As autumn proper has arrived, and October is a mere gale and thunderstorm away, it’s a wonderful time of the year to enjoy the delights of Dahlias.Very late to the Dahlia party, I’ve realised that they provide a wonderful autumnal blast of colour in the garden, and with appropriate selection, are brilliant late nectar flowers for many insects. The downsides of them which have put me off in the past – being favourite slug fodder in early growth, requiring staking, and most seriously annual lifting of the tubers, because of lack of frost hardiness, have now been partly overcome.

We have fewer slugs these days, and if supported with other plants one can dispense with the staking. What’s really changed my view though is success with the species Dahlia merkii, since over several years it has proved reliably hardy overwinter in different parts of the garden, and is very easy to germinate from home saved seed.

So I don’t have to dig it up every autumn, and it’s easy to multiply. I’ve been unable to find out who merckii was named after, but like most Dahlias it’s native to the mountains of Mexico. Click here for a very good review on the excellent Dahlia Society website of the history of Dahlias in Western cultivation, and here for even more details about the interesting history of their discovery. It surprised me that the huge range of currently available hybrid cultivars have been developed from just 35 mainly conventional, single flowered, species.

As a consequence of the hardiness and fecundity of D. merckii, now that I’ve increased the numbers of plants we have, I’m beginning to spot subtle variations in the flower form of different plants. Perhaps it’s with the eye for flower detail that inevitably develops once one becomes a galanthophile. Since this year has been a wonderful year for seed formation, I’ve been careful to be less diligent in dead heading several of the plants in a serious attempt to grow a larger number and begin to select out a few favourite forms in the years ahead.

There’s even potential for an interesting hybrid of two, from the seed of those plants growing in a raised bed area, where they’re intermingled with Cosmos bipinnatus, Salvia ‘Amistad’ and Dahlia ‘Magenta Star’ – a lovely combination based on what we saw last year at Gravetye gardens, with the addition there of a Helenium. Sadly, the Helenium hasn’t competed with the other plantings, but all the D. merkii flowers in this bed are on plants germinated this year in February, showing what a very speedy result one can achieve for a modicum of effort earlier in the year.

The seed does need sowing in some warmth early on, and the young plants potting on and keeping inside the greenhouse until frosts are past, but the length of flowering time, up until first autumnal frosts is well worth it.

On a recent trip to the glorious treasure chest of exotic plants growing at Coleton Fishacre on the South Devon coast, we again spotted Dahlia merkii growing amongst a beautiful mix of perennials in a small rill centred walled garden area, close to the fascinating Art Deco house built by Rupert D’Oyly Carte and his wife in the 1920’s. They’d apparently sailed past and spotted a perfect setting for their home at the head of a deep valley heading down to a small cove on the Devon coast. We bought the planting list sheet for this area, and will try to track down the tender but beautiful Salvia leucantha ‘Purple Velvet’ (last photo below) to introduce a bit more vibrant colour later in the year. Click here  and here for more. (Apologies for a typically minimalist and information sparse National Trust web page).

Well worth a visit if you’re ever in that part of the world – if you can bear the traffic which made us again realise what a haven of tranquility West Wales still is. It’s also amazing how financially successful the idea of comic operettas was in the late Victorian era and for long afterwards. Gilbert (the librettist) and Sullivan (the composer) were supported by their producer Richard D’Oyly Carte, (Rupert’s father). In addition to this influential role, Richard built the Savoy theatre, (and also later the Savoy hotel), for their works to be performed in, and founded the eponymous company which staged productions of their operettas for over a century.

I have distant memories of watching my older brother Chris sing the principal role of Mabel in “The Pirates of Penzance” at school, before I sang a chorus part in “The Mikado“, and subsequently played my clarinet in the school orchestra for what was then a traditional Adam’s Grammar School annual pre-Christmas G&S school show.

I wonder if this tradition had been established a few years earlier and whether Jeremy Corbyn (JC) took part? It seems to me that the words of director Mike Leigh’s assessment of Gilbert’s approach to plot development, (below) suggest there could be a place for a revival or reinterpretation of some of the G&S operettas in today’s topsy-turvy world. Perhaps JC and BJ could feature? Or DT? I hear that Spitting Images is returning, but only to the U.S.A.

