Cabbage root fly

It looks like the dreaded bug has got into my Swedes, they keeled over and tiny white grubs in the roots. The same thing happened with one brassica plant, so far the others are OK. Any tips on how to get rid of the beasties and how to prevent them coming back next year. I should point out that both plants are in new plots. (not used for veg before) TIA

 

JWK is right, it's probably too late to do anything for this year's crop.

In the Bad Old Days, there were insecticides for root pests and I used to apply one called Bromophos when planting brassica seeds or plants. I'm pretty sure it's banned now.

When planting brassicas which have a stem, I put collars around the stems of young plants. I used to make my own collars out of plastic sheeting and carpet underlay but now I buy the Arthur Bowers ones. They're dirt cheap, fit better and look better. So far, they also work better, it seems.

Collars won't work on root crops of course and so fleece is your best bet.

 

Many thanks for your replies. I remember using Bromophos some years ago but I do try to be organic (not allways succeeding). I like the idea of collars and for the benefit of others I have found them at Dr. Fothergills, T & M and Ebay. They are called Cabbage Collars. I practice crop rotation and will certainly use collars next year. Just as another point, I remember my Grandad used to spray the ground with Jeyes Fluid during the close season to "clear the bugs". Comments on this practice would be appreciated.

 

Maltaron

Jeyes Fluid? Ah, happy days! I've sprayed and deluged many, many gallons of Jeyes Fluid over my garden in the past, to very good effect. I still have my Jeyes Fluid booklet which told me of all the uses it had in the garden. It makes nostalgic reading.

Sadly, Jeyes Fluid is no longer licensed for use in this way. It is not sanctioned for use on any vegetation or as a soil drench. Whether it has a different formula now or the manufacturers did not want the hassle of trying to make it conform to the new European standards, I don't know. It was very useful stuff but now it's sold as just a hard surface garden/farm disinfectant.

 

According to their website you can still use jeyes on greenhouses, water butts, and the ready to use one has "For smaller areas, Jeyes Fluid is now available as a handy pre-diluted ready-to-use trigger spray. It is aimed at simplifying the lives of active gardeners."

 

JWK

Jeyes Fluid can certainly be used in greenhouses to clean frames, staging, pots, seed trays etc., but my tin makes no mention of soil drenching and contains no dilution for that purpose.

In the past when I had an old fashioned lean to greenhouse, I would routinely drench the side beds with a one dessert spoonful per gallon solution. I also used to drench my vegetable patch every few years. I wouldn't do it now because Jeyes seem to have excluded it from their list of uses. It also kills a lot of worms and I need to boost my worm population.

My tin says "Avoid contact of product with plantlife" - and yet I used to spray annuals, shrubs and root crops with it regularly. The instructions also say "Do not use if pregnant" so I think we've entered a new era where manufacturers play ultra safe.

 

.

I planted some more Autumn Cauli's, winter cabbage and broccoli about two weeks ago!
On Friday I noticed some off them were wilting and purple coloured.
When I gave them a slight tug they came out off the soil easily.
They had no roots on them, stripped clean and some off the dreaded grubs on the stems.
I pulled out any more that was looking weakly and destroyed them.

Then I sprayed around the base of the surviving one with insecticide with the nozzle set to a JET!
This way I don't use a lot of insecticide and get it where it will do most good!

None of the brasssicas planted out earlier have been affected, neither the one already harvested or the others partially grown.

One way is to use collars, put around each plant at soil level as the young plants are put in, it is fiddly if you are planting lots of plants, but it does work!

Cheers

 

A less fiddly alternative to individual collars is to use either a covering sheet of weed surpressing membrane or black polythene. I used to make collars out of builders brick damp proofing roll which worked OK but was a fiddle to place but now use a full bed covering of perforated black plastic. Works a treat and also keeps the bed clear of weeds.

 

Does netting the Brassicas against Cabbage White Butterfly keep out the Root fly too? (Depends on the size of the mesh I guess Doh! but I wonder what that needs to be?)

 

It most probably does Kristen, but I'm using a belt and braces solution:D