Is this cabbage maggot on broccoli roots?

[Croila]

A week or so ago I noticed about three of my purple sprouting broccoli was wilting really badly. I thought I spotted some whitefly on the undersides of the leaves, but despite having washed them off, the plants completely died.

I pulled them up today and found these disgusting little maggoty things on the roots, which I'm wondering is cabbage root maggot?

I did google it and it seems they like cool, wet conditions, and it's certainly been cool and wet here in Edinburgh for the last month or so. And it's a clay soil, even though I dug in compost and some "well-rotted farmyard manure" from the garden centre before I put the brassicas in.

It's only a very tiny patch of ground my brassicas are in (need to get rid of all the grass!). I think a neighbouring pointed cabbage is now starting to wilt, and possibly my one remaining broccoli. I've only got one broccoli and three cabbage left in that patch now, along with about two kohl rabi and some leeks, and I really want to know how to clear these dratted maggots out completely and save my other plants there.

Also, do these disgusting things spread to tatties? Cause my brassicas are right next to the tattie patch and I'd be gutted if they die as well!!

I really don't know what to do with this wee patch of ground if all the brassicas get attacked, like, how to clean it out, get rid of the little blighters and make sure they never come back, so if anyone can advise me what to do here, I'd be so grateful!

Of course, something was GOING to go wrong ... This is my first year of trying to grow veg, and that bit of ground has never been used before. I'm wondering whether to just build another enclosed square foot bed over it, filled with compost, and ignore that stupid bit of soil *sigh*

Yours despondently,
Croila

[SueA]

Hi Croila, yes they definitely look like cabbage root fly larvae. They'll attack your cabbage & kohl rabi in there as well but shouldn't affect the leeks or potatoes. There isn't any chemical solution & it's a bit late to try anything now as they've got a hold but I'd not grow any brassicas again for a while where you've got them now & when you plant out any brassicas, cabbage, cauli, broccoli etc. put small collars around the stems as soon as you plant them out. You can buy 'cabbage collars' or make your own out of strong cardboard, roof felt, bits of old carpet etc., just cut a circle about 4 inches in diameter, cut a slit into the centre & a few little cuts radiating out about half an inch & fit this around the base of the stem. This means that when the cabbage root fly lands at the base of the plant to lay it's eggs they stay on top of the collar & dry out & die instead of sitting on the soil where they burrow down when they hatch. You can also grwo everything under horticultural fleece which stops the flies getting in but this isn't always very practical.

[gojiberry]

I have had a lot of problems with this pest this year. As soon as I see a plant wilting I dig it out with a trowel and try to take out all the soil around the plant as well. The whole lot then goes into a bucket with a suitable pest control solution. The roots are washed of ensuring there are no grubs left and then the plant is re-planted. Even if the grubs have only left a twiggy root the plant usually grows more roots. Obviously it sets the plant back by several weeks but it helps stagger the cropping.

Ian

[Two_Sheds]

I get them on my radishes and turnips (can't grow either during the summer months) but not on my cabbagey things: I think because I grow them pretty big before I plant them out.

Don't be dispirited: brassicas are difficult.

[Croila]

Thank you for the replies, everyone, I really appreciate it. So ... cabbage root fly larvae, UGH! How utterly disgusting!

I lost another broccoli and cabbage to it yesterday but unfortunately I didn't get on the computer to see gojiberry's suggestion of digging it up and washing the grubs off the roots before I howked them out of the ground and chucked them out. I've got two cabbages left in that patch now, and if I can figure out what "suitable pest control solution" to put on them, I think I'll transplant them somewhere else, see if I can salvage them.

SueA, thank you for telling me about the cabbage collars - I'll definitely try them. I've got about eight spring cabbage seedlings on the go at the moment which I'm trying to keep in pots until my tatties are lifted, then I'll put them in there. I really love spring cabbage (well, not as much as cake, it is a vegetable after all!) so I'm really keen to make a go of growing these things successfully. I've bought some fleece too, so hopefully if I try as much damage limitation as I can, it might work!

Two Sheds, that's a good idea, growing them big before planting out. I'll definitely bear that in mind.

Thank you!