“With great fluidity and freedom, Gilbert continually challenges our natural expectations. First, within the framework of the story, he makes bizarre things happen, and turns the world on its head. Thus, the Learned Judge marries the Plaintiff, the soldiers metamorphose into aesthetes, and so on, and nearly every opera is resolved by a deft moving of the goalposts. His genius is to fuse opposites with an imperceptible sleight of hand, to blend the surreal with the real, and the caricature with the natural. In other words, to tell a perfectly outrageous story in a completely deadpan way.”

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In a previous post I hinted at a very good year for waxcap mushrooms in our meadows, and given the number I was seeing from walking our meandering upper hay meadow mown path, I thought a more detailed count would be worthwhile. It seems that our meadows are developing into quite significant bastions for these globally extremely rare and really colourful mushrooms, which I’m guessing many readers will never have seen “in the flesh” so please bear with my nerdy enthusiasm.

I began in our upper hay meadow with contour following passes across the field at roughly 2 metre spacings. This sort of “eyes down” walk is necessary to avoid missing any fruiting bodies, which otherwise can easily remain hidden amongst grass that hasn’t been grazed yet since the annual hay cut.

The numbers recorded have amazed me. The first effort on August 30th yielded 492 fruiting bodies in what I recorded as 72 distinct patches or colonies. The majority (over 380) were the vibrantly orange coloured Fibrous waxcap, Hygrocybe intermedia, above. Though 3 other species were present in smaller numbers, with a few unidentified specimens.

The equally bold and appropriately named Golden waxcap, H. chlorophana, above, was the next most numerous with 65 mushrooms.

Then 12 much smaller Glutinous waxcaps, H. glutinipes, above, and finally.

12 Citrine waxcaps, H. citrinovirens. 

Many of the smaller, younger fruiting bodies were only just showing through the ground hugging, mossy basal layer, which is present in most of this meadow. It seems that this is critical in creating a much warmer, and moister micro-climate for them to develop successfully. So don’t rake or scarify your meadows, if you want waxcaps to thrive.

We rarely find any in more recently mown areas. Apart from sheep grazing from October to early February, the upper hay meadow is un-grazed, and cut once, in stages, from mid-May onwards. It occasionally has wood ash spread on areas of it, and on two occasions had a light top dressing of dried seaweed meal.

Last year this meadow produced a heavy crop of field mushrooms, Agaricus campestris, from a different area of the meadow. This year, so far, I’ve only found 2 field mushrooms.

Most of these mushrooms are very short lived, so just 4 days later, many of the Fibrous waxcaps had disappeared or were shrivelling to a brown black, with perhaps just 29 new ones having popped up, although this was very subjective, being judged by the undamaged appearance of any “new” ones.

But I reckoned there were now an additional 124 Golden waxcaps and a further 16 H. citrinovirens.

Many of these mushrooms are quickly damaged by slugs, but since the “Beast from The East” in March 2018, and then the very dry summer last year, our meadow slug population is a tiny percentage of what it has been in the past.

We always start to see a few Fibrous waxcaps as we mow the field in sections from late June onwards, but it’s clearly impossible to assess just how many might be present earlier in the year, beneath the uncut sward.

I thought I’d weigh a few typical mushrooms, which seemed to average about 10 g apiece.

So maybe a standing crop of about 5 KG of waxcaps in this fairly small, less than one acre area, on just one day. Using Gareth Griffiths’ (the waxcap expert from Aberystwyth University) estimate that the biomass of typical fungal fruiting bodies is only about 1% of the total fungal biomass, that would imply about 500 KG of fungi in this meadow! Not bad for carbon sequestration either. And that’s just from these early species – no sign on this date of any Pink waxcaps.

With drier weather, a follow up count on September 11th yielded far fewer new mushrooms: Fibrous 30 in 15 patches, Golden – 18 in 5, Citrine – 9 in 3; Glutinous – 1 in 1; and the first Pink waxcaps, H. calyptriformis – 3 in 1.

After a wonderful sunny hot week in Devon, the rain arrived with a vengeance, and as well as a singleton of an additional species in this meadow, probably a Spangle waxcap, Hygrocybe insipida.

2 further species were found in our lower wet hay meadow. Firstly (probably?) Orange waxcap, Hygrocybe aurantiosplendens.

and also (probably) Pale waxcap, Cuphophyllus pratensis.

Yesterday in the rain, on September 28th, a hurried count in our steep small field which is only ever grazed by our sheep, and not cut for hay, gave a total of an astonishing 786 Pink waxcaps.

