Fireblight

 

Aucuba japonica - in a bad way

The first plant I put into this garden (relatively bare when we arrived) was an Aucuba japonica, a Japanese spotted laurel.  No particular reason, other than that it was going cheap and, being a large, colourful and easy-going shrub, was a good fit for a shaded spot where I wanted some shelter from the prevailing winds.  It’s now very large, but useful on the rare occasion when I want some variegated foliage for a flower arrangement (and it still provides shelter from those winds).  Over the summer, I noticed that it was looking very poorly, with brown and dying leaves; I gave it some water, assuming that the drought was affecting it, but it continued to look bad.

Brown bits on the Cotoneaster horizontalis

I also noticed that the Cotoneaster horizontalis by the cellar steps, an old plant that was here when we moved in, had brown tips to some of the stems.  This happened last year also; I cut the brown bits off and thought no more about it, but with a recurrence this year there was obviously a bigger problem.  Pondering the issue from the kitchen window, my eye travelled across the drive to where a hawthorn bush has self-seeded – and I realised that this wasn’t an isolated occurrence.  I had been uncertain what to do about the (now fairly large) hawthorn; with the neighbouring ash tree gone, having another tree nearby as a replacement was a good thing, although it was going to cast shade on the neighbours’ garden as it grew (this didn’t seem to bother the neighbours when I asked them, so I left the matter as something to deal with later).  But part of the hawthorn has also been turning brown and dead, and on closer examination even the bits that I thought were healthy are starting to show signs of disease.

So I sent a photo to the Royal Horticultural Society, and in due course the answer came back.  It’s fireblight, caused by a bacterium that attacks shrubs including cotoneaster and hawthorn (and apple trees, although I haven’t seen any signs of it on ours, fortunately).  And, looking around more widely, I can see traces of the same problem on the big cotoneaster by the drive entrance, and there’s a cotoneaster in a garden across the road that looks completely dead.  The remedy, such as it is, is to cut affected stems out and dispose of them carefully, sterilising tools as you go, although I think it may be too late to do anything for the hawthorn, which I will need to take out (somehow).  I wouldn’t be too sorry to lose the cotoneasters; they support a lot of wildlife (bees like the flowers and birds the berries) but they seed themselves too freely and there are some seedlings that I would be glad to be rid of!  However they’re useful plants for difficult places and not easily replaced with something else, so I’ll do what I can for them.

Fireblight also affects other plants that I have around the drive, photinia and firethorn (pyracantha).  They're not showing any signs of the disease, so fingers crossed.  However I recall that, some years back, the main part of the firethorn on the house wall died off, with symptoms that were very similar to what I've got now on the cotoneasters.  I managed to remove the dead part and grew on a healthy shoot in its place, and that is now a well-grown plant showing no sign of distress - but maybe that too was fireblight.

But is that the problem with the aucuba?  It’s in a different plant family, and not apparently likely to be attacked by fireblight.  They're pretty bomb-proof plants.  Now that the temperatures have started to cool (although the weather this week is set to be just above 20C, with sun) and we’ve had a few showery days, the plant is looking a little better; it may be enough just to cut out the really bad bits.  Perhaps it was the lack of water, or too much heat (they like cool, shady places); it can get scorched by hot sun.  Sunburn?!  I had taken some cuttings just in case – they are now in the greenhouse – and in the process discovered that the plant had layered itself on the shady side, and the layering looked healthy, so perhaps, if necessary, the original old plant could be taken out and the new one left in its place.

Cyclamen hederifolium

While I was investigating the aucuba to find healthy material for cuttings, I noticed that the cyclamen (Cyclamen hederifolium) in a weedy corner under the holly tree are in flower – a welcome autumn flower.