Garden words: The January Review

Wicked Bugs

Amy Stewart

There are some books that just make you go 'Well. I never knew that.' And then there are books which make you say it over and over again, to the point where you start bringing up random facts in conversation with friends and family, just to get them out of your head, and when those facts happen to be about small and often fearsome things with a lot of legs your friends and family quickly start looking at you a teensy bit oddly.

Did you know, for example, that British diplomat Charles Stoddart was condemned to spend four years being eaten alive by blood-sucking assassin bugs while held captive in an Uzbek bug pit in the mid-19^th century?

Or that there is a caterpillar in south America so venomous that if you happen to tread on them barefoot you suffer massive internal bleeding and organ failure? Or that the crew who sailed to America with Christopher Columbus were driven so mad by the chigoe flea, which buries itself under a toenail and lives out its life there, that they cut off their own toes to get rid of it?

Nope, nor me.

You will have guessed by now that 'Wicked Bugs' isn't, strictly speaking, a gardening book, but since we gardeners spend such a lot of our time either encouraging in 'good' bugs (ladybirds, lacewings, hoverflies) or murdering 'bad' ones (aphids, caterpillars, whitefly, slugs: the list goes on... and on...) then a book about them can only be endlessly fascinating.

There is a section on garden pests which is... well... almost as interesting as the ones about sailors and armies (did you know some used to throw clay pots full of scorpions at advancing Roman troops, circa 200AD, by the way?) though it does suffer a little from a sudden outbreak of advice-giving. I did think the bit about aphids was horrifying though: apparently one female aphid is born already containing within her the beginnings of a 'daughter' who is herself already pregnant with a third generation. Wow. That explains a lot.

Others, though, like the terrifyingly efficient Colorado potato beetle, are given a section all their own, so dreadful are they. The Germans thought the US Army was waging biological warfare by dropping Colorado beetles on their heads from planes during the Second World War, you know.

And so Amy Stewart gambols on through tales and titbits so surprising, arresting and downright gut-churning that I have been glued to this book ever since I started on page one. I love her obvious delight in her subject and her ability to tell a good yarn; she has a talent for winkling out little snippets of unfeasibly extraordinary information and using it to grab you by the ears. I just wish I knew how she finds out this stuff.

Little niggles: this is an unremittingly American book, to which you have to adjust yourself and stop chuntering about early on. Sometimes that's a good thing: I've always loved the American ability to find an original turn of phrase (no clichés here).

But there's a general assumption that the reader's attention is wandering off all the time (surely impossible given the content of almost every page), so we've got silly little 'pull-quote' things repeating choice bits of a paragraph in a larger type, presumably to titivate the reader but which end up interrupting the flow. I trained myself to ignore them.

Otherwise, though, the book is a gorgeous little thing: I loved its styling as a battered field notebook, and the line drawings and etchings by Briony Morrow-Cribbs are simply exquisite and a master touch.

Amy already has a more plant-oriented book out, 'Wicked Plants', all about poisonous plants, and it's now on my must-have list. Incidentally. you can read a bit more about the book in Amy's own words on the BBC Gardening blog.

Not the colorado beetle

My poor new potatoes are suffering a nasty attack of early blight. Not quite as nasty as late blight, as the tubers don't seem to get particularly badly hit, though the top growth is looking decidedly anaemic, not to say acne-ridden.

But that's not what was worrying me this morning. As I bent to the fork to hoick the next lot of 'Foremost' into the colander I spotted this pair clamped to a leaf.

'Oh, my goodness,' I thought (or less printable words to that effect). 'I've got colorado beetle!'

This is one of the alien invaders that everyone's very, very nervous about. They skeletonise potato plants (and tomatoes, and aubergines): if you think blight is bad, it is as a minor sniffle compared to the colorado beetle.

The pest is established in France already: it can only be a matter of time before it skips the Channel. It's certainly notifiable.

Now, normally the internet has just one function in these circumstances: convincing you that the headache you've suffered from all day is not a hangover but a terminal brain tumour. For once, though, it served to calm an over-heated imagination and demonstrate that actually, what you've got is rather less alarming than what you thought you'd got.

So on my way to the Defra website to send a panicky email to the appropriate authorities I discovered that this is what a real colorado beetle larva looks like.

