Weeding the Web

Cabbage white caterpillars: handpicked and trying to escape

How shall I put this?   AAAAAHHHHH!

Slugging it out in the garden

Slugs are certainly big this year, in more ways than one. Not only have I encountered some of the biggest bruisers I've ever seen in the garden, but this year's population explosion has also featured in national press.  In a supreme example of understatement, a spokesman for the National Farmers' Union, even managed, "They're not good news."

No, indeed. Nick Bailey, head gardener at the Chelsea Physic Garden, has reported this as the worst year of his 22-year-long gardening career, with slugs and snails a large part of that, and, helping out at my local horticultural society store recently, I found myself selling more slug pellets than anything else to some very desperate people.

Now, the manufacturer of Nemaslug has announced that it's run out and may not be available until next season.  Here's what Nemasys have put on their website:

Codling moths gather early - or do they?

Bright sunshine, glorious warmth. What else to do but relax in the recliner, gaze languidly up into the apple tree, and "What the...?!?"

I counted 15 of them: small, dark moths with extraordinarily long antennae. I'd have thought them cute, but for their intense concentration on a tree that contributes substantially to our food supply. Anything that focussed and that numerous just has to be bad, doesn't it?

But what were they?  Seriously hampered by the fact that they were too high to see properly, and wouldn't stay still long enough for me to snap a close-up, I first plumped for the codling moth as the main apple pest known to me, but they would be rather early. Here we were at the end of April and the RHS tells us that they emerge in late May-June (to lay eggs on or near developing fruits from June to mid-July).

Overwintering peppers and chillies

If you grew peppers this year, chances are that you’ve still got a tired-looking plant hanging around with the odd fruit still clinging to it. You could chuck it on the compost, but how about the alternative?

The Chile Man, with a database of 3729 peppers and chillies, is chock full of information, including how to overwinter your peppers. It could be worth it, as peppers, it seems, nearly always produce more fruit in their second year.

Snails' homing instinct foiled!

Just a quickie, following my last post about Ruth Brooks’ research into homing snails.

To those whose bowling arm isn’t quite up to sending the little pests the requisite 300 feet, a letter in last Saturday’s Daily Telegraph might be of interest.

Tristan Gooley wrote to say that scientists have shown that snails lose their sense of direction if shaken in a bag.

So, a quick jiggle courtesy of Mr Sainsbury and back to pouring them over the fence?

How to combat tomato blight

My very own sketch of Bob Flowerdew's blight protection shelter

So, talking about Blightwatch as we were, supposing there is a blight warning? What can you do? 

 

The Potato Council offers a pdf of Leisure Growers’ Advice on how to avoid blight, which includes photographs to aid identification. In their words, “The most effective control for the spread of infection is warm, dry and sunny weather.”

But, in the absence of that, they suggest repeated applications of copper-containing fungicides, such as Dithane 945 and Bordeaux Mixture.

How to control Potato Blight is one of the Top Ten subjects that come up again and again on Gardeners’ Question Time.

Matthew Biggs suggests various tactics, most of which you should have implemented before the dreaded warning. These include avoiding sheltered sites (presumably because it reduces the possibility of a hot and humid patch with its very own Smith periods), planting wider apart, and looking for early signs on neighbours’ crops and spraying with Bordeaux mixture before the blight reaches yours.

Blightwatch - so you know what's coming

I recently received my second Blightwatch Alert of the year. If you grow tomatoes and potatoes and haven’t already signed up to this service, you should as, once you have, you’ll get warnings of Smith periods, which are perfect times for blight to flourish.

For anyone who doesn’t know, a full Smith period occurs when the temperature during at least 2 consecutive days is 10°C or more, and relative humidity is greater than 90% for at least 11 hours each day.

Back in August 2007, I wrote about Blightwatch and Smith periods for Organic Gardening magazine (sadly defunct) and spoke to Steve Gerrish, Information Resources Manager at the British Potato Council. He said, “If there’s a spore on a leaf at the beginning of a Smith Period, then it will have germinated by the end, but it’s all risks and probabilities. A blight spore requires free water on a leaf in order to germinate. The Smith period is an estimate of a high-risk period.” It’s also why you should always water tomatoes at the base, so the leaves don’t harbour any “free water”.

So, even if you receive a warning, the occasional Smith Period isn’t a reason to panic, as it won’t automatically result in blight ravaging your plants. However, if periods occur every 7 to 10 days, that’s serious, as blight takes 7-10 days to develop and sporulate (excellent word, must repeat it)…sporulate again, so it thrives in such conditions.

Blightwatch also alerts you to Near Misses, when conditions are considered almost perfect. These need to be noted too, as your plants may be situated in a spot that, with the help of such climatic conditions, nurtures its own personal Smith periods.

So, forewarned is forearmed! But forearmed with what?

Something for the next blogpost, I think.