Slow painting

Tuesday, 4 August 2009

Raspberry removal

The raspberry situation has been going from bad to worse. Plentiful berries, but malformed, scabby fruit, fruit withering before it can ripen, dry and brittle canes, wilting top-growth, yellow-mottled leaves, this season's green canes snapping, and the biggest yuck factor, pale wriggly larvae in the berries. Any unaffected berries we've been able to find have been delicious and sweet, so it took us a while to accept that the canes had to come out.

Researching the cause has thrown up a nexus of ghastly possibilities. Ken Muir's 'Grow Your Own Fruit' has a lurid 20 page section on pests and diseases, with the sort of photos of bugs and beasties that when I was young made me try to turn the page of National Geographic magazine without touching the technicolour specimens displayed for my education.

By the time I'd finished with Ken's pests and diseases, I'd turned into a raspberry hypochondriac. It seems that our canes have not just one, but several afflictions, each more horrible than the last. Raspberry beetle: that's obvious because of the larvae, which as Ken says more graphically than is perhaps necessary, "can often be seen crawling around the punnet after the fruits have been picked." "Ultimately, there will be many small malformed fruits and heavy crop losses...Attacked drupelets turn brown and hard...The presence of the grub inside the fruit renders (for most people) the fruit inedible." We're definitely in the 'most people' category here, and we've got all these symptoms.

But wait! There's also raspberry leaf and bud mite. "The feeding on the leaves gives rise to distortion and irregular yellow blotching on the upper surface of leaves which to the inexperienced observer can be confused with virus infection. Apical buds of young canes are sometimes killed, leading to the development of weak lateral shoots. Attacks on fruits cause irregular drupelet development, uneven ripening and malformation." Yes, yes and yes.

Here's raspberry cane midge: "The failure of canes to break into leaf at the end of the winter and the wilting of the fruiting canes at any time between bud burst and picking are the obvious signs that has been an infestation by cane midge during the previous summer."

We've got the lot - larvae, blotching, wilting, distortion, the failure of the other row to break into leaf at all. Ken notes again and again, with some regret, "There are no label approved chemicals available to the amateur gardener for this pest." So we followed one of his solutions, which was to cut off all growth at ground level, to be followed by cultivation of the ground around the stools over the winter to expose overwintering bugs to the birds.

Taking a chance because they've outgrown their temporary pot, I put in the six new canes of Tulameen into the row we'd dug out earlier. I realise now that I left them with too much top growth, but I'll cut them back next visit, so that they're encouraged to throw out more growth from the root.

Beyond the new row of rasps the strawberry bed is all vigorous green leaf. Time for that to come off, now that fruiting is over. The season is turning.


donna said...

Maybe Ken Muir visited your raspberry patch before writing 'Grow Your Own Fruit'. Hardly anything tastes better than a perfect, delicious, sweet raspberry. You've turned this bad situation into an interesting read. I always enjoy my visits to your blog.

June said...

Oh, I'm sorry! Maybe the new canes will prove hardier! Now I've got to go check out those tiny green worms on ours...uh-oh.

Kris said...

I'm so sorry to learn you've lost your crop. Take some comfort that they did not falter from one single attack but that it took a whole slew of nasties to do them in.

Thank goodness for the gardener's mantra: "There's always next year..."

Peggy said...

Its an ongoing battle between slugs and pests. Your post should be flagged under raspberry diseases as it is pretty comprehensive! I am interested in your comment about the strawberries, time for the leaves to come and why??

New England Girl said...

So sorry to hear about the raspberries! I would be terribly disappointed. I discovered some raspberry bushes far after I had somehow discovered the black raspberry bushes... much to my dismay, they were past their prime and most were beyond picking. It was such a shame! I'm in the process of weeding out the area around them, cutting them back and making sure I know where to look next season!

I hope you have better luck with yours, too, next season. :)