(Released under commons licence)
As you can see, nothing like my little fellas. However the question remains unsolved: they are ugly little blighters and keep reminding me of ticks with the way they're squat and tenacious and hold on with all their feet at the front. Here's another pic.



So - any ideas? What have I got here? And should I - as I suspect I should - be doing something about them? Answers on a postcard (or failing that, in the comments section) please...

Bzzzzzzz

Look what we found on our kitchen wall the other day.


Apologies for the quality of the picture, but if you've ever tried to take a photo of a fairly small insect while balancing on one foot on the kitchen sink you'll find fuzzy photos are hard to avoid.

This is a hornet, Vespa crabro, our largest social wasp. This is quite a little one, as it happens, though it's about twice the size of a regular wasp. And just look at that pointed nose: straight out of Bug's Life, don't you think?

I think we must have a hornet's nest not far away as we found a proper grown-up one of these buzzing extremely loudly and angrily against our skylights not so long ago as well. That one was seriously enormous: a good couple of inches from nose to tail.

Everyone I have mentioned this to has immediately gone into a 'don't panic!!' routine quite worthy of Lance Corporal Jack Jones. In fact, though, I think hornets suffer from a bad press. They are accused of everything from stinging people viciously with no provocation to ripping off the heads of poor innocent little bumblebees. Unfortunately for them, this is a recurring case of mistaken identity, with a good dollop of ignorance thrown in. This is a particular shame as they're actually quite rare, and what's more they eat loads of nasty garden pests - including aphids and caterpillars.

In fact, hornets will only sting when quite severely provoked: on the whole they are quite docile creatures. You're far more likely to be stung by a conventional wasp (which is a spiteful little creature much less deserving of sympathy).

And as for the ripping the heads off bees thing: that's not this hornet. That's the Asian hornet, Vespa velutina: and now that's an insect to strike fear into your very heart. Fortunately you're unlikely to see one in the very near future, as although they've made it to the south of France (where they are ripping the heads off honeybees even as I write, no doubt) they haven't - quite - made it here yet.

However, it is probably only a matter of time: the flood of insects arriving on our shores, largely hiding in imported plants arriving in our garden centres and therefore our gardens, is reaching plague proportions (step forward, citrus longhorn beetle, oak processionary moth, harlequin ladybird and the now ubiquitous lily beetle). They reckon we've got about 10 years before the Asian hornet arrives: when we, and no doubt their relatively harmless European cousins, should be afraid. Very afraid.

Plant of the month: August

Lilium 'Original Love'

At the risk of sounding a little, well, unfeminine...... Phwoooooaarrr.

We've been watching this one unfurl for the last two weeks like a slow-motion porn film. First the long, fat green buds began to pout and swell. Then they gradually darkened and a deep wine-red stain crept up like a blush. Finally, a few days ago, the first one burst: one petal, then another, then they all peeled back to reveal the most voluptuous, sultry, seductive flower you can possibly imagine. It is almost embarrassing in its suggestiveness: impossible to miss, impossible to ignore, quite possible to fall in love with.

It's an L.A. Hybrid: I'd always thought that meant they were bred by some fanatical britches-wearing and probably bespectacled American lily-grower in Los Angeles, but in fact it turns out the L stands for longiflorum and the A stands for Asiaticum. Much more proper and with a certain RHS correctness about it. That'll teach you to get all romantical then.

That gives you a tall (mine's about 4ft), sturdy, hardy lily that's pretty much trouble-free: heck, if I can grow it, anyone can. This one hasn't even suffered the usual attack of the lily beetle. I've had to harden my heart against these pretty red bugs so that I could squash them: I had less trouble with their larvae which have the attractive habit of covering themselves in their own excrement as they sit munching your lilies.

At the moment I'm betting that my LA hybrid's escape has been less to do with their in-built lily beetle resistance and more to do with the fact that I didn't get around to planting them until late May - by which time the beetles had done their worst to my earlier hardy lilies. I didn't realise lily beetles had only one generation but it appears to be so, and I've murdered the one in my garden. So there.

