Monday, 1 August 2011

Next year's Broccoli under attack

A few days ago I finally removed the last of my Broad Beans to make space to plant out my Purple Sprouting Broccoli plants, which have been languishing in smallish pots for far too long. Having brassicas follow legumes in your crop-rotation plan is good, because the roots of the peas and beans fix nitrogen in the soil, which is used by the leafy brassicas later on.

Newly planted brassicas surrounded by young Endives

Regular readers will know by now that I always sow more seeds and raise more seedlings than I can possibly use, just so that I have the flexibility to choose the best specimens, and to replace any casualties. I had 12 Purple Sprouting Broccoli (PSB) plants but I know that I can only fit 6 into one of my 1-metre x 2.4-metres raised beds, so I had 100% spare. This was just as well, in view of what happened later (which I'll explain in a minute). I also put in 4 Cavolo Nero plants, chosen from 8 available. These never get as big as the PSB, and they usually get used up before Christmas, so there ought to be enough room to accommodate them OK. This is what they looked like just after planting. Healthy and strong-looking.

Purple Sprouting Broccoli

Cavolo Nero
Anyway, I thought I had done well getting everything sorted, but to my dismay it was only a matter of a couple of hours before several of the previously healthy brassicas began to wilt in a big way. Like this:

Actually, the wilting got even worse, so my photos perhaps don't adequately convey the seriousness of the problem. I knew this would be the result of infestation by the maggots of Cabbage Root Fly, which attack the roots of the plants. I carried out a "Post Mortem" examination of some of the casualties to confirm my diagnosis and this is what I found. The root system of the little brassica plants ought to be strong and well-developed by now, but it was almost entirely absent. With nothing to send up moisture and nutrients to the leaves it was no wonder they were dull and lifeless.

What remained of the roots was riddled with little white maggots. Yuck!

To be honest, this happens every year to a greater or lesser degree. I hope that some of the plants will be strong enough to survive, but I can't count on it. I have already had to deploy a couple of the spares, but some of them are obviously infested too, and looking far from happy.

Cavolo Nero plants, not looking too good!

I'm not giving up just yet, and it's possible that at least some of the plants will pull through, but just to be on the safe side I have sowed some more seeds. It's a bit late to be doing that, but in an emergency, you have to take desperate measures. At this time of year seedlings will grow pretty quickly and they might - just might - get big enough in time to survive the Winter. Meanwhile, I will administer as much TLC as possible to the ailing "patients", giving them copious amounts of water to try to lessen the stress under which they have been placed by the insect attack.In retrospect it would have been a good idea to treat the seedlings with relevant pesticide, such as the relatively new "Nemasys Grow Your Own" multi-purpose pest-killer. You can also lessen the likelihood of the plants being attacked by protecting them with collars which you fit round the stems in order to stop the flies laying their eggs close to the plants. Note to self: take more precautions next year!

Just to add insult to injury, the garden today is full of white butterflies, queueing up to lay their eggs on my brassicas!


  1. Sorry for your brassicas. Well, the same type of maggots you show is found in Japan,too. The fight against bugs will never end,,,,.
    Pursuing 100% organic vegetables is quiet difficult even for professional gardeners so using moderate amount of pesticide is one of our options, I think.

  2. I'm not going to say anything about my brassicas as I dont want to tempt fate. Does it mean the root fly is in the ground or did it attack them in the pots. Does that mean you won't be able to use the same ground again for brassicas?

  3. So were the root fly in the plants already when you planted them out or did they attack at break neck speed once planted in the beds.

  4. I think the root fly grubs must have been in the pots with the plants. It has to be just coincidence that they struck at the same time as I planted them out. The plants are just about holding their own. They wilt badly during the heat of the day, but they recover overnight. I think maybe 50% of them may survive. Here's hoping!

  5. We are over run by catterpillars, so I completly sympathise with you. It is so frustrating when all your effort goes to waste. But gardening and growing is a fantastic game and you never know what the next roll of the grow dice will bring!

    Martin :0)

  6. That's bad luck Mark. I've been lucky with my brassicas so far as I've only collared them haphazardly up until now. The carpet underlay in the garage goes unused, one of those winter jobs I don't seem to get round to making up the collars but I think I will this year!

  7. Oh dear. How disappointing. And I know how much you love your broccoli. Hope some of them survive.

  8. Sorry for the losses... I'm impressed you get so far from seed. Still working on that. Hope they survive!

  9. That is such a shame, it is hard work isn't it but I love your determination Mark!

  10. Hi Mark,

    Good post! Thanks! I've lost a few brassicas like that in my two years of growing and i never had any idea what it was that caused it.

    I shall have to get a few collars out of some old carpet i have here.


  11. Mark, that sucks. I don't know if that's an expression you use there, but it is a brilliant one that covers many dreadful happenings.

    I know how much you adore your PSB, and my fingers are crossed that the ones you have sown are not too late. Broccoli, tomatoes, there are many casualties in the garden this year.

  12. A real bummer. Hope the other plants you have will survive. I think I had the same sort of problem with some of my purple queen dwarf bean plants earlier in the year. Darn pests.

  13. Hope your new seeds will catch up and pick up growth fast.

  14. Sorry about your broccoli Mark, they looked so healthy. I've had problems too, again with apparently healthy plants already being infected before I got them in to the protected enclosure. Very annoying. Hope your late sowing works OK.

  15. never seen these in Victoria, Australia thank goodness. we do have those nasty white butterflies though, not looking forward to their return as the weather warms.

  16. Mark thanks for sharing. I have not planted brassicas before. I am thankful folks like you share struggles so folks like me can learn. I hope your 50% make it.

  17. We've had the root fly. Heartbreaking. We've had some success with collars. Another tip is to grow the plants REALLY big before you plant them out (assuming you can find a root fly free area to grow the plants - our cold frame works well). When they're got a really large root system at the start they seem to be able to withstand a root fly attack a little better.
    Also, earthing up the stems at the first sign of wilting. Sometimes they can grow some emergency roots higher up!


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