of a drench for vine weevil in my containers, so I know I do have earwigs in the garden, although not in the numbers I remember as a child.

Earwigs are overwhelmingly beneficial insects, they feed voraciously on aphids, as well as munching on the occasional petal. In orchards where earwigs have been sprayed out of existence, trees are infested with three times as many woolly aphids as those with a good earwig population. It is generally the case that beneficial predators of a crop pest breed more slowly than the pests they feed on. Aphids, in particular, breed spectacularly fast, giving birth to live young which themselves have developing offspring inside them when they are born. In contrast, Mrs Earwig produces maybe 50 offspring a year, laying creamy eggs in a burrow in the ground towards the end of winter. She tenderly cares for the eggs, guarding, cleaning and turning them and looks after the young brood (nymphs) until they moult and gradually become independent. Then she turns them out of the burrow and they must look after themselves, foraging at night and hiding in the day in any crevice (or dahlia) they can find. They must do this all Summer and Autumn dodging predators while they grow, until winter comes and they find a mate and it all starts again.

The fierce looking pincers are actually quite feeble and incapable of doing harm to a human, they are used by the earwig in defence against predators such as ground beetles, and also in mating. The “wig” part of their name comes from an old word for “wiggle” and they definitely never burrow into ears!

We should certainly see earwigs as our friends in the garden, just as we now do ladybirds and lacewings. I have decided that a nibbled petal here and there is a small price to pay for all the good they do.

Kathy

Speaking of foxes: Tales of woe from a frustrated gardener

Foxes are the bane of my life. I first became a keen gardener twenty five years ago when I moved into my small three story terraced house close to Ministry of Defence land, a wooded conservation area, and was confronted with a back garden that was bare. Keen on wildlife, I decided to try and create a wild life garden, including digging a pond to encourage the breeding of frogs which over the years has matured successfully. However I had not bargained with the attraction this would have for the local foxes who much to my chagrin have come to see my garden as their play area and my pond a drinking place They have spent their time wrecking it, most days trampling down and pulling up the plants and bulbs, burrowing deep holes, messing up the paths and pooing everywhere. For example, enthused by the recent CABAHS talk on tulips, I bought a range of tulips which I planted in very large pots and colour schemed. As suggested by the speaker I planted violas on the top of them. The next morning I discovered the foxes had ripped them all up, muddled up the bulbs, totally messed up the different colours and ruined my design irreparably.

Foxes have three times got through my cat flap into my basement kitchen area. The stench they left was awful and on one occasion took two days scrubbing to get rid of. During the fox mange epidemic I even found a bald cub lying near death in my basement. As someone who would not harm an animal I contacted the South Essex Wild life and Fox Sanctuary who obligingly came and took it away. I thought that was the last I had seen of it. But later in the year this charity sent me its annual report. It referred to my fox and how they had nursed it back to health and, much to my horror, had returned it to the area from which it came!

My cats regularly got fleas from the foxes as they both liked to sleep in the same place under a very large sycamore tree. I thought I am going to stop this. The academic in me thought if Qin Shi Huang, the Chinese emperor of terracotta warrior fame, could have a terracotta army I would have an army of reconstituted stone gnomes to deal with this situation. I bought some fifteen garden gnomes which I placed closely packed together on the place shared by the foxes and my cats, thinking they would no longer be able to sleep there. Did that work? No. They just slept on top of the gnomes! Incidentally when my elderly cats later died I took great pleasure in getting rid of them. Some of the gnomes saw their way to the plant stall at CABAHS!

I am an early riser and weather and work permitting, as part of my daily fitness regime, I do some gardening usually about 30-45 minutes. The time is often spent clearing up after and repairing the damage made during the night by the foxes. Sometimes I take a quick rest and sit on my garden seat drinking one of my three morning wake-me-up cups of coffee. Often my ginger cat, Bonzo, would come and sit on my knee for a five minute cuddle. One morning a young cub having seen this came up to me, obviously thinking it was a cat it wanted to do the same. It wouldn’t take no for an answer and took some shooing away.

Angelas fox

Animals know instinctively if a human is an animal lover and none of the foxes are afraid of me. They come up to me and don’t take any notice of what I say or do. I have tried everything to get rid of them over the years. Including fox repellents. The only thing I haven’t tried is lion poo which I gather they don’t like. After the tulip fiasco I have decided to throw in the towel. I finally accept my back garden belongs to the foxes. I will just have to live with them, garden around them and make good after them. The only outlet I now have left for expressing my fox frustrations is boring my friends and social network with my woes.

If any other CABAHS members have gardening frustrations, problems or tales they want to get off their chests and give an airing why not send them to CABAHS for this webpage? Perhaps other members have similar problems. It’s said a problem shared is a problem solved. Some might even have an answer to them. Perhaps we could start a CABAHS Moan Corner webpage.

Angela B