But anyway. This otherwise ravishing plant does have one downside: in all that hybridising and fiddling about they forgot to leave the scent in (mind you, try telling that to the bees bumbling drunkenly about in its abundant nectar). I have to say, if you're going to do boudoir, you do need it to be at least a little bit perfumed. However, it's imperfections that make you perfect, isn't that what they say? And for such a luscious, seductive, and downright sexy colour I will forgive anything.

Mystery blobs

Any idea what this is?


Found all over some small silver birch trees, while we were rambling about the countryside with assorted small children recently.

They come in clusters, too:


My first thought was, ah - it's a gall. The leaves are of course obviously somewhat chewed. But when you pick them off they're rock hard - and they have hollow innards. And besides, birch gall looks like this, which is not at all the same thing.

I was a little sad to find that it wasn't the rather wonderfully named silk button spangle galls: they look like this:


(the pic is from the compellingly interesting Tree Blog which is following the lives of about 25 trees from seed up, and has an alarmingly comprehensive selection of disease-related pictures to show for it. It actually made me wonder how any tree actually makes it to maturity.)

So - any ideas? I'm still with the galls idea, but am intrigued to know what might have caused this and how. They're very pretty, but clearly not doing the tree any good at all.

Over to you?

Oy! Gerroff me geraniums!

Would you just look at this?


This has been going on for a month now, and at first I put it down to a bit of frost damage - this is Geranium maderense, after all, I'm trying to coax it through the worst winter since I were a nipper, and despite the best efforts of my little fan heater it's still a bit parky in the greenhouse.

But then I arrive for a quick check round this morning and....


Now, I think to myself, if it weren't January and a foot deep in snow outside and minus 7 at night and generally BLOODY COLD I'd think that was caterpillar damage.

Nah.....

Oh yes it is. A closer inspection revealed a small but nonetheless inescapably green caterpillar munching away at my geraniums. Not just this one but also the overwintering pelargoniums which are losing their leaves not through the usual culprits of downy mildew plus a touch of the chills, but blimmin' cabbage white caterpillars. In winter! In a seriously cold, frosty winter!

With a yelp of horror and outrage I'm afraid I chucked the culprit out of the door into the snow in a fit of vindictiveness and it was pounced upon by the chicken so I don't have photographic proof, and you'll just have to take my word for it. A good hunt through has not revealed another one.... yet. But my dander is now up (whatever is a dander, do you think?) and I shall be inspecting with an eagle eye every morning from now on. I also crushed a couple of sleepy aphids and a blackfly while on patrol, so clearly letting your guard down on pest control isn't on the cards even in this weather. Is there no rest, I ask you?

Incidentally in case you're wondering what cabbage whites are doing eating geraniums: if they can't find cabbages then pelargoniums and geraniums are fair game for all the brassica caterpillars as I discovered a couple of years ago when a big brown caterpillar eating a client's pelargoniums was a cabbage moth caterpillar. So pelargoniums taste like cabbages. Apparently.

And here's a bit of advice: don't grow calabrese in your greenhouse. Even if you've grown too many seedlings, can't bear to throw them away and it's the only place you've got left. Especially in a record-breaking caterpillar year.

Harrumph.

A tale of gardening failure

My poor apple trees.

I was raking up the leaves they've so generously been scattering all over my chicken run, and to relieve the monotony (and the ache in my shoulders) decided to have a closer look at them - something I don't do nearly often enough.

I found them etched with a sorry tale of years of callous neglect from their excuse for a gardener. I'm afraid that since they are in the chicken run, they're something of an afterthought at the end of the garden and I don't pay them anything like as much attention as I should: the constant and tender cares of better orchard-owners than I are sadly lacking here, and though they try to soldier on as best they can, they're clearly showing signs of strain.

It doesn't help that the person who planted them - not me, I hasten to add - put them far too close together: I have four standard apple trees, two Bramleys, two Cox's, about 10ft apart in a square. That's about half the room they should have, so they're at a disadvantage before you even factor in the slacker gardener who's supposed to be looking after them.

Here, like a doom-laden encyclopaedia entry of afflictions for apple trees, is what I discovered:

1. Woolly aphid

Like cotton wool balls sticking to the bark. There are little critters under there, sucking away joyously at the sap of my apple tree. I've seen this covering an entire tree in someone else's garden, so it can get to epidemic proportions: luckily I've only got the odd fluffball or two.