All this before we head into the peak waxcap month of October. I did find an interesting piece of work by Griffiths et al on how sward management can impact on waxcap populations. Click here for more. This seems to demonstrate that regular short mowing produced the highest numbers of fruiting bodies. It’s clear from the images in this steep sloping meadow that the Pink waxcaps seem to be performing very well in spite of the long grass in this field this year.

Two other interesting observations are that the different meadows, and/or their management seem to favour different waxcap species.

Fibrous waxcap predominates in the upper hay meadow, Pink waxcap in the steep sloping meadow; and currently Glutinous waxcap is the predominant species in the lower wet meadow.Our 3 other fields all have waxcaps in them, but currently not enough for me to justify the time needed for a detailed count.

Secondly, in both the steep meadow and the upper hay meadow, which have a very similar aspect and slope, the Pink waxcaps are predominantly in the lower third of the field, and generally away from the hedgerows. In the lower meadow, my passes from the upper, to lower parts of this meadow showed the following distribution of Pink waxcaps.

20 in 7 patches (Upper pass)

10 in 72

50 in 12

73 in 12

366 in 73

186 in 29

29 in 5 (Lowest pass)

 

My theory for this skewed distribution is that because our sheep nearly always spend the night resting or asleep at the top of these steep fields, there will be significantly more dung and urine deposited in these areas. Knowing how sensitive waxcap fungal networks are to high phopshorus and nitrogen, this may well inhibit fungal development in these parts of the fields.

A final thought.

How much do we really understand about grassland ecology? There are clearly huge biomasses of these fungi in our few “impoverished” upland meadows, with much locked in carbon, and probable interactions with the many other plant, microbe and invertebrate organisms seen, or unseen. And who knows about any impact on our very poorly understood moles? Such fungi were once common place in all our permanent pastures and hay meadows right across the countryside, before modern agricultural “improvements” and near ubiquitous fertiliser and slurry applications eliminated them.

Apart from the fleeting aesthetic beauty of these colourful autumnal crops, do we have any idea of just how “impoverished” and inadequate much of our grassland ecology is without them?

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A real treat this week was a trip which Fiona had organised with Stephen and Mel Lloyd for our local gardening club, Cothi Gardeners to visit the Hergest Croft garden for a combined guided tour and seed/cutting collection. We were really fortunate with a benign weather slot in what has been the wettest week for months, and were thrilled that Steve was so generous with his time and advice, whilst Mel provided us all with bags, and names to record the many seeds, fruit and cuttings we were able to collect in a two and a half hour walk.

I’ve written about Hergest Croft on these pages before. It’s such a special place with one of the finest collections of trees and shrubs in the British Isles including National collections of hundreds of different Sorbus, Betula and Zelkova, as well as being wonderfully peaceful and beautiful whatever time of year one visits.

Steve demonstrated it’s always worth cutting into a few seeds just to check if they’ve got viable white/green centres. Sometimes a tree will be laden with seeds which look fine, but are in fact empty and will never germinate. Also he pointed out some of the trees where it’s best to save seed from the tree (e.g. Acers and Sorbus) and others (e.g. Magnolias and Davidia) where it’s better to collect from seed or fruit that’s fallen to the floor.

Click here for more about Hergest Croft, and there’s still time to plan a visit for their special autumn plant fair on Sunday October 13 th. What I didn’t know before Stephen told us, as we walked through the garden’s glades and reached the top of the Sorbus collection, is that the garden rises to over 1,000 feet above sea level, so many of the well labelled trees which are indigenous to China and the Himalayas will be quite comfortable with the conditions here.

Stephen, the Head gardener in a team of 5 who manage the 70 acres, has worked as a gardener at Hergest for 40 years, and has grown many of the now mature and rare trees from seeds sent to Hergest from collectors around the world. So to have him passing on his tips as to how best to choose and propagate material was a rare treat, and all this in a year when many trees were laden with berries and seeds after a bumper year for pollination and fruit production.

Thanks very much to Stephen and Mel for their very warm welcome and generosity and for making it such a very special day. We look forward to letting them know in due course how well we all get on with the propagation, once we get all the material prepared for sowing.

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Finally, a delight to see one of our most recently planted Hydrangea apsera group shrubs has flowered for the first time this year. And what a stunning plant it is. I think it’s H. aspera Kawakamii group. I hesitate since there’s a little confusion with our planting records! Remarkable both for the size of the flower heads, its typically large hairy leaves, and also that it flowers much later than many other forms, so should last well into October.

It also looks like it could end up being several feet tall, when it’ll become a brilliant late pollen source for any bees still out and about.