I get a bit miffed when the media get hold of a piece of news and make such a fuss about it and breed hysteria just to sell more. As it was with fungus Chalara fraxinea, which causes ash dieback, earlier in the year. Now ask anyone about plants and they will know practically nothing about them but they will be intimately acquainted with ash dieback and the fact that this foreign-imported disease will kill all of the UK beautiful native trees…

I am told the same happened in the 70s with Dutch elm disease (so media-worthily shortened to DED) caused by fungi of the genus Ophiostoma. A friend was so surprised to see some elm seeds a while ago that she did not immediately identify them as such: she had unconsciously assumed there would not be literally any left…

It is indeed a serious matter when a new pest, disease or invasive species is introduced in a new area. And Chalara is a notifiable disease, so if you spot it anywhere in the UK, you have to report it. What annoys me is the tones, as if it was not our very own fault, the fault of human activity, that is. It often is. In this case, one of the ways into the country for the fungus was likely that we imported trees from foreign nurseries because it was cheaper than growing them here.

There are other famous cases of imported “aliens”. For example in the case of Fallopia japonica, or Japanese knotweed, which was highly prized for its garden worthiness in times past – fancy that, we are today introducing, to deal with that problem plant, a pest that is non-native too: insect Aphalara itadori… suspending judgement on that.

Anyway, apart from getting miffed, I have started looking around and spotting ash trees. Fraxinus excelsior is indeed a beautifully graceful tree, with dark pinnate leaves and bunches of winged fruits in summer and autumn.

Scientists across Europe are on alert and mobilised trying to find resistant specimens (there seem to be enough genetic diversity in the wild for that to happen) in order to understand what makes them so… they have also suddenly broken into the 21st century social media world by creating Facebook application “Fraxinus”, to harness the power of the crowd in identifying gene sequences…

Fraxinus excelsior ‘Stricta’

Back at work, today it was team day and we worked on the tree circles in and around our Fraxinus collection, so I had the opportunity to observe some close up.

Fraxinus americana ‘Autumn Purple’

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Fraxinus paxiana

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The first thing I noticed is that not all ash has black buds like the F. excelsior species: they are all actually quite different in colour, ranging from pink to orange-brown and to black.

Fraxinus sieboldiana

Fraxinus excelsior

Fraxinus mandschurica

A fascinating journey, literally through a world of plants, at the end of which I got to pick my favourite: Fraxinus ornus, known as manna ash, which hails from South East Europe, with its dark green foliage and bright green seed. It has beige buds.

Fraxinus ornus

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Was finalising the stockcheck of bed 435-03 today, which is Spirea central. This is one of the tidier beds, with plants well within their own boundaries for the great part. But a couple of the labels on the Spireas got mixed up, so I had to undertake a bit of investigative work.

Internet at the ready, I started to observe the plants. Luckily, most are flowering or have dead flower heads still visible, because the leaves of Spiraea, albeit all different, are often only slightly so. The flowers are a bit easier to interpret. There are two main colours: white and pink (which is either pale or bright) and two main inflorescence types: corymb (flat) and panicle (pointed). At the very least you can spot whether a label matches the species’ combination of colour and inflorescence type or not, in which case the plant might need verification.

And that way I found a pink panicle Spiraea that was carrying a white corymb one. And also found a mix of pink and white flowers in the same shrub, which, after a good look at the leaves, told me that some suckering shrub had expanded into their neighbour. All the notes I am taking are going into my stock check, which I hope will help my colleagues restore the beds to their glory.

S. crenata

They are starting to grow on me, Spiraea, and some are really lovely, such as the S. crenata in the picture, with white flowers, dentate obovate leaves that become dark green when mature, and reddish stems. It originates from the Caucasus and is not suckering.

S. chamaedryfolia ‘Transiens’

Or even the suckering S. chamaedryfolia ‘Transiens’ with white flowers and larger, dentate ellliptic leaves, more similar to a Neillia or a Kerria.

Here are a few more – enjoy.

S. virginiana

S. x fontenaysii

S. formosana

S. betulifolia

S. douglasii var. menziesii

S. nipponica

S. japonica var. acuminata

S. micrantha

I have spent the last two days dealing with a massive plant of Prunus laurocerasus I had my eyes on since shortly after I started on the South Canal beds.

Bed 437-02, as it is known to the Kew-initiated, had two massive prostrate species of Prunus: laurocerasus and laurocerasus var. salicifolia. We had tackled the P. salicifolia with the 3rd year student earlier in the season, which took a little more than a day but was very satisfying to do.

Prunus laurocerasus var. salicifolia after pruning

The other day, after talking to my manager, who mentioned we should cut back all the plants that are straying into the grass, so that sward can mow the lawn without obstacles, I decided to give the other Prunus a go on my own, even though it was a bit daunting. It was useful in order to finish once and for all my stocktaking of the bed as well (I have already done the preliminary round here).

It took me two days, with the exception of some time spent weeding, and I still need to tidy up and rake the dead leaves away.

It was, in fact, a massive task, some 5 load-fulls went to the compost heap, and stems up to 15 cm had to be cut with a saw, so that I am pretty tired at the moment, but it looks so much better now: it’s airy all around and no more Spirea are swallowed by the Prunus‘ overgrown branches – I’m proud of it and tonight I showed it to a friend that came visiting (poor thing, putting up with all my excitement for these plants, their shape and health!).

I forgot to take “before” pictures, except a couple, but do imagine it extended all the way into the Spiraeas on all sides… it was such a large area that I did not even manage to take proper panorama pictures!

Before, internal side

After, internal side

Before, external side (note also the intruder Aesculus weed grown to considerable size)

After, external side

An overview of the end result, external side of the bed (slightly deformed pic)

Panorama of the internal side of the bed (click to enlarge)

P. laurocesarus is a plant I know well, as both my parents and auntie had it as a hedge all around their houses, and I have grown up with it. It is a very tough evergreen plant, whose leaves are very resistant to decay, and it grows so thick that it shades anything out. The one I tackled formed such a dense mat that it provided shelter for a range of wildlife: a badger sett and two old birds’ nests is what I found… and I suspect there’s more under the huge plant that is still left!

One thing that I did not remember from growing up, and that made me curious was that the stems I had cut were easily ringbarked, as the bark (epidermis + phloem) peeled off, leaving a rather smooth, and sticky, xylem surface. The phloem, on the other hand, was spongy and reticulate.

Ringbarking P. laurocerasus: xylem, phloem & epidermis

Phloem meshy tissue

Phloem tissue: layers visible

Only four weeks to go, now, and still so much to do…