Treatment: I'll be getting out the hose with the spray set to 'jet' this spring: you just zap the suckers away and keep doing it till they're gone. Very satisfying.

2. Brown rot

Actually I did know I had this problem - I just haven't done anything about it. The apples go disgustingly brown and pustulent while still on the tree, and then - key to identification, this - they stay there, mummified. If you leave them, they'll infect healthy apples next year.

Treatment: do the exact opposite of me and pick them off as soon as you see them. Get rid of them in the bin, or burn them: don't put them on the compost heap.

3. Squirrel damage

This suspiciously regular area of bark damage is characteristic of a visit from one of those furry-tailed rats we're all supposed to find so sweet. As you can see, it's eaten away the bark right around the branch, cutting off the water and food and killing the branch. Still think they're cute?

Treatment: Letting rip with air rifles is, for some inexplicable reason, frowned upon in our semi-suburban street. The dog is, uncharacteristically, some help here: though the main purpose of wildlife in his opinion is to provide him with merry chasing opportunities, he does share our opinion of squirrels and they're the one and only thing on which he occasionally sates his inner wolf. However, he's also a bit thick so they outwit him all too easily and laugh their squirrelly laugh at him from on high. I think this is one bit of damage I'm just going to have to put up with.

4. Canker?

I really hope I'm wrong here, but it's not looking good. Apologies for the lousy picture, but I was in a state of shock when I was taking it.

Canker is the one thing apple growers fear to see. Sunken patches of bark like this, where the branch above the patch has died back (as was the case here) is a sign of a fungal disease that can kill the entire tree if you let it spread.

Now, before panic sets in, I'm not entirely sure this is canker. It's a bit long and thin - cankers on apple trees tend to be rounder, like the horrific picture on the RHS advisory service page on the subject (now there's a sight to strike fear into an apple tree's heart). On the other hand, there's no denying that there has been considerable die-back above the area.

Treatment: I can feel an extensive programme of winter pruning coming on. The organic way of dealing with canker is simply to cut it out: and if this is canker, it's very much at the early stages, with only small branches affected and nothing on the trunks or major branches - so I've still got a chance to get rid of it if I act now. I'll be cutting back at least a foot or so behind the canker into healthy wood, and again - I'll be burning the wood, not leaving it lying around to re-infect healthy areas. And even if it isn't canker, I'll have given my languishing apple trees the first TLC they've had in oooh..... this many years.

And then I shall assuage my guilt by pampering them in an over-compensating sort of way all year. Before lapsing next winter some time into my usual state of distracted forgetfulness, of course.

I think I shall go and become an accountant now. Goodbye.

Early autumn

You'd be forgiven for thinking this was an example of lovely autumn colour. It's a horse chestnut tree not far from my front door.

Unfortunately, this rather fine example of a field maple (I think) right opposite will tell you it's not quite time for autumn yet:

As you can see, still in its summer finery.

Around here all the horse chestnuts took on an autumn colour in about August - you could tell which trees in a hedgerow were chestnuts as they were the only ones which were bright yellow. It was the same story last year. If you look more closely at the leaves you can see the colouring isn't anything to do with autumn at all.

This is chestnut leaf miner damage. It's caused by the larva of a moth which has become absolutely rampant in the south-east of England. It comes from southern Europe, and until recently was minding its own business over there, but in 2002 the first ones crossed the water and turned up here. I believe it's now making its way north.

The Forestry Commission are keeping an eye on it, and they've asked people to let them know if it appears in places where it hasn't yet been seen (a few more dots are ominously appearing on their map each year). Apparently, dramatic though it looks, it doesn't do any damage to the tree, though if it appears at the same time as a nasty bark disease called bleeding canker the combination can be fatal.

It seems to me, though, that if you completely defoliate a tree every year for a number of years, it can't do it much good in the long run. I love horse chestnuts - like most people I played conkers as a kid, and I love the fact that they're so big and strong and sort of ancient English forest-y. They're the sort of trees you use as landmarks, the sort of trees you rely on for your sense of identity and place. So to see them all looking so sick, so early in the year, makes me fear for their future. It feels all wrong, like daffodils in December. If this is global warming, you can keep it.

I've been got

I thought it couldn't be long - especially with the summer we've just had. Blight has made its first unwelcome appearance on the allotment.

