Brasicca Problems

[Katnap]

Hi,

I am currently having problems with my broccoli (calabrese), brussell sprouts and cabbage flopping over and changing to yellow and purplish mottled. Over the last 2 week it has affected 5 plants the others nearby seem quite happy.

I found an old post below from 2007 saying it may be Manganese or magnesium deficiency or aphids.

http://www.growfruitandveg.co.uk/gra...aves_7078.html

The brassicas were started off indoors the transplanted out at least a month ago into pockets of new MPC dug into clay. I have been feeding them with liquid fertilizer. They are near some overwintered broad beans so I don't doubt there are aphids about but the plants closest to the beans are unaffected. Below is a picture



Regards,

[Greenleaves]

It may be a deficiency... or indeed a pest in the soil. Did you prepare the site before planting the brassicas out?

It could even be the ph of your soil

[veggiechicken]

Could you dig one up and look at the roots? Just wondering if the problem is below ground?

[bario1]

I wouldn't feed plants that small, maybe you've overfertilised them?

[Katnap]

Thanks for the fast replies.

I have been out to take some more pictures






Greenleaves, prior to this year the soil was grass on clay I double dug and put the turf upside down at the bottom. as the clay was quite chunky I made holes in the clay and filled with MPC.

Veggiechicken, attached is a picture of the roots they do appear to be small compared to the size of the plant. also it broke at the soil line with very little force when removing it.

[Greenleaves]

Looking at the roots i would guess you have pests in your soil or possibly cabbage root fly but no maggots are visable. The lack of roots also suggests being planted in MPC they are rocking in the wind which is breaking of the root fibres

[burnie]

I would suggest that they may be lacking alkali, liming would have helped prior to planting, not sure what can be done now other than check soil ph.

[Snadger]

Has the compost dried out at any time? They appear to be droughted? I pocket of MPC won't have the strength to keep the plants vertical in the clay methinks. IMHO you would have been better almeliorating the MPC into the clay loam before planting direct in it.

[Snoop Puss]

In image 20170522_200957.jpg (top one of your post at 7.41 pm on 22 May), does it look to you like the original tap root has been damaged and the plant is doing its best by forming a new tap root? It's hard to see such details in an image.

[Greenleaves]

The more I look the more I am convinced its wind rock, as Snadger and I have already said MPC affords limited if any anchorage.

My advice would be to add plenty of organic material to your beds over the winter but I am fortunate not to have heavy clay soil so someone with experience of clay would be better placed to advise.

[happyhumph]

I have clay soil which like most clays is nutrient rich. I've found brassicas generally do well, but I've improved my soil by digging in and mulching with lots of organic material. Would agree pockets of mpc probably aren't helping with wind rock. With clay clubroot is much less likely so agree probably wind rock.

[Potstubsdustbins]

I grow mostly in MPC and have found over the years I have to be very careful about getting the growing medium firm enough for brassica's. I now have a 18" long piece of floorboard with a handle attached to help with the process. At the beginning of the season I sieve and feed the bed then batter it down hard, I do this again two weeks later and then once more just before planting. Finally I shelter the plantlets until they have settled in.

[Katnap]

Thank you all for the replies. Sorry for not coming back sooner but I am getting married tomorrow so have been pulled from pillar to post.

Wind rock could be possible the plants suffering the most are at the front of the bed and the ones between two rows of broad beans seem quite happy also the ones a bit closer to the fence seem happy.

I regularly plant in pockets or containers of MCR without problem but brassicas do have larger sail like leaves. next year I will try them in a clay/MPC mix and some in just clay to see what happens.

Thanks for the help.

[vixylix]

Have a fantastic wedding day Kat!

[1Bee]

Congratulations and enjoy your day!

I think to be honest brassicas would prefer the clay to the MPC. They like to be firm, neutral to alkali, which is more likely in clay.