Sunday, May 27, 2007

Club root on kohlrabi

Clubroot on Brassicas

So so disappointed ... I had a look at my kohlrabi this morning and something prompted me to pull two up. Sad to say that they seem heavily afflicted with clubroot. I didn't lime before planting and I have no idea what the gardener before me planted in the area that is now occupied by my cauliflower, cabbage and kohlrabi.

Apparently he planted brassicas. It seems I may have also shot myself in the foot by accepting seedlings from a fellow gardener - she may not have started hers off in sterile potting compost and the fungus could have been present even before they reached my garden.

You can see more pictures of the afflicted roots here.

Tomorrow I have the wonderful task of either going back and pulling out all of my brassicas to try and contain the spread or just leaving them alone and hoping for the best for the rest of this season.

Oh, and the three trays of broccoli and cauliflower seedlings I have here waiting to go in the ground? I guess they'll be ... not.

In the autumn I can heavily lime the brassica area, which will be a different patch in my rotation and then try again next year.

Here's another useful factsheet. And in case you wanted to know, clubroot is called 'knolvoet' in Dutch.


Exmonkey said...

I've heard that wrapping the roots in cabbage leaves and then planting helps.

Have you looked at: the forum has loads of good advice.

Ashleigh said...

I saw lots of liming going on late in February on the allotment so I imagine that they were liming for clubroot. I'm going to ask the resident old men what they think about whether I should pull up my plants and use the space for something more profitable (space and time wise) or if I should persevere.

Thanks for the link - taking a look now :)

..Vertine? said...

ewww that looks bad :( have you decided what to do?

jansmoestuin said...

Dear gardener,

Club root is the most terrible disease you can have on your vegetable garden. It can last over 12 years! Almost all alotments on sandy soil are contaminated.

Liming will only help a little bit. The good news is that winter brassica's like our "Boerenkool" and Brussels sprouts are less affected by club root. Also the very early pointed brassica "Spitskool" is less affected because of the lower temperatures during growing. I also have good experience with overwintering cauliflower and "spitskool".

My experience is that you can grow brassica's by digging a big hole putting lots of lime and than fill it with non contaminated preferably heavy soil and cover again with lime. Even with this system you will multiply clubroot in your garden. Of course very long rotations will help a bit more. But clubroot will be in the soil at least a meter from the infected cabage plant.

Be carefull with all brassica's. Cauliflower and especialy Chinese cabage are very susceptible.

I wish you all the best with your brassica's next time.

Kind regards from Jansmoestuin.

Ashleigh said...

Thanks so much Jan! I pulled up a few other plants to check. The spitskool are unaffected. They have a normal, if somewhat undersized root system.

The kohlrabi next to the affected plants seem to be unaffected. I haven't pulled up any cauliflower yet.

I've decided to leave the cauliflower in for the rest of the season and I'll give up on the brassicas for the foreseeable future.

I gave all my broccoli and winter cauliflower plants away to a neighbouring gardener who doesn't seem to care about rotations/worrying about diseases/etc.

My allotment is on the polder - very heavy clay soil. I spoke to some older gardeners and they say that the club root problem is everywhere on the site, just that some people don't care!