The first you see is a few little harmless-looking brown spots like these.

The spots just get bigger and bigger...

... until they start destroying whole leaves, then the stems too.

Finally the poor potato plant ends up looking something like this - every leaf shrivelled, every stem brown and sick-looking. You shouldn't let things get to this stage: when you first see the leaf-spots, remove the foliage completely, as rain will wash the fungal spores down through the soil and onto your potatoes otherwise (and you've never smelled anything bad until you've smelled a blighty potato).

The above photos were all taken on the same morning, of the same patch of potatoes ('Desiree', in case you're interested) so it just goes to show that blight comes on in stages, and some bits can be worse affected than others.

Anyway - so now all those stems have been cut off at ground level, bagged up like toxic waste (never compost them - the spores overwinter) and thrown away. I haven't quite dared lift the potatoes just yet: partly because I haven't had the time, but also because I detest the slimy mess of a blight-infected potato slightly more than I detest cleaning my downstairs loo. So both tend to get left for a long time in the spirit of procrastination (which in both cases generally just makes the problem worse).

One last thing - these are my 'Sarpo Mira' blight-resistant potatoes, on the same morning, growing just eight feet away:

This has deepened my admiration for this spud variety even more. It's a good roasting spud, though people say it falls apart if you boil it so it's steaming only. Anyway, from now on I'm making them a regular on my seed spuds order - when potatoes grow this well when blight is rampant all around, it's daft not to.

Hasta la vista, ratties

This is a cob on my sweetcorn the day before I got my two feral cats to keep down the rats and mice:

Sweetcorn is an irresistible favourite of all things verminous, and I've never yet managed to get any to maturity, even though I still plant it (more in hope than expectation). It always, always ends up like this - scoffed by either rats or mice, or both, before it even gets ripe.

Now this is how the rest of my sweetcorn looks, a couple of weeks after the cats were let out of the shed:

Oh, my... I am too excited for words. I think I may be about to harvest my first-ever home-grown sweetcorn cob after four years of growing the stuff.

I think it can be said that the cat as mousetrap experiment has worked. Outstandingly well.

(the cats are having a great time too... :D)

It's a cabbage moth!

Remember those caterpillars I found on my client's pelargoniums?

Well - thank you to all who replied. Plant Mad Nige offered a tentative ID as an Angle Shades Moth - but here's the pic of their caterpillars from the RHS's advice sheet on the subject:

(image: Tim Sandall).

Not really very similar to my little critter:

But enter the RHS's Principal Entomologist (no less), A J Halstead, who suggests my little friend is a rather more humbly-named Cabbage Moth - aka Mamestra brassicae. I looked this up on UK Moths - and sure enough:

(picture (c) Dave Griffin)

I think we have our culprit. Sadly he is a culprit, too - the moth is described as a "notorious pest" on UK Moth's info page on the subject, scoffing not only all members of the brassica family but clearly pelargoniums too.

Still - I love solving a good mystery. Now I have to go murder a lot of rather pretty caterpillars...

Canna blues

I was so pleased with the big canna I bought at Chelsea for a fiver... but look what's happened to it.

It was a bewitching shade of purple and green back in May (you can see a leaf that's more like what it should look like in the background). And it was in a gold medal winning garden. Just goes to show that even RHS judges can be wrong sometimes.

Now I'm not a canna expert but I'd say this was a virus. I was talking to the nice man at Hart Cannas earlier this year for an article, and he tells me virus is rife in the canna industry - in fact it's got so bad that it's far more likely that a canna you buy will have a virus than not. Apparently it's all because a shipment of cannas to the UK from the Netherlands was riddled with it, and it's spread like wildfire ever since. At Hart Cannas they're actually starting again from scratch, breeding their own virus-free stock: they don't have a lot yet, but it's building up and I think may soon be the only refuge for those who like their cannas without horrible streaks, mottlings and leaf puckerings.

The only option for me with this one is to dig it up and burn it. Rats.

Mystery caterpillar

Can anyone identify this little chap?

One of my clients asked me to have a look at some bedding she had in her front garden, which she thought had been clobbered by slugs. The odd thing was, it was mostly pelargoniums, which in my experience aren't that tasty to slugs so generally don't suffer much damage.

It was pretty clear as soon as I looked at them that this wasn't slug damage - no slime marks, and the holes were large and in the centre of the leaf - not like slugs at all, which usually attack the edges of leaves first and then if they are going to eat the centre of the leaf, they kind of scrape away a thin layer to begin with rather than eat it straight through all at once.

Anyway - it was all screaming caterpillar to me, so I hunted around for a bit and sure enough this is what I came up with. Trouble is, I have no idea what it might be - I'm not exactly an entomologist and my garden experience with caterpillars is limited to gooseberry sawfly and cabbage white butterfly caterpillars, both of which I can identify at a hundred paces and despatch accordingly.

I'm a bit concerned though that this little chap might be something interesting. I had a look on the pragmatically-named What's This Caterpillar website but despite a happy hour browsing their gorgeously illustrated plates couldn't come up with a conclusive ident - the closest I got was the unfeasibly rare Orache Moth.

Thinking it rather unlikely that we've turned up the kind of thing you send to the Natural History Museum, I sent these pics in to Wisley's advice centre to see what their bug people can come up with. But if there's anyone out there who's looking at this and thinking to themselves, "Doesn't she realise that's a pelargonium leaf-stripper?" please don't hesitate to enlighten me! Until then, we're holding off the spraying/squashing/nematode treatments in the assumption that it's innocent until proven guilty.

Meet my mousetraps

I don't know why it is that none of those worthy tomes about growing things on allotments ever talk about mice and rats - but in my experience, these twin scourges are second only to slugs in terms of what damage they do to crops. This year their tally includes my entire early pea crop, eaten to the ground when just seedlings, and now the first of my sweetcorn cobs to ripen.

I've tried everything: humane traps (they laughed scornfully and nicked the peanut butter while holding the door open with their tails); home-made not-very-humane traps (sweet jars sunk in the ground - they find their way in and then can't climb out. Trouble is, the rain gets in too and then they drown - I don't hate them that much); and not-at-all-humane traps (the conventional kind: once again, scornful laughter, no peanut butter and no dead mousies).

So it's time for the nuclear option. Meet my new mouse traps.

Mousetrap No. 1: aka Sweep. And...



Mousetrap No. 2: aka Sooty. This is about all I've seen of her so far - she hides under the soil sieve in the corner nearly all the time - and Sweep, though more courageous in that she'll come out if you've got a tin of cat food in your hand, isn't exactly trusting.

These are feral cats - I got them from the Cats Protection League after reading that they were very short of homes for these basically wild animals. They aren't pets, which is of course what most people are looking for when they want to rescue a cat - so they need people with outhouses, barns, stables or in this case sheds on allotments who can look after them but don't expect them to be very domesticated.

As far as I'm concerned, they're working animals with a job to do. Doesn't stop me being a bit soppy about them - they're very cute as they're only about 6 months old and have that kittenish look still - but I don't try to stroke them. I let them out for the first time this weekend - until now I've been keeping them in the shed so they know where home is - and am now keeping my fingers crossed that a) they'll come back and b) they'll massacre the mousies. And I hope rats, and possibly even bunnies too. Oh, I may be an animal-lover, but where my veggies are concerned it's war.....

Don't Panic!

One of my clients has a small but much-loved bay bush as the central focal point in a rather pretty little raised herb bed made of sleepers sideways on in a diamond pattern.

She rang me the other day in a right panic, insisting it was dying. It's always suffered mildly from vine weevil, which we've been keeping under control with a drench - but she was now convinced the little beggars had got it. So I promised to go and have a look.

The trouble with diagnosing plant problems is that it can be a bit like looking at those medical dictionaries which convince you that every time you have a headache you're about to die of a brain tumour. I realised as soon as I saw our little bay tree that it was a long way from dying - but then I started double-checking, just to make sure, and came up with a whole hypochondriac's litany of ailments, any one of which could turn out to be fatal.

Yes, there were plenty of glossy green leaves on it, and if you looked in the centre of the bush it was a deep, healthy green with lots of dense young growth. My client had panicked over some patches of yellowing leaves, which were rather undeniably a nutrient deficiency, and more specifically nitrogen deficiency. Remedy: a dose of liquid feed once a week until it's perked up a bit. Nothing more serious than that.

But look... some of the yellowing leaves have dark brown edges... and a curious dotting all over them. Hmm... I wasn't aware that bay could get rust, though that's exactly what it looked like. I decided I'd better look it up, just to be on the safe side.

Big mistake. Much like picking up that medical dictionary, I now have half-a-dozen horrible fates to consider for this poor little tree. It might have bay sucker - a mite that causes the edges of leaves to blacken and curl over. No curling on the leaves of my bay tree, mind, but then it might be early days... Now I discover that there's a new pest of bays, called bay rust mite, which only arrived on our shores last year after migrating from its usual home in the Med. As I read about black necrotic spots on the leaf surfaces I got really quite excited - rare diseases are almost as much of a buzz to discover as rare plants. Unfortunately (or fortunately, for my client) I discovered a picture of them on the Central Science Laboratory's plant newsletter - and it looks nothing like my bay leaves at all.

So for the moment I'm keeping my fingers crossed and betting on the odds-on probability that all we have here is a hungry bay tree with a mild vine weevil problem. I'll dose it with vine weevil killer again and give it a nice slosh of seaweed pick-me-up and see if it turns the corner. If not, I'm afraid it may be terminal.

Horrible diseases

Here's something to strike fear into your heart: first box blight laid waste to our clipped hedge topiaries, then it was sudden oak death threatening the most English tree of them all. Now that stalwart of the English garden, the fuchsia, is under threat from a new bug, the fuchsia gall Mite.

It's been spotted in Hampshire and causes twisted, distorted growth at the end of fuchsia shoots and branches. Let's hope it doesn't get much further - fuchsias may not be my favourite plant, but they're good-looking, dead easy to look after, I grow lots of them in various gardens and we'd all be poorer without them.

Camellia problems

I was up in the 3/4 acre woodland garden I look after the other day, and cutting back a camellia which was overhanging the pathway quite badly (this is the kind of thing I spend most of my time doing in this particular garden - the amount of green waste I remove from there has to be seen to be believed!)

I noticed pretty quickly that behind the curtain of fresh green leaves there was a problem. All the older leaves were covered in a sticky, black sooty mould, which not only looked nasty but also couldn't have been doing the shrub much good.

I wasn't quite sure myself what was causing it - I thought aphids of some sort, since this is what causes it on roses (the aphids secrete honeydew, which drips on the leaves below and is consequently colonised by the fungal sooty mould). I was a bit unsure about this since I've never heard of aphids attacking camellias to any great degree.

Anyway - I came back and looked it up, and thanks to the dear old RHS I discovered we almost certainly have not aphids, but Camellia cushion scale.

I have to go back and check whether there are yellow-brown scale insects near the veins (or indeed "white waxy egg masses"). But everything else fits.

The good news is, this is just the right time of year to control it. I'm going to have to spray; I'll try the organic version first (Growing Success Bug Killer or Vitax Organic 2in1) and if that doesn't work, I'll zap it with the very un-environmentally friendly Provado. My client tells me he has a backpack sprayer in his garage (the shrub is about 15ft tall) - so time to tog up and do battle!

Rhododendron problems

One of the gardens I look after is a woodland garden of about two thirds of an acre, where every plant seems to be about 20 feet tall. It's lovely - but I do seem to find myself doing a lot of pruning!

They've developed a terrible problem with rhododendron bud blast - a fungal disease thought to be spread by a leaf hopper. The leaf hopper is harmless by itself, but lays its eggs by making tiny slits in the buds of rhododendron flowers - which then becomes an entry point for the bud blast fungus.

You can tell bud blast because the buds turn black and look bristly. It's becoming a very common problem - last time I was at RHS Wisley a lot of their rhododendron bushes were affected. Goodness knows how they keep on top of it there.

You can spray against the leaf hoppers, but I've always thought that seemed a bit harsh (and very unfriendly to the environment). The usual treatment is to pick off the affected buds and burn them, but try doing that when the rhododendron bush is twice as high as you are. And you always miss a few, in any case.

I think we'll just have to keep at it and get as many as we can, and hope the problem doesn't do for the rhododendrons altogether. After all, there's not much point in keeping these rather sombre shrubs in your garden if they aren't even going to flower.